Difference between revisions of "Module:Citation/CS1/Date validation"

From Shipbucket Wiki
Jump to: navigation, search
(synch from sandbox;)
m (1 revision imported)
 
(One intermediate revision by one other user not shown)
Line 6: Line 6:
 
]]
 
]]
  
local is_set, in_array; -- imported functions from selected Module:Citation/CS1/Utilities
+
local is_set, in_array; -- imported function from selected Module:Citation/CS1/Utilities
local cfg; -- table of tables imported from slected Module:Citation/CS1/Configuration
+
 
  
 
--[=[-------------------------< I S _ V A L I D _ A C C E S S D A T E >----------------------------------------
 
--[=[-------------------------< I S _ V A L I D _ A C C E S S D A T E >----------------------------------------
Line 21: Line 21:
 
adding 24 hours gives 2015-01-03T00:00:00 – one second more than tomorrow
 
adding 24 hours gives 2015-01-03T00:00:00 – one second more than tomorrow
  
This function does not work if it is fed month names for languages other than English.  Wikimedia #time: parser
+
This function does not work for languages other than English.  Wikimedia #time: parser apparently doesn't understand
apparently doesn't understand non-Engish date month names. This function will always return false when the date
+
non-Engish date month names. This function will always return false when the date contains a non-English month name
contains a non-English month name because good1 is false after the call to lang.formatDate(). To get around that
+
because good1 is false after the call to lang.formatDate.
call this function with YYYY-MM-DD format dates.
+
 
 +
For the time being, to use this function, supply it with YYYY-MM-DD format dates.  See
 +
[[bs:Modul:Citation/CS1/Date validation/igralište]] for one possible solution.
  
 
]=]
 
]=]
Line 42: Line 44:
 
return false; -- one or both failed to convert to unix time stamp
 
return false; -- one or both failed to convert to unix time stamp
 
end
 
end
 
+
 
if 979516800 <= access_ts and access_ts < tomorrow_ts then -- Wikipedia start date <= accessdate < tomorrow's date
 
if 979516800 <= access_ts and access_ts < tomorrow_ts then -- Wikipedia start date <= accessdate < tomorrow's date
 
return true;
 
return true;
Line 58: Line 60:
  
 
local function get_month_number (month)
 
local function get_month_number (month)
return cfg.date_names['local'].long[month] or cfg.date_names['local'].short[month] or -- look for local names first
+
local long_months = {['January']=1, ['February']=2, ['March']=3, ['April']=4, ['May']=5, ['June']=6, ['July']=7, ['August']=8, ['September']=9, ['October']=10, ['November']=11, ['December']=12};
cfg.date_names['en'].long[month] or cfg.date_names['en'].short[month] or -- failing that, look for English names
+
local short_months = {['Jan']=1, ['Feb']=2, ['Mar']=3, ['Apr']=4, ['May']=5, ['Jun']=6, ['Jul']=7, ['Aug']=8, ['Sep']=9, ['Oct']=10, ['Nov']=11, ['Dec']=12};
0; -- not a recognized month name
+
return long_months[month] or -- if month is the long-form name
 +
short_months[month] or -- if month is the short-form name
 +
0; -- misspelled, improper case, or not a month name
 
end
 
end
  
Line 68: Line 72:
 
returns true and date value if that value has proper dmy, mdy, ymd format.
 
returns true and date value if that value has proper dmy, mdy, ymd format.
  
returns false and 9999 (embargoed forever) when date value is not proper format; assumes that when |embargo= is
+
returns false and 9999 when date value is not proper format; assumes that when |embargo= is set, the editor
set, the editor intended to embargo a pmc but |embargo= does not hold a single date.
+
intended to embargo a pmc but |embargo does not hold a single date.
  
 
]]
 
]]
Line 86: Line 90:
  
 
returns a number according to the sequence of seasons in a year: 1 for Winter, etc.  Capitalization and spelling must be correct. If not a valid season, returns 0
 
returns a number according to the sequence of seasons in a year: 1 for Winter, etc.  Capitalization and spelling must be correct. If not a valid season, returns 0
 
Uses ISO DIS 8601 2016 part 2 §4.7  Divisions of a year for hemishpere-independent seasons:
 
21-24 = Spring, Summer, Autumn, Winter, independent of “Hemisphere”
 
 
These additional divisions not currently supported:
 
25-28 = Spring - Northern Hemisphere, Summer- Northern Hemisphere, Autumn - Northern Hemisphere, Winter - Northern Hemisphere
 
29-32 = Spring – Southern Hemisphere, Summer– Southern Hemisphere, Autumn – Southern Hemisphere, Winter - Southern Hemisphere
 
33-36 = Quarter 1, Quarter 2, Quarter 3, Quarter 4 (3 months each)
 
37-39 = Quadrimester 1, Quadrimester 2, Quadrimester 3 (4 months each)
 
40-41 = Semestral 1, Semestral-2 (6 months each)
 
 
  
 
]]
 
]]
  
 
local function get_season_number (season)
 
local function get_season_number (season)
return cfg.date_names['local'].season[season] or -- look for local names first
+
local season_list = {['Winter']=21, ['Spring']=22, ['Summer']=23, ['Fall']=24, ['Autumn']=24}; -- make sure these numbers do not overlap month numbers
cfg.date_names['en'].season[season] or -- failing that, look for English names
+
local temp;
0; -- not a recognized season name
+
temp=season_list[season];
 +
if temp then return temp; end -- if season is a valid name return its number
 +
return 0; -- misspelled, improper case, or not a season name
 
end
 
end
  
Line 113: Line 108:
  
 
local function is_proper_name (name)
 
local function is_proper_name (name)
return cfg.date_names['local'].named[name] or -- look for local names dates first
+
local name_list = {['Christmas']=31}
cfg.date_names['en'].named[name] or -- failing that, look for English names
+
local temp;
0; -- not a recognized named date
+
temp=name_list[name];
 +
if temp then return temp; end -- if name is a valid name return its number
 +
return 0; -- misspelled, improper case, or not a proper name
 
end
 
end
  
Line 216: Line 213:
 
Month pairs are expected to be left to right, earliest to latest in time.
 
Month pairs are expected to be left to right, earliest to latest in time.
  
All season ranges are accepted as valid because there are publishers out there who have published a Summer–Spring YYYY issue so ... ok
+
Similarly, seasons are also left to right, earliest to latest in time.  There is an oddity with seasons: winter is assigned a value of 1, spring 2, ...,
 +
fall and autumn 4. Because winter can follow fall/autumn at the end of a calender year, a special test is made to see if |date=Fall-Winter yyyy (4-1) is the date.
  
 
]]
 
]]
Line 225: Line 223:
 
 
 
if 0 == range_start_number then -- is this a month range?
 
if 0 == range_start_number then -- is this a month range?
range_start_number = get_season_number (range_start); -- not a month; is it a season? get start season number
+
local range_start_number = get_season_number (range_start); -- not a month; is it a season? get start season number
 
range_end_number = get_season_number (range_end); -- get end season number
 
range_end_number = get_season_number (range_end); -- get end season number
  
if (0 ~= range_start_number) and (0 ~= range_end_number) then
+
if 0 ~= range_start_number then -- is start of range a season?
return true; -- any season pairing is accepted
+
if range_start_number < range_end_number then -- range_start is a season
 +
return true; -- return true when range_end is also a season and follows start season; else false
 +
end
 +
if 24 == range_start_number and 21 == range_end_number then -- special case when season range is Fall-Winter or Autumn-Winter
 +
return true;
 +
end
 
end
 
end
return false; -- range_start and/or range_end is not a season
+
return false; -- range_start is not a month or a season; or range_start is a season and range_end is not; or improper season sequence
 
end
 
end
-- here when range_start is a month
+
 
 
range_end_number = get_month_number (range_end); -- get end month number
 
range_end_number = get_month_number (range_end); -- get end month number
 
if range_start_number < range_end_number then -- range_start is a month; does range_start precede range_end?
 
if range_start_number < range_end_number then -- range_start is a month; does range_start precede range_end?
Line 351: Line 354:
 
]]
 
