Module:CountryData
.svg/60px-Test_Template_Info-Icon_-_Version_(2).svg.png){kind=icon}
 | This module is rated as ready for general use. It has reached a mature form and is thought to be relatively bug-free and ready for use wherever appropriate. It is ready to mention on help pages and other Wikipedia resources as an option for new users to learn. To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing. |
 | This module is subject to page protection. It is a highly visible module in use by a very large number of pages, or is substituted very frequently. Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is protected from editing. |
 | This Lua module is used on approximately 424,000 pages, or roughly 1% of all pages. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them. |
This module has three functions to extract data from country data templates (which are used for most flag templates).
gettable
Extracts all parameters from a data template and returns them as a Lua table. This function is only usable from other Lua modules; invoke it using require('Module:CountryData').gettable(parameters).
The first parameter is the frame of the invoking module; the second is the country or other entity to get the data of. The optional third parameter is a table of parameters to pass into the data template; this may, for example, include |age= or |mw=, which are used in the values of some sports alias parameters. E.g.,
localdata=require('Module:CountryData').gettable(frame,"France",{age="20",mw="men's"})The function returns an empty table if a data template does not exist or does not conform to the standard structure.
getalias
If used from wikicode, this function returns the value of a single field in a data template. The first parameter is the country or other entity whose data to return; the second is the name of the field. For example, {{#invoke:CountryData|getalias|France|flag alias}} → Flag of France.svg. The other parameters are |variant= to return a variant parameter value, with fallback to the main field value if the variant does not exist, and |def= for the fallback output if the wanted data template or field does not exist, the default for which is a literal "nil".
Note: This is likely not quicker than wikicode-only alternatives such as {{getalias}} and {{getalias2}}, because it transcludes the data template from Lua and converts it to a Lua table using the above function, picks the wanted parameter name, and returns it to wikicode, whereas other templates perform two simple non-Lua transclusions to get, in most cases, the same result. The Lua version does have the advantage that using it with a non-existing country data template returns "nil" (or the value of |def=) rather than a redlink to the data template. See a comparison of the four at User:SiBr4/Flagg tests#Lua-based getalias.
gettemplate
This function concatenates the fields of a data template into a string similar to what you get when transcluding it directly. It can be compared with a direct transclusion to test if a template is being converted to Lua correctly:
{{#tag:pre|{{Country data France}}}} {{#tag:pre|{{#invoke:CountryData|gettemplate|France}}}} gives
{{ {{{1}}} | alias = France | flag alias = Flag of France.svg | flag alias-1790 = Flag of France (1790–1794).svg | flag alias-1794 = Flag of France (1794–1815, 1830–1958).svg | flag alias-1814 = Flag of the Kingdom of France (1814-1830).svg | flag alias-1830 = Flag of France (1794–1815, 1830–1958).svg | flag alias-1848 = Drapeau france 1848.svg | flag alias-1848a = Drapeau france 1848.svg | flag alias-1848b = Flag of France (1794–1815, 1830–1958).svg | flag alias-1974 = Flag of France (lighter variant).svg | flag alias-naval = Civil and Naval Ensign of France.svg | flag alias-naval-1790 = Flag of French-Navy-Revolution.svg | flag alias-air force = Flag of France.svg | link alias-air force = French Air and Space Force | flag alias-coast guard = French Maritime Gendarmerie racing stripe.svg | border-coast guard = | link alias-coast guard = French Maritime Gendarmerie | flag alias-army = Flag of France.svg | link alias-army = French Army | link alias-naval = French Navy | flag alias-navy = Civil and Naval Ensign of France.svg | link alias-navy = French Navy | size = | name = | altlink = | variant = }}{{ {{{1}}} | altlink = | flag alias-naval-1790 = Flag of French-Navy-Revolution.svg | link alias-coast guard = French Maritime Gendarmerie | border-coast guard = | flag alias-1848 = Drapeau france 1848.svg | flag alias = Flag of France.svg | variant = | flag alias-1814 = Flag of the Kingdom of France (1814-1830).svg | flag alias-1830 = Flag of France (1794–1815, 1830–1958).svg | alias = France | flag alias-1794 = Flag of France (1794–1815, 1830–1958).svg | flag alias-army = Flag of France.svg | flag alias-naval = Civil and Naval Ensign of France.svg | flag alias-navy = Civil and Naval Ensign of France.svg | flag alias-1848b = Flag of France (1794–1815, 1830–1958).svg | name = | size = | flag alias-1848a = Drapeau france 1848.svg | link alias-naval = French Navy | flag alias-1974 = Flag of France (lighter variant).svg | link alias-air force = French Air and Space Force | link alias-army = French Army | flag alias-coast guard = French Maritime Gendarmerie racing stripe.svg | flag alias-1790 = Flag of France (1790–1794).svg | flag alias-air force = Flag of France.svg | link alias-navy = French Navy }}Note that, like with all Lua tables, the order of entries is not preserved, so the parameters are mixed up.
localp={}localmostUsed=mw.loadData('Module:CountryData/summary')localfunctiongetcontents(frame,country,params)returnframe:expandTemplate({title="Country data "..country;args=params})endfunctionp.getcachedtable(frame,country,params)country=mostUsed.redirects[country]orcountryifparamsandnext(params)thenreturnp.gettable(frame,country,params)end-- Uses mw.loadData to cache data for the most-used templatesifmostUsed.pages[country]thenlocalcache=mw.loadData('Module:CountryData/cache'..mostUsed.pages[country])ifcache.data[country]thenreturncache.data[country]endend-- if not in cachereturnp.gettable(frame,country,params)endfunctionp.gettable(frame,country,params)--Returns the parameters of a country data template as a Lua table--If not a valid data template, return empty tablelocalbool,s=pcall(getcontents,frame,country,paramsor{})ifbooland(string.find(s,"^%{%{ *%{%{%{1")orstring.find(s,"^%{%{safesubst: *%{%{%{1"))then--Replace parameter delimiters with arbitrary control characters--to avoid clashes if param values contain equals/pipe signss=string.gsub(s,"|([^|=]-)=","\1\1%1\2")s=string.gsub(s,"}}%s*$","\1")--Loop over string and add params to tablelocalpart={}forparinstring.gmatch(s,"\1[^\1\2]-\2[^\1\2]-\1")dolocalk=string.match(par,"\1%s*(.-)%s*\2")localv=string.match(par,"\2%s*(.-)%s*\1")ifvandnot(v==""andstring.find(k,"^flag alias"))thenpart[k]=vendendreturnpartelsereturn{}endendfunctionp.getalias(frame)--Returns a single parameter value from a data templatelocalpart=p.gettable(frame,frame.args[1])ifframe.args.variantthenreturntostring(part[frame.args[2].."-"..frame.args.variant]orpart[frame.args[2]]orframe.args.def)elsereturntostring(part[frame.args[2]]orframe.args.def)endendfunctionp.gettemplate(frame)--For testing, recreates the country data from the created Lua table--Get data tablelocaldata=p.gettable(frame,frame.args[1])--Concatenate fields into a template-like stringlocalout="{{ {{{1}}}"fork,vinpairs(data)doout=out.."\n| "..k.." = "..vendreturnout.."\n}}"endreturnp