Module:Template parameter value
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 | This Lua module is used on approximately 11,300,000 pages, or roughly 18% 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 depends on the following other modules: |
Implements {{Template parameter value}} and {{HasTemplate}}, and can be used from other modules.
Module functions
getParameter
getParameter takes 4 arguments: The page name (string), the template/s (string or table of strings), the parameter (string), and an optional options table. It will return either true and the contents of the requested parameter or false and a reason for failure.
The following options are available:
- template_index: Which occurrence of the template to look for the parameter in. Set to -1 for last occurrence. (default: 1)
- parameter_index: Which occurrence of the parameter to look for (default: 1; only applies when
ignore_subtemplatesis false) - ignore_subtemplates: If parameters should only be searched for in the top-level template, ignoring the parameters in subtemplates (default: false)
- only_subtemplates: If parameters should only be searched for in subtemplates of the top-level template (default: false)
- ignore_blank: Whether or not blank values should count towards
parameter_index(default: false) - treat_as_regex: Whether or not the template string(s) should be treated as a lua regex (default: false)
getTemplate
getTemplate takes 3 arguments: The page name (string), the template/s (string or table of strings), and an optional options table. It will return either true and the text of the requested template or false and a reason for failure.
getTemplate supports the options template_index and treat_as_regex from getParameter.
Helper functions
The module exposes some of the helper functions used (matchAllTemplates, getParameters, and getAllParameters) for convenience. Each function has some comments above it in the code explaining its rough purpose.
Template functions
main implements {{Template parameter value}} and acts as a template wrapper for getParameter.
hasTemplate implements {{HasTemplate}} and somewhat acts as a wrapper for getTemplate (it only provides if the template was found, not the template text itself).
Testcases
Testcases are available at Module talk:Template parameter value/testcases
localp={}localPrepareText=require("Module:Wikitext Parsing").PrepareTextlocalfunctiongetTitle(title)localsuccess,titleObj=pcall(mw.title.new,title)ifsuccessthenreturntitleObjelsereturnnilendend--string.gmatch will check the largest block it can without re-scanning whats inside, but we need whats insidelocalfunctionmatchAllTemplates(str)localmatches={}fortemplateinstring.gmatch(str,"{%b{}}")dotable.insert(matches,template)localinnerContent=string.sub(template,3,-3)for_,subtemplateinnext,matchAllTemplates(innerContent)dotable.insert(matches,subtemplate)endendreturnmatchesend--Forked version of getParameters from [[Module:Transcluder]] with extra features removedlocalfunctionescapeString(str)returnstring.gsub(str,'[%^%$%(%)%.%[%]%*%+%-%?%%]','%%%0')endlocalfunctiongetParameters(template)localparameters,parameterOrder={},{}localparams=string.match(template,'{{[^|}]-|(.*)}}')ifparamsthenlocalcount=0-- Temporarily replace pipes in subtemplates and wikilinks to avoid chaosforsubtemplateinstring.gmatch(params,'{%b{}}')doparams=string.gsub(params,escapeString(subtemplate),string.gsub(subtemplate,".",{["%"]="%%",["|"]="@@:@@",["="]="@@_@@"}))endforwikilinkinstring.gmatch(params,'%[%b[]%]')doparams=string.gsub(params,escapeString(wikilink),string.gsub(wikilink,".",{["%"]="%%",["|"]="@@:@@",["="]="@@_@@"}))endforparameterinmw.text.gsplit(params,'|')dolocalparts=mw.text.split(parameter,'=')localkey=mw.text.trim(parts[1])localvalueif#parts==1thenvalue=keycount=count+1key=tostring(count)elsevalue=mw.text.trim(table.concat(parts,'=',2))endvalue=string.gsub(string.gsub(value,'@@:@@','|'),'@@_@@','=')key=string.gsub(string.gsub(key,'@@:@@','|'),'@@_@@','=')table.insert(parameterOrder,key)parameters[key]=valueendendreturnparameters,parameterOrderend-- Returns a table containing parameters and a table with the order in which each of their values were found.-- Since this considers all subtemplates, a single parameter is expected to have multiple values.