]]
  
local function check_date (date_string, tCOinS_date, test_accessdate)
+
local function check_date (date_string, tCOinS_date)
 
local year; -- assume that year2, months, and days are not used;
 
local year; -- assume that year2, months, and days are not used;
 
local year2=0; -- second year in a year range
 
local year2=0; -- second year in a year range
Line 365: Line 368:
 
if 12 < tonumber(month) or 1 > tonumber(month) or 1582 > tonumber(year) or 0 == tonumber(day) then return false; end -- month or day number not valid or not Gregorian calendar
 
if 12 < tonumber(month) or 1 > tonumber(month) or 1582 > tonumber(year) or 0 == tonumber(day) then return false; end -- month or day number not valid or not Gregorian calendar
 
anchor_year = year;
 
anchor_year = year;
 +
 
elseif date_string:match("^%a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month-initial: month day, year
 
elseif date_string:match("^%a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month-initial: month day, year
month, day, anchor_year, year=string.match(date_string, "(%a+)%s*(%d%d?),%s*((%d%d%d%d?)%a?)");
+
month, day, anchor_year, year=string.match(date_string, "(%a+)%s*(%d%d?),%s*((%d%d%d%d)%a?)");
 
month = get_month_number (month);
 
month = get_month_number (month);
 
if 0 == month then return false; end -- return false if month text isn't one of the twelve months
 
if 0 == month then return false; end -- return false if month text isn't one of the twelve months
 
 
elseif mw.ustring.match(date_string, "^%a+ +[1-9]%d?[%-][1-9]%d?, +[1-9]%d%d%d%a?$") then -- month-initial day range: month day–day, year; days are separated by endash
+
elseif date_string:match("^%a+ +[1-9]%d?–[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month-initial day range: month day–day, year; days are separated by endash
month, day, day2, anchor_year, year=mw.ustring.match(date_string, "(%a+) +(%d%d?)[%-](%d%d?), +((%d%d%d%d)%a?)");
+
month, day, day2, anchor_year, year=string.match(date_string, "(%a+) +(%d%d?)–(%d%d?), +((%d%d%d%d)%a?)");
 
if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;
 
if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;
 
month = get_month_number (month);
 
month = get_month_number (month);
Line 379: Line 383:
  
 
elseif date_string:match("^[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day-initial: day month year
 
elseif date_string:match("^[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day-initial: day month year
day, month, anchor_year, year=string.match(date_string, "(%d%d*)%s*(%a+)%s*((%d%d%d%d?)%a?)");
+
day, month, anchor_year, year=string.match(date_string, "(%d%d*)%s*(%a+)%s*((%d%d%d%d)%a?)");
 
month = get_month_number (month);
 
month = get_month_number (month);
 
if 0 == month then return false; end -- return false if month text isn't one of the twelve months
 
if 0 == month then return false; end -- return false if month text isn't one of the twelve months
  
elseif mw.ustring.match(date_string, "^[1-9]%d?[%-][1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day-range-initial: day–day month year; days are separated by endash
+
elseif date_string:match("^[1-9]%d?–[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day-range-initial: day–day month year; days are separated by endash
day, day2, month, anchor_year, year=mw.ustring.match(date_string, "(%d%d?)[%-](%d%d?) +(%a+) +((%d%d%d%d)%a?)");
+
day, day2, month, anchor_year, year=string.match(date_string, "(%d%d?)–(%d%d?) +(%a+) +((%d%d%d%d)%a?)");
 
if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;
 
if tonumber(day) >= tonumber(day2) then return false; end -- date range order is left to right: earlier to later; dates may not be the same;
 
month = get_month_number (month);
 
month = get_month_number (month);
Line 391: Line 395:
 
year2=year;
 
year2=year;
  
elseif mw.ustring.match(date_string, "^[1-9]%d? +%a+ [%-] [1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day initial month-day-range: day month - day month year; uses spaced endash
+
elseif date_string:match("^[1-9]%d? +%a+ – [1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day initial month-day-range: day month - day month year; uses spaced endash
day, month, day2, month2, anchor_year, year=mw.ustring.match(date_string, "(%d%d?) +(%a+) [%-] (%d%d?) +(%a+) +((%d%d%d%d)%a?)");
+
day, month, day2, month2, anchor_year, year=date_string:match("(%d%d?) +(%a+) – (%d%d?) +(%a+) +((%d%d%d%d)%a?)");
 
if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end -- date range order is left to right: earlier to later;
 
if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end -- date range order is left to right: earlier to later;
 
month = get_month_number (month); -- for metadata
 
month = get_month_number (month); -- for metadata
Line 398: Line 402:
 
year2=year;
 
year2=year;
  
elseif mw.ustring.match(date_string, "^%a+ +[1-9]%d? [%-] %a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month initial month-day-range: month day – month day, year;  uses spaced endash
+
elseif date_string:match("^%a+ +[1-9]%d? – %a+ +[1-9]%d?, +[1-9]%d%d%d?%a?$") then -- month initial month-day-range: month day – month day, year;  uses spaced endash
month, day, month2, day2, anchor_year, year=mw.ustring.match(date_string, "(%a+) +(%d%d?) [%-] (%a+) +(%d%d?), +((%d%d%d%d)%a?)");
+
month, day, month2, day2, anchor_year, year=date_string:match("(%a+) +(%d%d?) – (%a+) +(%d%d?), +((%d%d%d%d)%a?)");
 
if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end
 
if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end
 
month = get_month_number (month); -- for metadata
 
month = get_month_number (month); -- for metadata
Line 405: Line 409:
 
year2=year;
 
year2=year;
  
elseif mw.ustring.match(date_string, "^[1-9]%d? +%a+ +[1-9]%d%d%d [%-] [1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day initial month-day-year-range: day month year - day month year; uses spaced endash
+
elseif date_string:match("^[1-9]%d? +%a+ +[1-9]%d%d%d – [1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then -- day initial month-day-year-range: day month year - day month year; uses spaced endash
day, month, year, day2, month2, anchor_year, year2=mw.ustring.match(date_string, "(%d%d?) +(%a+) +(%d%d%d%d) [%-] (%d%d?) +(%a+) +((%d%d%d%d)%a?)");
+
day, month, year, day2, month2, anchor_year, year2=date_string:match("(%d%d?) +(%a+) +(%d%d%d%d?) – (%d%d?) +(%a+) +((%d%d%d%d?)%a?)");
 
if tonumber(year2) <= tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later
 
if tonumber(year2) <= tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later
 
if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end -- year2 no more than one year in the future; months same style
 
if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end -- year2 no more than one year in the future; months same style
Line 412: Line 416:
 
month2 = get_month_number (month2);
 
month2 = get_month_number (month2);
  
elseif mw.ustring.match(date_string, "^%a+ +[1-9]%d?, +[1-9]%d%d%d [%-] %a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month initial month-day-year-range: month day, year – month day, year;  uses spaced endash
+
elseif date_string:match("^%a+ +[1-9]%d?, +[1-9]%d%d%d – %a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then -- month initial month-day-year-range: month day, year – month day, year;  uses spaced endash
month, day, year, month2, day2, anchor_year, year2=mw.ustring.match(date_string, "(%a+) +(%d%d?), +(%d%d%d%d) [%-] (%a+) +(%d%d?), +((%d%d%d%d)%a?)");
+
month, day, year, month2, day2, anchor_year, year2=date_string:match("(%a+) +(%d%d?), +(%d%d%d%d) – (%a+) +(%d%d?), +((%d%d%d%d)%a?)");
 
if tonumber(year2) <= tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later
 
if tonumber(year2) <= tonumber(year) then return false; end -- must be sequential years, left to right, earlier to later
 
if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end -- year2 no more than one year in the future; months same style
 
if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end -- year2 no more than one year in the future; months same style
Line 419: Line 423:
 
month2 = get_month_number (month2);
 
month2 = get_month_number (month2);
  
elseif mw.ustring.match(date_string, "^%a+ +[1-9]%d%d%d[%-–]%d%d%a?$") then -- special case Winter/Summer year-year (YYYY-YY); year separated with unspaced endash
+
elseif date_string:match("^%a+ +[1-9]%d%d%d–%d%d%a?$") then -- special case Winter/Summer year-year (YYYY-YY); year separated with unspaced endash
 
local century;
 
local century;
month, year, century, anchor_year, year2=mw.ustring.match(date_string, "(%a+) +((%d%d)%d%d)[%-]((%d%d)%a?)");
+
month, year, century, anchor_year, year2=date_string:match("(%a+) +((%d%d)%d%d)–((%d%d)%a?)");
 
if 'Winter' ~= month and 'Summer' ~= month then return false end; -- 'month' can only be Winter or Summer
 
if 'Winter' ~= month and 'Summer' ~= month then return false end; -- 'month' can only be Winter or Summer
 
anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years
 
anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years
Line 429: Line 433:
 
month = get_season_number (month);
 
month = get_season_number (month);
  
