יחידה:ParamValidator

This module is based on idea and original code of User:IKhitron.
the source of this module is in //he.wikipedia.org/wiki/Module:ParamValidator

This module exports two functions: calculateViolations( frame, subpages ), and validateParams( frame ).

calculateViolations( frame, subpages ) finds templatedata, in template page or in one of its subpages in the list, if provided. it returns a table with the violations. if there are none, the table is empty. otherwise it has the structure

{
	violation1 = { param1 = value1, param2 = value2 },
	violation2 = { ... },
	...
}

violation1, violation2 etc. are one of the names of specific violations, as described below. param1, param2 etc. are either the names of parameter passed to the template, or defined in templatedata. value1, value2 etc. are the values passed to the template, or an empty string if no such parameter was passed.

the different violations are as follow:

• no-templatedata
  no valid tempaltedata was found in tempalte page, or documentation subpage
• undeclared
  named parameters with non-empty value, does not exist in templatedata
• empty-undeclared
  named parameters with empty value, does not exist in templatedata
• undeclared-numeric
  numeric parameters with non-empty value, does not exist in templatedata
• empty-undeclared-numeric
  numeric parameters with empty value, does not exist in templatedata
• deprecated
  parameters with non-empty value, marked as "deprecated" in tempaltedata
• empty-deprecated
  parameters with empty value, marked as "deprecated" in tempaltedata
• empty-required
  missing or empty parameter marked as "required" in tempaltedata
• incompatible
  a non-empty parameter passed to the template, incompatible with the parameter type defined in templatedata

The second function, validateParams( frame ), can be called from the tempalte' using #invoke. it expects a parameter named "options", which contains the definition of the output. typically, it's used by placing something like so:

<includeonly>{{#invoke:ParamValidator | validateParams | options = {{PV default options}} }}</includeonly>

at the top of the template (be mindful not to add extra spaces and newlines to the template).

the options parameter should be a JSON-encoded string, defining the output, and some special behaviors. the example above assumes that a wiki page named Template:PV default options exists, and contains valid JSON string. for each of the violations defined above, "options" may define an output string, so basically, "options" looks like so:

{
	violation1: outputstring1,
	violation2: outputstring2,
	.... ,
	behavior1: some value,
	....
}

not all violations have to be defined. a violation not defined in "options" will be ignored.

when invoked, it extract "subpages" from the options parameter, and calls:

• calculateViolations( frame, subpages )

if the returned table is empty, no violation were found, and an empty string is returned and nothing else happens.

otherwise, for each of the violations, i.e., the keys of the returned table, when "options" contains this key, the corresonding value is appended to the output.

some further processing is done:

1. several tokens are replaced with calculated values. these are described below.
2. some "meta" violations are calculated: when any none-ignored violation occured, the "any" meta-violation is added to the output in the same way, i.e. the string keyed by "any" in the options is appended to output with appropriate substitutions. similarly, "multiple" meta-violation is created when more than one type of non-ignored violations occured.
3. if the output is not empty, a prefix and suffix strings are prepended and appended to it.

these are the tokens and the replacement.

• templatename
  full template name, including namespace.
• tname_naked
  template name without namespace.
• paramname
  comma-separated list of parameters
• paramandvalue
  is replaced by comma-separated list of "name: value" pairs of parameters and values

the first two are applied to the whole output, including the suffux and prefix, and the rest are applied to the individual violations, each with its own list of offending parameters and values.

the rest of the if the value of some keys is null, this error condition will be ignored, and not counted when calculating "any" and "multiple" conditions.

some other optional fields can be passed via options:

• doc-subpage
  can be either a string, or a list (in square bracktes) of strings, indicating subpages of the template that may contain templatedata.
• ignore
  list of patterns. any parameter whose name matches any pattern, will not considered in violation of any of the rules.
• skip-empty-numeric
  if a quoted number, the module will ignore non-declared empty numeric parameters up to this number
• wrapper-prefix
  openning wrapper element of outpot (defaults to <div class = 'paramvalidator-wrapper'>)
• wrapper-suffix
  closing wrapper element of output (defaults to "</div>")

additional option parameters, named options1, options2, etc. can be passed. any entry defined in these options will override the previous value. a typical use may be like so:

typically, this JSON structure will be placed in a separate template, and retrieved for the module-use as shown above.

<includeonly>{{#invoke:ParamValidator | validateParams | options = {{PV default options}} | options1 = {"key":"value"} }}</includeonly>

"key" can override any of the options fields described above.

