Module:Parameter validation/doc

Usage
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 templatedata was found in template 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 templatedata
 * empty-deprecated parameters with empty value, marked as "deprecated" in templatedata
 * empty-required missing or empty parameter marked as "required" in templatedata
 * 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 template' using #invoke. it expects a parameter named "options", which contains the definition of the output. typically, it's used by placing something like so: 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   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: if the returned table is empty, no violation were found, and an empty string is returned and nothing else happens.
 * calculateViolations( frame, subpages )

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. 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.
 * 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 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 )
 * wrapper-suffix closing wrapper element of output (defaults to "  ")

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

Attribution
This module is based on idea and original code of User:IKhitron.

the source of this module is in he:Module:ParamValidator.