elseif mw.ustring.match(date_string, "^%a+ +[1-9]%d%d%d[%-–][1-9]%d%d%d%a?$") then -- special case Winter/Summer year-year; year separated with unspaced endash
+
elseif date_string:match("^%a+ +[1-9]%d%d%d–[1-9]%d%d%d%a?$") then -- special case Winter/Summer year-year; year separated with unspaced endash
month, year, anchor_year, year2=mw.ustring.match(date_string, "(%a+) +(%d%d%d%d)[%-]((%d%d%d%d)%a?)");
+
month, year, anchor_year, year2=date_string:match("(%a+) +(%d%d%d%d)–((%d%d%d%d)%a?)");
 
if 'Winter' ~= month and 'Summer' ~= month then return false end; -- 'month' can only be Winter or Summer
 
if 'Winter' ~= month and 'Summer' ~= month then return false end; -- 'month' can only be Winter or Summer
 
anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years
 
anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years
Line 437: Line 441:
 
month = get_season_number (month); -- for metadata
 
month = get_season_number (month); -- for metadata
  
elseif mw.ustring.match(date_string, "^%a+ +[1-9]%d%d%d +[%-] +%a+ +[1-9]%d%d%d%a?$") then -- month/season year - month/season year; separated by spaced endash
+
elseif date_string:match("^%a+ +[1-9]%d%d%d% – %a+ +[1-9]%d%d%d%a?$") then -- month/season year - month/season year; separated by spaced endash
month, year, month2, anchor_year, year2=mw.ustring.match(date_string, "(%a+) +(%d%d%d%d) +[%-] +(%a+) +((%d%d%d%d)%a?)");
+
month, year, month2, anchor_year, year2=date_string:match("(%a+) +(%d%d%d%d) – (%a+) +((%d%d%d%d)%a?)");
 
anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years
 
anchor_year=year..'–'..anchor_year; -- assemble anchor_year from both years
 
if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same
 
if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same
Line 452: Line 456:
 
end
 
end
  
elseif mw.ustring.match(date_string, "^%a+[%-]%a+ +[1-9]%d%d%d%a?$") then -- month/season range year; months separated by endash  
+
elseif date_string:match ("^%a+–%a+ +[1-9]%d%d%d%a?$") then -- month/season range year; months separated by endash  
month, month2, anchor_year, year=mw.ustring.match(date_string, "(%a+)[%-](%a+)%s*((%d%d%d%d)%a?)");
+
month, month2, anchor_year, year=date_string:match ("(%a+)–(%a+)%s*((%d%d%d%d)%a?)");
 
if (not is_valid_month_season_range(month, month2)) or (not is_valid_year(year)) then return false; end
 
if (not is_valid_month_season_range(month, month2)) or (not is_valid_year(year)) then return false; end
 
if 0 ~= get_month_number(month) then -- determined to be a valid range so just check this one to know if month or season
 
if 0 ~= get_month_number(month) then -- determined to be a valid range so just check this one to know if month or season
Line 476: Line 480:
 
end
 
end
  
elseif mw.ustring.match(date_string, "^[1-9]%d%d%d?[%-][1-9]%d%d%d?%a?$") then -- Year range: YYY-YYY or YYY-YYYY or YYYY–YYYY; separated by unspaced endash; 100-9999
+
elseif date_string:match("^[1-9]%d%d%d?–[1-9]%d%d%d?%a?$") then -- Year range: YYY-YYY or YYY-YYYY or YYYY–YYYY; separated by unspaced endash; 100-9999
year, anchor_year, year2=mw.ustring.match(date_string, "(%d%d%d%d?)[%-]((%d%d%d%d?)%a?)");
+
year, anchor_year, year2=date_string:match("(%d%d%d%d?)–((%d%d%d%d?)%a?)");
 
anchor_year=year..'–'..anchor_year; -- assemble anchor year from both years
 
anchor_year=year..'–'..anchor_year; -- assemble anchor year from both years
 
if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same
 
if tonumber(year) >= tonumber(year2) then return false; end -- left to right, earlier to later, not the same
 
if not is_valid_year(year2) then return false; end -- no year farther in the future than next year
 
if not is_valid_year(year2) then return false; end -- no year farther in the future than next year
  
elseif mw.ustring.match(date_string, "^[1-9]%d%d%d[%-–]%d%d%a?$") then -- Year range: YYYY–YY; separated by unspaced endash
+
elseif date_string:match("^[1-9]%d%d%d–%d%d%a?$") then -- Year range: YYYY–YY; separated by unspaced endash
 
local century;
 
local century;
year, century, anchor_year, year2=mw.ustring.match(date_string, "((%d%d)%d%d)[%-]((%d%d)%a?)");
+
year, century, anchor_year, year2=date_string:match("((%d%d)%d%d)–((%d%d)%a?)");
 
anchor_year=year..'–'..anchor_year; -- assemble anchor year from both years
 
anchor_year=year..'–'..anchor_year; -- assemble anchor year from both years
 
if 13 > tonumber(year2) then return false; end -- don't allow 2003-05 which might be May 2003
 
if 13 > tonumber(year2) then return false; end -- don't allow 2003-05 which might be May 2003
Line 499: Line 503:
 
else
 
else
 
return false; -- date format not one of the MOS:DATE approved formats
 
return false; -- date format not one of the MOS:DATE approved formats
end
 
 
if test_accessdate then -- test accessdate here because we have numerical date parts
 
if 0 ~= year and 0 ~= month and 0 ~= day and -- all parts of a single date required
 
0 == year2 and 0 == month2 and 0 == day2 then -- none of these; accessdate must not be a range
 
if not is_valid_accessdate (year..'-'..month..'-'..day) then
 
return false; -- return false when accessdate out of bounds
 
end
 
else
 
return false; -- return false when accessdate is a range of two dates
 
end
 
 
end
 
end
  
Line 553: Line 546:
 
local anchor_year; -- will return as nil if the date being tested is not |date=
 
local anchor_year; -- will return as nil if the date being tested is not |date=
 
local COinS_date; -- will return as nil if the date being tested is not |date=
 
local COinS_date; -- will return as nil if the date being tested is not |date=
local embargo_date; -- if embargo date is a good dmy, mdy, ymd date then holds original value else reset to 9999
+
local embargo_date = '9999'; -- if good dmy, mdy, ymd date then holds original value else 9999
 
local error_message = "";
 
local error_message = "";
 
local good_date = false;
 
local good_date = false;
Line 568: Line 561:
 
end
 
end
 
elseif 'date'==k then -- if the parameter is |date=
 
elseif 'date'==k then -- if the parameter is |date=
if v:match("^n%.d%.%a?$") then -- if |date=n.d. with or without a CITEREF disambiguator
+
if v:match("^n%.d%.%a?") then -- if |date=n.d. with or without a CITEREF disambiguator
 
good_date, anchor_year, COinS_date = true, v:match("((n%.d%.)%a?)"); --"n.d."; no error when date parameter is set to no date
 
good_date, anchor_year, COinS_date = true, v:match("((n%.d%.)%a?)"); --"n.d."; no error when date parameter is set to no date
 
elseif v:match("^nd%a?$") then -- if |date=nd with or without a CITEREF disambiguator
 
elseif v:match("^nd%a?$") then -- if |date=nd with or without a CITEREF disambiguator
Line 575: Line 568:
 
good_date, anchor_year, COinS_date = check_date (v, tCOinS_date); -- go test the date
 
good_date, anchor_year, COinS_date = check_date (v, tCOinS_date); -- go test the date
 
end
 
end
elseif 'year'==k then -- if the parameter is |year= it should hold only a year value
+
elseif 'access-date'==k then -- if the parameter is |access-date=
if v:match("^[1-9]%d%d%d?%a?$") then -- if |year= 3 or 4 digits only with or without a CITEREF disambiguator
+
good_date = check_date (v); -- go test the date
good_date, anchor_year, COinS_date = true, v:match("((%d+)%a?)");
+
if true == good_date then -- if the date is a valid date
 +
good_date = is_valid_accessdate (v); -- is Wikipedia start date < accessdate < tomorrow's date?
 
end
 
end
elseif 'access-date'==k then -- if the parameter is |date=
 
good_date = check_date (v, nil, true); -- go test the date; nil is a placeholder; true is the test_accessdate flag
 
 
elseif 'embargo'==k then -- if the parameter is |embargo=
 
elseif 'embargo'==k then -- if the parameter is |embargo=
 
good_date = check_date (v); -- go test the date
 
good_date = check_date (v); -- go test the date
Line 633: Line 625:
 
end
 
end
  
elseif mw.ustring.match(date_string, "%d%d%d%d[%-–]%d%d") then -- YYYY-YY date ranges
+
elseif date_string:match ("%d%d%d%d–%d%d") then -- YYYY-YY date ranges
 
local century;
 
local century;
date1, century, date2 = mw.ustring.match(date_string, "((%d%d)%d%d)[%-–]+(%d%d)");
+
date1, century, date2 = date_string:match ("((%d%d)%d%d)[%s%-–]+(%d%d)");
 
date2 = century..date2; -- convert YY to YYYY
 
date2 = century..date2; -- convert YY to YYYY
 
if year ~= date1 and year ~= date2 then
 
if year ~= date1 and year ~= date2 then
Line 660: Line 652:
  
 
local source_patterns = { -- this table holds patterns that match allowed date formats used to extract date components
 
local source_patterns = { -- this table holds patterns that match allowed date formats used to extract date components
['dmy'] = '^(%d%d?)%s+(%a+)%s+(%d%d%d%d)$',
+
['dmy'] = '(%d%d?)%s+(%a+)%s+(%d%d%d%d)',
['mdy'] = '^(%a+)%s+(%d%d?),%s+(%d%d%d%d)$',
+
['mdy'] = '(%a+)%s+(%d%d?),%s+(%d%d%d%d)',
['ymd'] = '^(%d%d%d%d)%-(%d%d)-(%d%d)$',
+
['ymd'] = '(%d%d%d%d)%-(%d%d)-(%d%d)',
 
}
 
}
  
Line 721: Line 713:
  
 
Date ranges, season dates, proper name dates are not currently supported.
 
