Module:WikidataCoord

This module accepts, as the first unnamed or positional parameter, a latitude and longitude string in the form returned by Wikidata or as plain-text. The lat/long is stripped of all but its numeric values which are then used in a call to Template:Coord for proper visual rendering and link to GeoHack.

Wikidata returns text strings in this form where the minute and second symbols are html numeric character references for single and double quotes:

{{#property:P625|from=Q218501}}

The module will accept degree-minute-second (dms) plain-text strings in the form:

47°34'12"N, 52°40'55"W

where the minutes and seconds indicators are single and double quotes or single and double prime symbols (′, ″; U+2032, U+2033)

Latitude and longitude in decimal-degree format is also accepted:

53.67667°N 112.82861°W

Because Template:Coord supports a variety of coordinate and template parameters, this module accepts but does not act on these parameter except to pass them on in the call to Template:Coord. In the module {{#invoke:}}, coordinate parameters, if provided, must be the second unnamed or positional parameter. The template parameters are named so their order in the {{#invoke:}} is not important.

Usage

A typical template use where the latitude / longitude is drawn from Wikidata might look like this:

{{#invoke:WikidataCoord|main|{{#property:P625|from={{{1|}}}}}|{{{2|}}}|display={{{display|}}}|format={{{format|}}}|name={{{name|}}}|notes={{{notes|}}}}}

require('Module:No globals')
local getArgs = require('Module:Arguments').getArgs

local patterns = {
	'(%d+)°(%d+)&#39;([%d%.]+)&#34;([NS]),%s*(%d+)°(%d+)&#39;([%d%.]+)&#34;([EW])',		-- if the returned data looks like 55°13&#39;12&#34;N, 23°17&#39;17&#34;E
	'(%d+)°(%d+)&#39;([NS]),%s*(%d+)°(%d+)&#39;([EW])',									-- if the returned data looks like 54°24&#39;N, 25°25&#39;E
	'(%d+)°(%d+)[′\']([%d%.]+)[″\"]([NS]),?%s*(%d+)°(%d+)[′\']([%d%.]+)[″\"]([EW])',	-- when args[1] is a dms string that uses quotes or primes
	'(%d+)°(%d+)[′\']([NS]),?%s*(%d+)°(%d+)[′\']([EW])',								-- when args[1] is a dms string that uses quotes or primes, bit shorter format
	'(%d+%.?%d*)°([NS]),?%s*(%d+%.?%d*)°([EW])',										-- when args[1] is a decimal degrees string
	}

local params = {'display', 'format', 'name', 'notes'};							-- {{coord}} template paramters


--[[--------------------------< I S _ S E T >------------------------------------------------------------------

Whether variable is set or not.  A variable is set when it is not nil and not empty.

]]

local function is_set( var )
	return not (var == nil or var == '');
end


--[[--------------------------< M A I N >----------------------------------------------------------------------

Template entry point.  This function takes up to two unnamed positional parameters:
	1 = coordinate string typically from a call to Wikidata like this: {{#property:P625|from=Q...}}
	2 = coordinate parameters; see Template:Coord
	
Also takes the named parameters |display=, |format=, |name=, |notes= which it passes on to {{coord}}

Reformats the Wikidata coordinate string into unnamed parameters for {{coord}}

{{#invoke:WikidataCoord|main|{{#property:P625|from={{{1}}}}}|{{{2}}}|display={{{display}}}|format={{{format}}}|name={{{name}}}|notes={{{notes}}}}}

]]

local function main (frame)
	local args = getArgs(frame);
	local lat_long = {};														-- table of lat/long coords extracted from wikidata return 
	
	if not is_set (args[1]) then												-- in case wikidata returns nothing (happens when Q... is wrong)
		return '<span style="font-size:100%" class="error">{{WikidataCoord}} – missing coordinate data</span>';		-- error message and quit
	else
		for _, pattern in ipairs (patterns) do
			lat_long[1], lat_long[2], lat_long[3], lat_long[4], lat_long[5], lat_long[6], lat_long[7], lat_long[8] =
				mw.ustring.match (args[1], pattern)
			if lat_long[1] then
				break;
			end
		end
	end

	if not lat_long[1] then
		return '<span style="font-size:100%" class="error">{{WikidataCoord}} – malformed coordinate data</span>';	-- wikidata returned something else
	end
	
	if is_set (args[2]) then													-- coordinate parameters are in second unnammed positional parameter
		table.insert (lat_long, args[2]);										-- add coordinate parameters as next positional parameter after coordnates
	end

	for _, param in ipairs (params) do
		if is_set (args[param]) then
			lat_long[param] = args[param];										-- add the named parameters if they have a value
		end
	end

	if args._debug then
		return table.concat ({'<code style="color:inherit; background:inherit; border:none;">{{coord|', table.concat (lat_long, '|' ), '}}</code>'});
	end
	return frame:expandTemplate ({title = 'coord', args=lat_long});				-- invoke template {{coord}} with wikidata lat/long
end


--[[--------------------------< E X P O R T E D   F U N C T I O N >--------------------------------------------
]]

return {main = main}