-- E.g. {{ABC|X={{DEF|X=Value|Y=Other value}}{{ABC|X=Yes}}|Y=P}}-- Would return {X={"{{DEF|X=Value|Y=Other value}}", "Value", "Yes"}, Y={"Other value", "P"}}localfunctiongetAllParameters(template,ignore_blank,only_subtemplates)localparameterTree=setmetatable({},{__index=function(self,key)rawset(self,key,{})returnrawget(self,key)end})localparams,paramOrder=getParameters(template)for_,keyinipairs(paramOrder)dolocalvalue=params[key]ifnotignore_blankorvalue~=""thenifnotonly_subtemplatesthentable.insert(parameterTree[key],value)--Insert the initial value into the treeendforsubtemplateinstring.gmatch(value,"{%b{}}")do--And now check for subvalueslocalsubparams=getAllParameters(subtemplate,ignore_blank)forsubkey,subsetinnext,subparamsdofor_,subvalueinipairs(subset)dotable.insert(parameterTree[subkey],subvalue)--And add any we find to our treeendendendendendreturnparameterTreeend--Module entry point. Returns a success boolean and either the target template or why it failedfunctionp.getTemplate(page,templates,options)ifnottemplatesthen--Required parametersreturnfalse,"Missing required parameter 'templates'"endoptions=optionsor{}localtemplate_index=tonumber(options.template_index)or1localtreat_as_regex=options.treat_as_regexorfalseiftype(templates)=="string"then-- TODO: Find a good way to allow specifying multiple templates via template invocation-- (Modules can just provide a table so no concerns there)-- Comma splitting is a bad idea (lots of templates have a comma in their name)templates={templates}endlocaltitle=getTitle(page)iftitle==nilthenreturnfalse,"Requested title doesn't exist"endlocalcontent=PrepareText(title:getContent()or"")localfoundTemplates=0localfoundTemplatefor_,templateinnext,matchAllTemplates(content)dofor_,wantedTemplateinpairs(templates)doifnottreat_as_regexthenwantedTemplate=escapeString(wantedTemplate)endlocalfirstLetter=string.sub(wantedTemplate,1,1)localfirstUpper,firstLower=firstLetter:upper(),firstLetter:lower()iffirstUpper~=firstLowerthenwantedTemplate="["..firstUpper..firstLower.."]"..string.sub(wantedTemplate,2)endifstring.match(template,"^{{%s*"..wantedTemplate.."%s*[|}]")thenfoundTemplate=templatefoundTemplates=foundTemplates+1iffoundTemplates==template_indexthen--Found our wanted templatereturntrue,foundTemplateendendendendiffoundTemplates>0andtemplate_index==-1thenreturntrue,foundTemplateendreturnfalse,"No valid template found"end--Module entry point. Returns a success boolean and either the target parameter's value or why it failedfunctionp.getParameter(page,templates,parameter,options)ifnot(templatesandparameter)then--Required parametersreturnfalse,"Missing required parameters 'templates' and 'parameter'"endparameter=tostring(parameter)--Force consistencyoptions=optionsor{}localsuccess,text=p.getTemplate(page,templates,options)ifnotsuccessthenreturnsuccess,textelselocalparameter_index=tonumber(options.parameter_index)or1localignore_subtemplates=options.ignore_subtemplatesorfalselocalonly_subtemplates=options.only_subtemplatesorfalselocalignore_blank=options.ignore_blankorfalselocalvalueifignore_subtemplatesthenvalue=getParameters(text)[parameter]or""elselocalparams=getAllParameters(text,ignore_blank,only_subtemplates)value=params[parameter][parameter_index]or""endvalue=string.gsub(value,"</?%a*include%a*>","")value=mw.text.trim(value)--technically wrong in some cases but not a big issuereturntrue,mw.text.decode(value)--decode due to PrepareTextendend--Template entry point. Returns either "yes" or nothing depending on if the wanted template is found--Will return error text if no template is providedfunctionp.hasTemplate(frame)localargs=require('Module:Arguments').getArgs(frame)localyesno=require("Module:Yesno")localpage=args[1]orargs.pagelocaltemplate=args[2]orargs.templatelocaltemplate_index=tonumber(args[3]orargs.N)or1ifnottemplateortemplate==""thenreturn'<span class="error">No template provided for hasTemplate</span>'endlocalfollow=yesno(args.follow)orfalseiffollowthenpage=require("Module:Redirect").luaMain(page)endlocaloptions={template_index=template_index,treat_as_regex=yesno(args.treat_as_regex)orfalse,}localsuccess,_=p.getTemplate(page,template,options)returnsuccessand"yes"or""end--Template entry point for getParameter. Returns an empty string upon failurefunctionp.main(frame)localargs=require('Module:Arguments').getArgs(frame,{wrappers='Template:Template parameter value'})localyesno=require("Module:Yesno")localoptions={template_index=args[3]orargs.template_index,parameter_index=args[5]orargs.parameter_index,ignore_subtemplates=yesno(args.ignore_subtemplatesorargs.ist)orfalse,only_subtemplates=yesno(args.only_subtemplates)orfalse,ignore_blank=yesno(args.ignore_blank)orfalse,treat_as_regex=yesno(args.treat_as_regex)orfalse,}localpage=args[1]orargs.pagelocaltemplate=args[2]orargs.templatelocalparameter=args[4]orargs.parameterlocalsuccess,result=p.getParameter(page,template,parameter,options)ifnotsuccessthenreturn""elseifargs.dontprocessthenreturnresultelsereturnframe:preprocess(result)endendend--Backwards compatabilityp.getValue=p.getParameter--Potentially useful module entry pointsp.matchAllTemplates=matchAllTemplatesp.getParameters=getParametersp.getAllParameters=getAllParametersreturnp