Date ranges, season dates, proper name dates are not currently supported.
 
For i18n:  This code works only at en.wiki because os.date() doesn't support any languages other than English.
 
mw.getContentLanguage():formatDate() will work at non-English wikis only when the date format is yyyy-mm-dd. This is
 
the same issue that plagues is_valid_accessdate()
 
 
It is possible that a solution like that written for ht:Module:Citation/CS1/Date_validation date_name_xlate() could be applied to this problem
 
  
 
]]
 
]]
Line 740: Line 726:
 
end
 
end
 
 
for param_name, param_val in pairs (date_parameters_list) do -- for each date-holding parameter in the list
+
for param_name, param_val in pairs(date_parameters_list) do -- for each date-holding parameter in the list
if is_set (param_val) then -- if the parameter has a value
+
if is_set(param_val) then -- if the parameter has a value
 
if not all and in_array (param_name, {'access-date', 'archive-date'}) then -- if access- or archive-date and format not xxx-all
 
if not all and in_array (param_name, {'access-date', 'archive-date'}) then -- if access- or archive-date and format not xxx-all
 
param_val = ''; -- set to empty string so we don't process this date
 
param_val = ''; -- set to empty string so we don't process this date
 
end
 
end
for source, pattern in pairs (source_patterns) do
+
for source, pattern in pairs(source_patterns) do
if param_val:match (pattern) then
+
if param_val:match(pattern) then
 
if 'ymd' == source then
 
if 'ymd' == source then
 
get_ymd_date_parts (param_val, source_date); -- get the date parts into the source_date table
 
get_ymd_date_parts (param_val, source_date); -- get the date parts into the source_date table
Line 764: Line 750:
 
format_str = long_formats[format];
 
format_str = long_formats[format];
 
end
 
end
-- convert date and save;
+
date_parameters_list[param_name] = mw.text.trim (os.date (format_str, os.time(source_date))); -- strip leading space when single digit day and %e is first format
+
date_parameters_list[param_name] = os.date (format_str, os.time(source_date)); -- convert date and save
 
end
 
end
 
end
 
end
Line 772: Line 758:
 
return true; -- declare success and done
 
return true; -- declare success and done
 
end
 
end
 
 
--[[--------------------------< D A T E _ H Y P H E N _ T O _ D A S H >----------------------------------------
 
 
Loops through the list of date-holding parameters and converts any hyphen to an ndash.  Not called if the cs1|2
 
template has any date errors.
 
 
Modifies the date_parameters_list and returns true if hyphens are replaced, else returns false.
 
 
]]
 
 
local function date_hyphen_to_dash (date_parameters_list)
 
local result = false;
 
local n;
 
for param_name, param_val in pairs(date_parameters_list) do -- for each date-holding parameter in the list
 
if not param_val:match ('%d%d%d%d%-%d%d%-%d%d') then -- for those that are not ymd dates
 
param_val, n = param_val:gsub ('%-', '–'); -- replace any hyphen with ndash
 
if 0 ~= n then
 
date_parameters_list[param_name] = param_val; -- update the list
 
result = true;
 
end
 
end
 
end
 
return result; -- so we know if any hyphens were replaced
 
end
 
 
 
--[[-------------------------< D A T E _ N A M E _ X L A T E >------------------------------------------------
 
 
Attempts to translate English month names to local-language month names using names supplied by MediaWiki's
 
date parser function.  This is simple name-for-name replacement and may not work for all languages.
 
 
]]
 
 
local function date_name_xlate (date_parameters_list)
 
local xlate;
 
local mode; -- long or short month names
 
local modified = false;
 
local date;
 
 
for param_name, param_val in pairs(date_parameters_list) do -- for each date-holding parameter in the list
 
if is_set(param_val) then -- if the parameter has a value
 
date = param_val;
 
for month in mw.ustring.gmatch (date, '%a+') do -- iterate through all dates in the date (single date or date range)
 
if cfg.date_names.en.long[month] then
 
mode = 'F'; -- English name is long so use long local name
 
elseif cfg.date_names.en.short[month] then
 
mode = 'M'; -- English name is short so use short local name
 
else
 
mode = nil; -- not an English month name; could be local language month name or an English season name
 
end
 
 
if mode then -- might be a season
 
xlate = mw.getContentLanguage():formatDate(mode, '1' .. month); -- translate the month name to this local language
 
date = mw.ustring.gsub (date, month, xlate); -- replace the English with the translation
 
date_parameters_list[param_name] = date; -- save the translated date
 
modified = true;
 
end
 
end
 
 
end
 
end
 
 
return modified;
 
end
 
  
  
Line 845: Line 766:
 
]]
 
]]
  
local function set_selected_modules (cfg_table_ptr, utilities_page_ptr)
+
local function set_selected_modules (utilities_page_ptr)
is_set = utilities_page_ptr.is_set; -- import functions from selected Module:Citation/CS1/Utilities module
+
is_set = utilities_page_ptr.is_set; -- import functions from select Module:Citation/CS1/Utilities module
in_array = utilities_page_ptr.in_array; -- import functions from selected Module:Citation/CS1/Utilities module
+
in_array = utilities_page_ptr.in_array; -- import functions from select Module:Citation/CS1/Utilities module
cfg = cfg_table_ptr; -- import tables from selected Module:Citation/CS1/Configuration
 
 
end
 
end
  
Line 857: Line 777:
 
year_date_check = year_date_check,
 
year_date_check = year_date_check,
 
reformat_dates = reformat_dates,
 
reformat_dates = reformat_dates,
date_hyphen_to_dash = date_hyphen_to_dash,
 
date_name_xlate = date_name_xlate,
 
 
set_selected_modules = set_selected_modules
 
set_selected_modules = set_selected_modules
 
}
 
}

Latest revision as of 19:58, 31 January 2018

{{#lst:Module:Citation/CS1/doc|header}}

This module contains routines that support the Citation Style 1 and Citation Style 2 date formats for citations on Wikipedia. In particular, this module contains a suite of functions that validate date formats and content for the variety of date-holding parameters associated with cs1|2 citations.

{{#lst:Module:Citation/CS1/doc|module_components_table}}



local p = {}


--[[--------------------------< F O R W A R D   D E C L A R A T I O N S >--------------------------------------
]]

local is_set, in_array;																	-- imported function from selected Module:Citation/CS1/Utilities


--[=[-------------------------< I S _ V A L I D _ A C C E S S D A T E >----------------------------------------

returns true if:
	Wikipedia start date <= accessdate < today + 2 days

Wikipedia start date is 2001-01-15T00:00:00 UTC which is 979516800 seconds after 1970-01-01T00:00:00 UTC (the start of Unix time)
accessdate is the date provided in |accessdate= at time 00:00:00 UTC
today is the current date at time 00:00:00 UTC plus 48 hours
	if today is 2015-01-01T00:00:00 then
		adding 24 hours gives 2015-01-02T00:00:00 – one second more than today
		adding 24 hours gives 2015-01-03T00:00:00 – one second more than tomorrow

This function does not work for languages other than English.  Wikimedia #time: parser apparently doesn't understand
non-Engish date month names. This function will always return false when the date contains a non-English month name
because good1 is false after the call to lang.formatDate.

For the time being, to use this function, supply it with YYYY-MM-DD format dates.  See
[[bs:Modul:Citation/CS1/Date validation/igralište]] for one possible solution.