---

--[[
this unit contains a single function.

it retrieves the template's templatedata, and uses it to validate the parameters passed to the template.
if any violations found, it returns am appropriate string. this string will typically include some maintenance category, and/or error message.
the operation of the module is controlled by a single parameter passed to it. this string should be valid JSON describing the actions.
the fields of this structure has the following keys, with string or null value:

	* "no-templatedata": no valid tempaltedata was found in tempalte page, or documentation subpage 
	* "undeclared": parameters with non-empty value, which do not exist in templatedata
	* "empty-undeclared": parameters with empty value, which do not exist in templatedata
	* "deprecated":  parameters with non-empty value, marked as "deprecated" in tempaltedata
	* "empty-deprecated":  parameters with empty value, marked as "deprecated" in tempaltedata
	* "empty-required": parameters marked as "required" in tempaltedata have no value
	* "any": at least one of the above properies has non-empty value, and the corresponding error actually exists.

if any of these error-conditions exists, the value associated with the corresponding key, if not empty, will be appended to the output,
after possibly replacing either one of two tokens: 
-- "templatename" is replaced with the actual template name, 
-- "paramname" is replaced by a comma-separated list of parameters offending the rule.
if the value of some key is null, it means this error condition will be ignored.

in addition, there are several other optional keys of the "options" structure:
	* "doc-subpage": if supplied, optional subpage to look for tempaltedata definition. typically it's "Documentation", or a translation
	* "ignore": list of parameter names which will be ignored, both in tempaltedata (for "required" and "deprecated" calculation), 
			or the template, for "undeclared" calculation

typically, this JSON structure will be placed in a special template, and retrieved for the module-use like so:
		<includeonly>{{#invoke:ParamValidatoe | validateParams | options = {{PV Default Values}} }}</includeonly>
this code is to be placed at the very beginning of the page of the template whose uses are to be validated.
	
several such options pages may exist, so the user can decide which validation regime to use with each template, by invoking it and passing
the appropriate one for the "options" parameter.

]]

function extract_options( frame )
	local options
	local args = frame.args

	local options = not empty( args.options ) and mw.text.jsonDecode( args.options ) or {}
 
	local n = 1
	while not empty( args['options' .. n] ) do
		local more = mw.text.jsonDecode( args['options' .. n] )
		for k, v in pairs(more) do options[k] = v end
		n = n + 1
	end
	
	return options
end

function build_namelist( options, template_name )
	if options and options['doc-subpage'] then
		return { template_name, template_name .. '/' .. options['doc-subpage'] }
	end
	return template_name
end

function empty( s )
	return not s or type( s ) == 'string' and mw.text.trim( s ) == ''
end

function validateParams( frame )
	local options = extract_options( frame )

	local t_frame = frame:getParent()
	local t_args, template_name = t_frame.args, t_frame:getTitle()
	local td_source = build_namelist( options, template_name )
	local templatedata = require( 'Module:ReadTd' ).ReadTemplateData( td_source )
	local td_p = templatedata.params	-- now we have options, template args, and td params metadata. we can work now.
	local report = ''

	local wrapreport = function()
		if empty( report ) then return '' end
		return ( options['report-prefix'] or "<div class = 'paramvalidator-wrapper'>" )
				.. report 
				.. ( options['report-suffix'] or "</div>" )
	end


	local ignore = function( p_name )
		for _, p in ipairs( options.ignore or {} ) do
			if p == p_name then return true end
		end
		return false
	end
	
	local replace_macros = function( s, param_names )
		s = mw.ustring.gsub( s, 'templatename', template_name )
		if type( param_names ) == 'table' then 
			param_names = table.concat( param_names, ', ' ) 
		end
		if param_names then
			s = mw.ustring.gsub( s, 'paramname', param_names )
		end
		return s
	end
	
	local report_params = function( key, param_names )
		if options[key] then 
			report = report .. replace_macros( options[key], param_names )
		end
	end

	local report_table = function( name, tbl )
		if #tbl ~= 0 then report_params( name, tbl ) end
	end
	
	if not templatedata then 
		report_params( { 'no-templatedata', 'any' } )
		return wrapreport() -- from this point on, we know templatedata is valid.
	end
	
	-- undeclared and deprecated contains only non-empty parameters.
	-- empty_undeclared contains undeclared parameters with no value 
	local undeclared, empty_undeclared, empty_required, deprecated, empty_deprecated = {}, {}, {}, {}, {}
	local undec = { [true] = empty_undeclared, [false] = undeclared }
	local dep = { [true] = empty_deprecated, [false] = deprecated }


	-- DO THE WORK: if paramete does not appear in TD, add it to undeclared or empty-undeclared. 
	-- if it does appear, check if it's deprecated, and if so, add it to deprecated or empty-deprecated  
	for p_name, value in pairs( t_args ) do 
		if not ignore( p_name ) then
			local noval = empty( value )
			if not td_p[p_name] then -- fill undeclared or undeclared_empty, depends on noval
				table.insert( undec[noval], p_name ) 
			elseif td_p[p_name].deprecated then
				table.insert( dep[noval], p_name )
			end
		end		
	end

	-- DO MORE WORK: collect "required" parameters that do not exist, or have empty value. 
	for p_name, param in pairs( td_p ) do
		if not ignore( p_name ) and param.required and empty( t_args[p_name] ) then
			table.insert( empty_required, p_name )
		end
	end
	
	-- WORK IS DONE. report the errors.
	report_table( 'empty-required', empty_required )
	report_table( 'undeclared', undeclared )
	report_table( 'empty-undeclared', empty_undeclared )
	report_table( 'deprecated', deprecated )
	report_table( 'empty-deprecated', empty_deprecated )
	if not empty( report ) then report_params( 'any' ) end
	
	return wrapreport()
end

return { 
	['validateparams'] = validateParams 
}