]=]

local function is_valid_accessdate (accessdate)
	local lang = mw.getContentLanguage();
	local good1, good2;
	local access_ts, tomorrow_ts;												-- to hold unix time stamps representing the dates
		
	good1, access_ts = pcall( lang.formatDate, lang, 'U', accessdate );			-- convert accessdate value to unix timesatmp 
	good2, tomorrow_ts = pcall( lang.formatDate, lang, 'U', 'today + 2 days' );	-- today midnight + 2 days is one second more than all day tomorrow
	
	if good1 and good2 then
		access_ts = tonumber (access_ts);										-- convert to numbers for the comparison
		tomorrow_ts = tonumber (tomorrow_ts);
	else
		return false;															-- one or both failed to convert to unix time stamp
	end
	
	if 979516800 <= access_ts and access_ts < tomorrow_ts then					-- Wikipedia start date <= accessdate < tomorrow's date
		return true;
	else
		return false;															-- accessdate out of range
	end
end


--[[--------------------------< G E T _ M O N T H _ N U M B E R >----------------------------------------------

returns a number according to the month in a date: 1 for January, etc.  Capitalization and spelling must be correct. If not a valid month, returns 0

]]

local function get_month_number (month)
local long_months = {['January']=1, ['February']=2, ['March']=3, ['April']=4, ['May']=5, ['June']=6, ['July']=7, ['August']=8, ['September']=9, ['October']=10, ['November']=11, ['December']=12};
local short_months = {['Jan']=1, ['Feb']=2, ['Mar']=3, ['Apr']=4, ['May']=5, ['Jun']=6, ['Jul']=7, ['Aug']=8, ['Sep']=9, ['Oct']=10, ['Nov']=11, ['Dec']=12};
	return long_months[month] or												-- if month is the long-form name
		short_months[month] or													-- if month is the short-form name
		0;																		-- misspelled, improper case, or not a month name
end


--[[--------------------------< I S _ V A L I D _ E M B A R G O _ D A T E >------------------------------------

returns true and date value if that value has proper dmy, mdy, ymd format.

returns false and 9999 when date value is not proper format; assumes that when |embargo= is set, the editor
intended to embargo a pmc but |embargo does not hold a single date.

]]

local function is_valid_embargo_date (v)
	if v:match ('^%d%d%d%d%-%d%d%-%d%d$') or									-- ymd
		v:match ('^%d%d?%s+%a+%s+%d%d%d%d$') or									-- dmy
		v:match ('^%a+%s+%d%d?%s*,%s*%d%d%d%d$') then							-- mdy
			return true, v;
	end
	return false, '9999';														-- if here not good date so return false and set embargo date to long time in future
end


--[[--------------------------< G E T _ S E A S O N _ N U M B E R >--------------------------------------------

returns a number according to the sequence of seasons in a year: 1 for Winter, etc.  Capitalization and spelling must be correct. If not a valid season, returns 0

]]

local function get_season_number (season)
local season_list = {['Winter']=21, ['Spring']=22, ['Summer']=23, ['Fall']=24, ['Autumn']=24};	-- make sure these numbers do not overlap month numbers
local temp;
	temp=season_list[season];
	if temp then return temp; end												-- if season is a valid name return its number
	return 0;																	-- misspelled, improper case, or not a season name
end

--[[--------------------------< I S _ P R O P E R _ N A M E >--------------------------------------------------

returns a non-zero number if date contains a recognized proper name.  Capitalization and spelling must be correct.

]]

local function is_proper_name (name)
local name_list = {['Christmas']=31}
local temp;
	temp=name_list[name];
	if temp then return temp; end				-- if name is a valid name return its number
	return 0;									-- misspelled, improper case, or not a proper name
end

--[[--------------------------< I S _ V A L I D _ M O N T H _ O R _ S E A S O N >------------------------------

--returns true if month or season is valid (properly spelled, capitalized, abbreviated)

]]

local function is_valid_month_or_season (month_season)
	if 0 == get_month_number (month_season) then		-- if month text isn't one of the twelve months, might be a season
		if 0 == get_season_number (month_season) then	-- not a month, is it a season?
			return false;								-- return false not a month or one of the five seasons
		end
	end
	return true;
end

--[[--------------------------< I S _ V A L I D _ Y E A R >----------------------------------------------------

Function gets current year from the server and compares it to year from a citation parameter.  Years more than one year in the future are not acceptable.

]]
local year_limit;
local function is_valid_year(year)
	if not is_set(year_limit) then
		year_limit = tonumber(os.date("%Y"))+1;			-- global variable so we only have to fetch it once
	end
	return tonumber(year) <= year_limit;				-- false if year is in the future more than one year
end

--[[--------------------------< I S _ V A L I D _ D A T E >----------------------------------------------------
Returns true if day is less than or equal to the number of days in month and year is no farther into the future
than next year; else returns false.

Assumes Julian calendar prior to year 1582 and Gregorian calendar thereafter. Accounts for Julian calendar leap
years before 1582 and Gregorian leap years after 1582. Where the two calendars overlap (1582 to approximately
1923) dates are assumed to be Gregorian.

]]

local function is_valid_date (year, month, day)
local days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
local month_length;
	if not is_valid_year(year) then												-- no farther into the future than next year
		return false;
	end
	
	month = tonumber(month);													-- required for YYYY-MM-DD dates
	
	if (2==month) then															-- if February
		month_length = 28;														-- then 28 days unless
		if 1582 > tonumber(year) then											-- Julian calendar
			if 0==(year%4) then
				month_length = 29;
			end
		else																	-- Gregorian calendar
			if (0==(year%4) and (0~=(year%100) or 0==(year%400))) then			-- is a leap year?
				month_length = 29;												-- if leap year then 29 days in February
			end
		end
	else
		month_length=days_in_month[month];
	end

	if tonumber (day) > month_length then
		return false;
	end
	return true;
end

--[[--------------------------< I S _ V A L I D _ M O N T H _ R A N G E _ S T Y L E >--------------------------

Months in a range are expected to have the same style: Jan–Mar or October–December but not February–Mar or Jul–August. 
There is a special test for May because it can be either short or long form.

Returns true when style for both months is the same

]]

local function is_valid_month_range_style (month1, month2)
local len1 = month1:len();
local len2 = month2:len();
	if len1 == len2 then
		return true;															-- both months are short form so return true
	elseif 'May' == month1 or 'May'== month2 then
		return true;															-- both months are long form so return true
	elseif 3 == len1 or 3 == len2 then
		return false;															-- months are mixed form so return false
	else
		return true;															-- both months are long form so return true
	end
end


--[[--------------------------< I S _ V A L I D _ M O N T H _ S E A S O N _ R A N G E >------------------------

Check a pair of months or seasons to see if both are valid members of a month or season pair.

Month pairs are expected to be left to right, earliest to latest in time.

Similarly, seasons are also left to right, earliest to latest in time.  There is an oddity with seasons: winter is assigned a value of 1, spring 2, ...,
fall and autumn 4.  Because winter can follow fall/autumn at the end of a calender year, a special test is made to see if |date=Fall-Winter yyyy (4-1) is the date.

]]

local function is_valid_month_season_range(range_start, range_end)
	local range_start_number = get_month_number (range_start);
	local range_end_number;
	
	if 0 == range_start_number then												-- is this a month range?
		local range_start_number = get_season_number (range_start);				-- not a month; is it a season? get start season number
		range_end_number = get_season_number (range_end);						-- get end season number

		if 0 ~= range_start_number then											-- is start of range a season?
			if range_start_number < range_end_number then						-- range_start is a season
				return true;													-- return true when range_end is also a season and follows start season; else false
			end
			if 24 == range_start_number and 21 == range_end_number then			-- special case when season range is Fall-Winter or Autumn-Winter
				return true;
			end
		end
		return false;		-- range_start is not a month or a season; or range_start is a season and range_end is not; or improper season sequence
	end

	range_end_number = get_month_number (range_end);							-- get end month number
	if range_start_number < range_end_number then								-- range_start is a month; does range_start precede range_end?
		if is_valid_month_range_style (range_start, range_end) then				-- do months have the same style?
			return true;														-- proper order and same style
		end
	end
	return false;																-- range_start month number is greater than or equal to range end number; or range end isn't a month
end


--[[--------------------------< M A K E _ C O I N S _ D A T E >------------------------------------------------

This function receives a table of date parts for one or two dates and an empty table reference declared in
Module:Citation/CS1.  The function is called only for |date= parameters and only if the |date=<value> is 
determined to be a valid date format.  The question of what to do with invalid date formats is not answered here.

The date parts in the input table are converted to an ISO 8601 conforming date string:
	single whole dates:		yyyy-mm-dd
	month and year dates:	yyyy-mm
	year dates:				yyyy
	ranges:					yyyy-mm-dd/yyyy-mm-dd
							yyyy-mm/yyyy-mm
							yyyy/yyyy

Dates in the Julian calendar are reduced to year or year/year so that we don't have to do calendar conversion from
Julian to Proleptic Gregorian.

The input table has:
	year, year2 – always present; if before 1582, ignore months and days if present
	month, month2 – 0 if not provided, 1-12 for months, 21-24 for seasons; 31– proper name dates
	day, day2 –  0 if not provided, 1-31 for days
	
the output table receives:
	rftdate:	an IS8601 formatted date
	rftchron:	a free-form version of the date, usually without year which is in rftdate (season ranges and propername dates)
	rftssn:		one of four season keywords: winter, spring, summer, fall (lowercase)

]]

local function make_COinS_date (input, tCOinS_date)
	local date;																	-- one date or first date in a range
	local date2 = '';															-- end of range date
	
	if 1582 > tonumber(input.year) or 20 < tonumber(input.month) then			-- Julian calendar or season so &rft.date gets year only
		date = input.year;
		if 0 ~= input.year2 and input.year ~= input.year2 then					-- if a range, only the second year portion when not the same as range start year
			date = string.format ('%.4d/%.4d', tonumber(input.year), tonumber(input.year2))		-- assemble the date range
		end
		if 20 < tonumber(input.month) then										-- if season or propername date
			local season = {[21]='winter', [22]='spring', [23]='summer', [24]='fall', [31]='Christmas'};	-- seasons lowercase, no autumn; proper names use title case
			if 0 == input.month2 then											-- single season date
				if 30 <tonumber(input.month) then
					tCOinS_date.rftchron = season[input.month];					-- proper name dates
				else
					tCOinS_date.rftssn = season[input.month];					-- seasons
				end
			else																-- season range with a second season specified
				if input.year ~= input.year2 then								-- season year – season year range or season year–year
					tCOinS_date.rftssn = season[input.month];					-- start of range season; keep this?
					if 0~= input.month2 then
						tCOinS_date.rftchron = string.format ('%s %s – %s %s', season[input.month], input.year, season[input.month2], input.year2);
					end
				else															-- season–season year range
					tCOinS_date.rftssn = season[input.month];					-- start of range season; keep this?
					tCOinS_date.rftchron = season[input.month] .. '–' .. season[input.month2];	-- season–season year range
				end
			end
		end
		tCOinS_date.rftdate = date;
		return;																	-- done
	end
	
	if 0 ~= input.day then
		date = string.format ('%s-%.2d-%.2d', input.year, tonumber(input.month), tonumber(input.day));	-- whole date
	elseif 0 ~= input.month then
		date = string.format ('%s-%.2d', input.year, tonumber(input.month));	-- year and month
	else
		date = string.format ('%s', input.year);								-- just year
	end

	if 0 ~= input.year2 then
		if 0 ~= input.day2 then
			date2 = string.format ('/%s-%.2d-%.2d', input.year2, tonumber(input.month2), tonumber(input.day2));		-- whole date
		elseif 0 ~= input.month2 then
			date2 = string.format ('/%s-%.2d', input.year2, tonumber(input.month2));	-- year and month
		else
			date2 = string.format ('/%s', input.year2);							-- just year
		end
	end
	
	tCOinS_date.rftdate = date .. date2;										-- date2 has the '/' separator
	return;
end


--[[--------------------------< C H E C K _ D A T E >----------------------------------------------------------

Check date format to see that it is one of the formats approved by WP:DATESNO or WP:DATERANGE. Exception: only
allowed range separator is endash.  Additionally, check the date to see that it is a real date: no 31 in 30-day
months; no 29 February when not a leap year.  Months, both long-form and three character abbreviations, and seasons
must be spelled correctly.  Future years beyond next year are not allowed.

If the date fails the format tests, this function returns false and does not return values for anchor_year and
COinS_date.  When this happens, the date parameter is used in the COinS metadata and the CITEREF identifier gets
its year from the year parameter if present otherwise CITEREF does not get a date value.

Inputs:
	date_string - date string from date-holding parameters (date, year, accessdate, embargo, archivedate, etc.)

Returns:
	false if date string is not a real date; else
	true, anchor_year, COinS_date
		anchor_year can be used in CITEREF anchors
		COinS_date is ISO 8601 format date; see make_COInS_date()

]]

local function check_date (date_string, tCOinS_date)
	local year;			-- assume that year2, months, and days are not used;
	local year2=0;		-- second year in a year range
	local month=0;
	local month2=0;		-- second month in a month range
	local day=0;
	local day2=0;		-- second day in a day range
	local anchor_year;
	local coins_date;

	if date_string:match("^%d%d%d%d%-%d%d%-%d%d$") then										-- year-initial numerical year month day format
		year, month, day=string.match(date_string, "(%d%d%d%d)%-(%d%d)%-(%d%d)");
		if 12 < tonumber(month) or 1 > tonumber(month) or 1582 > tonumber(year) or 0 == tonumber(day) then return false; end	-- month or day number not valid or not Gregorian calendar
		anchor_year = year;

	elseif date_string:match("^%a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then						-- month-initial: month day, year
		month, day, anchor_year, year=string.match(date_string, "(%a+)%s*(%d%d?),%s*((%d%d%d%d)%a?)");
		month = get_month_number (month);
		if 0 == month then return false; end												-- return false if month text isn't one of the twelve months
				
	elseif date_string:match("^%a+ +[1-9]%d?–[1-9]%d?, +[1-9]%d%d%d%a?$") then				-- month-initial day range: month day–day, year; days are separated by endash
		month, day, day2, anchor_year, year=string.match(date_string, "(%a+) +(%d%d?)–(%d%d?), +((%d%d%d%d)%a?)");
		if tonumber(day) >= tonumber(day2) then return false; end							-- date range order is left to right: earlier to later; dates may not be the same;
		month = get_month_number (month);
		if 0 == month then return false; end												-- return false if month text isn't one of the twelve months
		month2=month;																		-- for metadata
		year2=year;

	elseif date_string:match("^[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then						-- day-initial: day month year
		day, month, anchor_year, year=string.match(date_string, "(%d%d*)%s*(%a+)%s*((%d%d%d%d)%a?)");
		month = get_month_number (month);
		if 0 == month then return false; end												-- return false if month text isn't one of the twelve months

	elseif date_string:match("^[1-9]%d?–[1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then				-- day-range-initial: day–day month year; days are separated by endash
		day, day2, month, anchor_year, year=string.match(date_string, "(%d%d?)–(%d%d?) +(%a+) +((%d%d%d%d)%a?)");
		if tonumber(day) >= tonumber(day2) then return false; end							-- date range order is left to right: earlier to later; dates may not be the same;
		month = get_month_number (month);
		if 0 == month then return false; end												-- return false if month text isn't one of the twelve months
		month2=month;																		-- for metadata
		year2=year;

	elseif date_string:match("^[1-9]%d? +%a+ – [1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then		-- day initial month-day-range: day month - day month year; uses spaced endash
		day, month, day2, month2, anchor_year, year=date_string:match("(%d%d?) +(%a+) – (%d%d?) +(%a+) +((%d%d%d%d)%a?)");
		if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end	-- date range order is left to right: earlier to later;
		month = get_month_number (month);													-- for metadata
		month2 = get_month_number (month2);
		year2=year;

	elseif date_string:match("^%a+ +[1-9]%d? – %a+ +[1-9]%d?, +[1-9]%d%d%d?%a?$") then		-- month initial month-day-range: month day – month day, year;  uses spaced endash
		month, day, month2, day2, anchor_year, year=date_string:match("(%a+) +(%d%d?) – (%a+) +(%d%d?), +((%d%d%d%d)%a?)");
		if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end
		month = get_month_number (month);													-- for metadata
		month2 = get_month_number (month2);
		year2=year;

	elseif date_string:match("^[1-9]%d? +%a+ +[1-9]%d%d%d – [1-9]%d? +%a+ +[1-9]%d%d%d%a?$") then		-- day initial month-day-year-range: day month year - day month year; uses spaced endash
		day, month, year, day2, month2, anchor_year, year2=date_string:match("(%d%d?) +(%a+) +(%d%d%d%d?) – (%d%d?) +(%a+) +((%d%d%d%d?)%a?)");
		if tonumber(year2) <= tonumber(year) then return false; end												-- must be sequential years, left to right, earlier to later
		if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end		-- year2 no more than one year in the future; months same style
		month = get_month_number (month);																		-- for metadata
		month2 = get_month_number (month2);

	elseif date_string:match("^%a+ +[1-9]%d?, +[1-9]%d%d%d – %a+ +[1-9]%d?, +[1-9]%d%d%d%a?$") then		-- month initial month-day-year-range: month day, year – month day, year;  uses spaced endash
		month, day, year, month2, day2, anchor_year, year2=date_string:match("(%a+) +(%d%d?), +(%d%d%d%d) – (%a+) +(%d%d?), +((%d%d%d%d)%a?)");
		if tonumber(year2) <= tonumber(year) then return false; end												-- must be sequential years, left to right, earlier to later
		if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end		-- year2 no more than one year in the future; months same style
		month = get_month_number (month);																		-- for metadata
		month2 = get_month_number (month2);

	elseif date_string:match("^%a+ +[1-9]%d%d%d–%d%d%a?$") then								-- special case Winter/Summer year-year (YYYY-YY); year separated with unspaced endash
		local century;
		month, year, century, anchor_year, year2=date_string:match("(%a+) +((%d%d)%d%d)–((%d%d)%a?)");
		if 'Winter' ~= month and 'Summer' ~= month then return false end;					-- 'month' can only be Winter or Summer
		anchor_year=year..'–'..anchor_year;													-- assemble anchor_year from both years
		year2 = century..year2;																-- add the century to year2 for comparisons
		if 1 ~= tonumber(year2) - tonumber(year) then return false; end						-- must be sequential years, left to right, earlier to later
		if not is_valid_year(year2) then return false; end									-- no year farther in the future than next year
		month = get_season_number (month);

	elseif date_string:match("^%a+ +[1-9]%d%d%d–[1-9]%d%d%d%a?$") then						-- special case Winter/Summer year-year; year separated with unspaced endash
		month, year, anchor_year, year2=date_string:match("(%a+) +(%d%d%d%d)–((%d%d%d%d)%a?)");
		if 'Winter' ~= month and 'Summer' ~= month then return false end;					-- 'month' can only be Winter or Summer
		anchor_year=year..'–'..anchor_year;													-- assemble anchor_year from both years
		if 1 ~= tonumber(year2) - tonumber(year) then return false; end						-- must be sequential years, left to right, earlier to later
		if not is_valid_year(year2) then return false; end									-- no year farther in the future than next year
		month = get_season_number (month);													-- for metadata

	elseif date_string:match("^%a+ +[1-9]%d%d%d% – %a+ +[1-9]%d%d%d%a?$") then				-- month/season year - month/season year; separated by spaced endash
		month, year, month2, anchor_year, year2=date_string:match("(%a+) +(%d%d%d%d) – (%a+) +((%d%d%d%d)%a?)");
		anchor_year=year..'–'..anchor_year;													-- assemble anchor_year from both years
		if tonumber(year) >= tonumber(year2) then return false; end							-- left to right, earlier to later, not the same
		if not is_valid_year(year2) then return false; end									-- no year farther in the future than next year
		if 0 ~= get_month_number(month) and 0 ~= get_month_number(month2) and is_valid_month_range_style(month, month2) then 	-- both must be month year, same month style
			month = get_month_number(month);
			month2 = get_month_number(month2);
		elseif 0 ~= get_season_number(month) and 0 ~= get_season_number(month2) then		-- both must be or season year, not mixed
			month = get_season_number(month);
			month2 = get_season_number(month2);
		else
			 return false;
		end

	elseif date_string:match ("^%a+–%a+ +[1-9]%d%d%d%a?$") then					-- month/season range year; months separated by endash 
		month, month2, anchor_year, year=date_string:match ("(%a+)–(%a+)%s*((%d%d%d%d)%a?)");
		if (not is_valid_month_season_range(month, month2)) or (not is_valid_year(year)) then return false; end
		if 0 ~= get_month_number(month) then									-- determined to be a valid range so just check this one to know if month or season
			month = get_month_number(month);
			month2 = get_month_number(month2);
		else
			month = get_season_number(month);
			month2 = get_season_number(month2);
		end
		year2=year;
		
	elseif date_string:match("^%a+ +%d%d%d%d%a?$") then							-- month/season year or proper-name year
		month, anchor_year, year=date_string:match("(%a+)%s*((%d%d%d%d)%a?)");
		if not is_valid_year(year) then return false; end
		if not is_valid_month_or_season (month) and 0 == is_proper_name (month) then return false; end
		if 0 ~= get_month_number(month) then									-- determined to be a valid range so just check this one to know if month or season
			month = get_month_number(month);
		elseif 0 ~= get_season_number(month) then
			month = get_season_number(month);
		else
			month = is_proper_name (month);										-- must be proper name; not supported in COinS
		end

	elseif date_string:match("^[1-9]%d%d%d?–[1-9]%d%d%d?%a?$") then				-- Year range: YYY-YYY or YYY-YYYY or YYYY–YYYY; separated by unspaced endash; 100-9999
		year, anchor_year, year2=date_string:match("(%d%d%d%d?)–((%d%d%d%d?)%a?)");
		anchor_year=year..'–'..anchor_year;										-- assemble anchor year from both years
		if tonumber(year) >= tonumber(year2) then return false; end				-- left to right, earlier to later, not the same
		if not is_valid_year(year2) then return false; end						-- no year farther in the future than next year

	elseif date_string:match("^[1-9]%d%d%d–%d%d%a?$") then						-- Year range: YYYY–YY; separated by unspaced endash
		local century;
		year, century, anchor_year, year2=date_string:match("((%d%d)%d%d)–((%d%d)%a?)");
		anchor_year=year..'–'..anchor_year;										-- assemble anchor year from both years
		if 13 > tonumber(year2) then return false; end							-- don't allow 2003-05 which might be May 2003
		year2 = century..year2;													-- add the century to year2 for comparisons
		if tonumber(year) >= tonumber(year2) then return false; end				-- left to right, earlier to later, not the same
		if not is_valid_year(year2) then return false; end						-- no year farther in the future than next year

	elseif date_string:match("^[1-9]%d%d%d?%a?$") then							-- year; here accept either YYY or YYYY
		anchor_year, year=date_string:match("((%d%d%d%d?)%a?)");
		if false == is_valid_year(year) then
			return false;
		end

	else
		return false;															-- date format not one of the MOS:DATE approved formats
	end

	local result=true;															-- check whole dates for validity; assume true because not all dates will go through this test
	if 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 == month2 and 0 == day2 then		-- YMD (simple whole date)
		result=is_valid_date(year,month,day);

	elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 == month2 and 0 ~= day2 then	-- YMD-d (day range)
		result=is_valid_date(year,month,day);
		result=result and is_valid_date(year,month,day2);

	elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 ~= month2 and 0 ~= day2 then	-- YMD-md (day month range)
		result=is_valid_date(year,month,day);
		result=result and is_valid_date(year,month2,day2);

	elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 ~= year2 and 0 ~= month2 and 0 ~= day2 then	-- YMD-ymd (day month year range)
		result=is_valid_date(year,month,day);
		result=result and is_valid_date(year2,month2,day2);
	end
	
	if false == result then return false; end

	if nil ~= tCOinS_date then													-- this table only passed into this function when testing |date= parameter values
		make_COinS_date ({year=year, month=month, day=day, year2=year2, month2=month2, day2=day2}, tCOinS_date);	-- make an ISO 8601 date string for COinS
	end
	
	return true, anchor_year;													-- format is good and date string represents a real date
end	


--[[--------------------------< D A T E S >--------------------------------------------------------------------

Cycle the date-holding parameters in passed table date_parameters_list through check_date() to check compliance with MOS:DATE. For all valid dates, check_date() returns
true. The |date= parameter test is unique, it is the only date holding parameter from which values for anchor_year (used in CITEREF identifiers) and COinS_date (used in
the COinS metadata) are derived.  The |date= parameter is the only date-holding parameter that is allowed to contain the no-date keywords "n.d." or "nd" (without quotes).

Unlike most error messages created in this module, only one error message is created by this function. Because all of the date holding parameters are processed serially,
a single error message is created as the dates are tested.

]]

local function dates(date_parameters_list, tCOinS_date)
	local anchor_year;		-- will return as nil if the date being tested is not |date=
	local COinS_date;		-- will return as nil if the date being tested is not |date=
	local embargo_date = '9999';												-- if good dmy, mdy, ymd date then holds original value else 9999
	local error_message = "";
	local good_date = false;
	
	for k, v in pairs(date_parameters_list) do									-- for each date-holding parameter in the list
		if is_set(v) then														-- if the parameter has a value
			if v:match("^c%. [1-9]%d%d%d?%a?$") then							-- special case for c. year or with or without CITEREF disambiguator - only |date= and |year=
				local year = v:match("c%. ([1-9]%d%d%d?)%a?");					-- get the year portion so it can be tested
				if 'date'==k then
					anchor_year, COinS_date = v:match("((c%. [1-9]%d%d%d?)%a?)");	-- anchor year and COinS_date only from |date= parameter
					good_date = is_valid_year(year);
				elseif 'year'==k then
					good_date = is_valid_year(year);
				end
			elseif 'date'==k then												-- if the parameter is |date=
				if v:match("^n%.d%.%a?") then									-- if |date=n.d. with or without a CITEREF disambiguator
					good_date, anchor_year, COinS_date = true, v:match("((n%.d%.)%a?)");	--"n.d."; no error when date parameter is set to no date
				elseif v:match("^nd%a?$") then									-- if |date=nd with or without a CITEREF disambiguator
					good_date, anchor_year, COinS_date = true, v:match("((nd)%a?)");	--"nd";	no error when date parameter is set to no date
				else
					good_date, anchor_year, COinS_date = check_date (v, tCOinS_date);	-- go test the date
				end
			elseif 'access-date'==k then										-- if the parameter is |access-date=
				good_date = check_date (v);										-- go test the date
				if true == good_date then										-- if the date is a valid date
					good_date = is_valid_accessdate (v);						-- is Wikipedia start date < accessdate < tomorrow's date?
				end
			elseif 'embargo'==k then											-- if the parameter is |embargo=
				good_date = check_date (v);										-- go test the date
				if true == good_date then										-- if the date is a valid date
					good_date, embargo_date = is_valid_embargo_date (v);		-- is |embargo= date a single dmy, mdy, or ymd formatted date? yes:returns embargo; no: returns 9999
				end
			else																-- any other date-holding parameter
				good_date = check_date (v);										-- go test the date
			end
			if false==good_date then											-- assemble one error message so we don't add the tracking category multiple times
				if is_set(error_message) then									-- once we've added the first portion of the error message ...
					error_message=error_message .. ", ";						-- ... add a comma space separator
				end
				error_message=error_message .. "&#124;" .. k .. "=";			-- add the failed parameter
			end
		end
	end
	return anchor_year, embargo_date, error_message;											-- and done
end


--[[--------------------------< Y E A R _ D A T E _ C H E C K >------------------------------------------------

Compare the value provided in |year= with the year value(s) provided in |date=.  This function returns a numeric value:
	0 - year value does not match the year value in date
	1 - (default) year value matches the year value in date or one of the year values when date contains two years
	2 - year value matches the year value in date when date is in the form YYYY-MM-DD and year is disambiguated (|year=YYYYx)

]]

local function year_date_check (year_string, date_string)
	local year;
	local date1;
	local date2;
	local result = 1;															-- result of the test; assume that the test passes
	
	year = year_string:match ('(%d%d%d%d?)');

	if date_string:match ('%d%d%d%d%-%d%d%-%d%d') and year_string:match ('%d%d%d%d%a') then	--special case where both date and year are required YYYY-MM-DD and YYYYx
		date1 = date_string:match ('(%d%d%d%d)');
		year = year_string:match ('(%d%d%d%d)');
		if year ~= date1 then
			result = 0;															-- years don't match
		else
			result = 2;															-- years match; but because disambiguated, don't add to maint cat
		end
		
	elseif date_string:match ("%d%d%d%d?.-%d%d%d%d?") then						-- any of the standard range formats of date with two three- or four-digit years
		date1, date2 = date_string:match ("(%d%d%d%d?).-(%d%d%d%d?)");
		if year ~= date1 and year ~= date2 then
			result = 0;
		end

	elseif date_string:match ("%d%d%d%d–%d%d") then								-- YYYY-YY date ranges
		local century;
		date1, century, date2 = date_string:match ("((%d%d)%d%d)[%s%-–]+(%d%d)");
		date2 = century..date2;													-- convert YY to YYYY
		if year ~= date1 and year ~= date2 then
			result = 0;
		end

	elseif date_string:match ("%d%d%d%d?") then									-- any of the standard formats of date with one year
		date1 = date_string:match ("(%d%d%d%d?)");
		if year ~= date1 then
			result = 0;
		end
	else
		result = 0;																-- no recognizable year in date
	end
	return result;
end


--[[-------------------------< R E F O R M A T   T A B L E S >------------------------------------------------

These table are used exclusively for reformatting dates

]]

local source_patterns = {						-- this table holds patterns that match allowed date formats used to extract date components
	['dmy'] = '(%d%d?)%s+(%a+)%s+(%d%d%d%d)',
	['mdy'] = '(%a+)%s+(%d%d?),%s+(%d%d%d%d)',
	['ymd'] = '(%d%d%d%d)%-(%d%d)-(%d%d)',
	}

local short_formats = {							-- this table holds format strings used by os.date() for short month names
	['dmy'] = '%e %b %Y',
	['mdy'] = '%b %e, %Y',
	['ymd'] = '%F',
	}

local long_formats = {							-- this table holds format strings used by os.date() for long month names
	['dmy'] = '%e %B %Y',
	['mdy'] = '%B %e, %Y',
	['ymd'] = '%F',
	}


--[[-------------------------< G E T _ D M Y _ D A T E _ P A R T S >------------------------------------------

extracts year, month and day from DMY formatted date, places them in the source_date table, and returns.

]]

local function get_dmy_date_parts (date, source_date)
	source_date.day, source_date.month, source_date.year = date:match (source_patterns['dmy']);	-- get date components as strings
	source_date.month = get_month_number (source_date.month);					-- get month number
end


--[[-------------------------< G E T _ M D Y _ D A T E _ P A R T S >------------------------------------------

extracts year, month and day from MDY formatted date, places them in the source_date table, and returns.

]]

local function get_mdy_date_parts (date, source_date)
	source_date.month, source_date.day, source_date.year = date:match (source_patterns['mdy']);	-- get date components as strings
	source_date.month = get_month_number (source_date.month);					-- get month number
end


--[[-------------------------< G E T _ Y M D _ D A T E _ P A R T S >------------------------------------------

extracts year, month and day from YMD formatted date, places them in the source_date table, and returns.

]]

local function get_ymd_date_parts (date, source_date)
	source_date.year, source_date.month, source_date.day = date:match (source_patterns['ymd']);	-- get date components as strings
end


--[[-------------------------< R E F O R M A T _ D A T E S >--------------------------------------------------

Reformats existing dates into the format specified by format and short.

format is one of several keywords: dmy, dmy-all, mdy, mdy-all, ymd, ymd-all.  The all version includes access- and
archive-dates; otherwise these dates are not reformatted

Date ranges, season dates, proper name dates are not currently supported.

]]

local function reformat_dates (date_parameters_list, format, short)
	local all = false;															-- set to false to skip access- and archive-dates
	local format_str;
	local source_date = {};
	
	if format:match('%a+%-all') then
		format = format:match('(%a+)%-all');									-- extract the format
		all = true;																-- set to true to format access- and archive-dates
	end
	
	for param_name, param_val in pairs(date_parameters_list) do					-- for each date-holding parameter in the list
		if is_set(param_val) then												-- if the parameter has a value
			if not all and in_array (param_name, {'access-date', 'archive-date'}) then	-- if access- or archive-date and format not xxx-all
				param_val = '';													-- set to empty string so we don't process this date
			end
			for source, pattern in pairs(source_patterns) do
				if param_val:match(pattern) then
					if 'ymd' == source then
						get_ymd_date_parts (param_val, source_date);			-- get the date parts into the source_date table
					elseif 'dmy' == source then
						get_dmy_date_parts (param_val, source_date);			-- get the date parts into the source_date table
					elseif 'mdy' == source then
						get_mdy_date_parts (param_val, source_date);			-- get the date parts into the source_date table
					end

					if 'ymd' == format and 1582 > tonumber(source_date.year) then	-- ymd format dates not allowed before 1582
						return false;											-- abandon reformatting
					end
					
					if short then
						format_str = short_formats[format];
					else
						format_str = long_formats[format];
					end
					
					date_parameters_list[param_name] = os.date (format_str, os.time(source_date));	-- convert date and save
				end
			end
		end
	end
	return true;																-- declare success and done
end


--[[--------------------------< S E T _ S E L E C T E D _ M O D U L E S >--------------------------------------

Sets local imported functions table to same (live or sandbox) as that used by the other modules.

]]

local function set_selected_modules (utilities_page_ptr)
	is_set = utilities_page_ptr.is_set;											-- import functions from select Module:Citation/CS1/Utilities module
	in_array = utilities_page_ptr.in_array;											-- import functions from select Module:Citation/CS1/Utilities module
end



return {																		-- return exported functions
	dates = dates,
	year_date_check = year_date_check,
	reformat_dates = reformat_dates,
	set_selected_modules = set_selected_modules
	}