@@ Line 1: / Line 1: @@
 -- This module follows [[User:Ganaram inukshuk/Provisional style guide for Lua]]
 local getArgs = require("Module:Arguments").getArgs
+local iutils  = require("Module:Introspection utils")
+local yesno   = require("Module:Yesno")
 local p = {}
+-- TODO: (Low-ish priority): rewrite to eliminate redundant code
 -- Produces a hatnote that is placed on the top of a documentation page (either
 -- template or module documentation) and can autodetect and categorize:
 -- - FOR MODULES:
---   - whether a module has an accompanying template (overridable)
+--   - whether a module has an accompanying template (overridable/toggleable)
 --   - whether a module is meant as a library for other modules
 -- - FOR TEMPLATES:
---   - whether a template has an accompanying module (overridable)
+--   - whether a template has an accompanying module (overridable/toggleable)
 --   - what functions from which modules are invoked
--- Options for specific types of templates and modules include:
+-- Helper function: categorize modules
--- - (TEMPLATES) whether it's a metatemplate
+local function categorize_module(pagename)
--- - (MODULES) whether it's a metamodule (used the same way as a metatemplate,
+	local cats = ""
---   but direct use of module code is allowed)
+	if pagename:match("/doc$") then
+		cats = "[[Category:Module documentation]]"
+	else
+		cats = "[[Category:Lua modules]]"
+	end
+	return cats
+end
--- Detect whether a page exists, where pagename is "Namespace:Title"
+-- Helper function to handle modules
-function p.page_exists(fullpagename)
+function p.make_module_hatnote(header, pagename, corr_template, detect_corr_page)
-	local title = mw.title.new(fullpagename)
+	-- Check whether corresponding template exists
+	-- Then check whether that template invokes the module
+	local has_template = iutils.page_exists("Template:" .. corr_template:gsub("/doc$", ""))
-	if title and title.exists then
+	-- Check whether to use detect_corr_page option
-		return true
+	-- If the header option is dualuse, metatemplate, or noinvoke, this option
+	-- is ignored. For any other option, it's not.
+	if header ~= "dualuse" and header ~= "metatemplate" and header ~= "noinvoke" then
+		has_template = has_template and detect_corr_page
+	end
+	-- If the module has a template, check for whether it invokes it.
+	if has_template then
+		local wikitext = iutils.get_and_preprocess_content("Template", corr_template:gsub("/doc$", ""))
+		local invokes = iutils.find_invokes(wikitext)
+		has_template = has_template and iutils.invocation_exists(invokes, pagename:gsub("/doc$", ""))
+	end
+	-- Heading meanings and usage on module
+	-- - dualuse means a template is implement by a module, but its template may
+	--   be bypassed by using its module directly from other modules.
+	-- - metatemplate is a special case of dualuse; the template-module pair is
+	--   for a metatemplate, a template used to build other templates.
+	-- - noinvoke indicates a lua-based template, but the module's code is so
+	--   specialized that its code should not be used by other modules or
+	--   invoked by other templates.
+	-- - metamodule and library indicate a module whose code is used mainly for
+	--   other modules. Such modules generally don't have a corresponding
+	--   template.
+	-- - data/datamodule indicates a module whose purpose is to provide data
+	--   values to other modules. Like library modules, these don't have a
+	--   corresponding template.
+	-- Does the module have a template?
+	-- - dualuse, metatemplate, and noinvoke: YES (REQUIRED!!)
+	-- - metamodule/library and data: GENERALLY NO
+	local result = ""
+	if header == "dualuse" then
+		if has_template then
+			result = string.format(
+				"This module may be invoked by templates using its corresponding template [[Template:%s]], or used directly from other modules.",
+				corr_template:gsub("/doc$", "")
+			)
+		else
+			result = string.format(
+				"This module has a corresponding template that is currently missing or does not use this module. ([[Special:EditPage/Template:%s|edit template]])",
+				corr_template:gsub("/doc$", "")
+			)
+		end
+	elseif header == "metatemplate" then
+		if has_template then
+			result = string.format(
+				"This module implements a metatemplate, and may be invoked by templates using its corresponding template [[Template:%s]], or used directly from other modules.",
+				corr_template:gsub("/doc$", "")
+			)
+		else
+			result = "This module is used to create other Lua-based templates and has no corresponding template."
+		end
+	elseif header == "noinvoke" then
+		if has_template then
+			result = string.format(
+				"This module should not be invoked directly; use its corresponding template instead: [[Template:%s]].",
+				corr_template:gsub("/doc$", "")
+			)
+		else
+			result = string.format(
+				"This module implements a template that is currently missing or does not use this module. ([[Special:EditPage/Template:%s|edit template]])",
+				corr_template:gsub("/doc$", "")
+			)
+		end
+	elseif header == "library" or header == "metamodule" then
+		result = "This module primarily serves as a library for other modules and has no corresponding template."
+	elseif header == "data" or pagename:gsub("/doc$", ""):match("/data$") then
+		result = "This module primarily serves to provide data values for other modules and has no corresponding template."
+	elseif header == "none" then
+		result = ""
 	else
-		return false
+		if has_template and header ~= "" then
+			result = string.format("%s This module implements [[Template:%s]].", header, corr_template:gsub("/doc$", ""))
+		elseif has_template and header == "" then
+			result = string.format("This module implements [[Template:%s]].", corr_template:gsub("/doc$", ""))
+		else
+			result = header
+		end
+	end
+	-- Produce categories
+	local cats = categorize_module(pagename)
+	-- Return
+	if result == "" then
+		return "" .. cats
+	else
+		return string.format(": ''%s''%s\n", result, cats)
 	end
 end
-function p.categorize(namespace, pagename, is_lua_based_template)
+-- Helper function: categorize template
-	local is_lua_based_template = is_lua_based_template or false
+local function categorize_template(pagename, has_invoke, is_metatemplate)
 	local cats = ""
+	if pagename:match("/doc$") then
-	if pagename:sub(-4) == "/doc" then
+		cats = "[[Category:Template documentation]]"
-		-- Documentation subpages
+	else
-		if namespace == "Template" then
+		cats = "[[Category:Templates]]"
-			cats = "[[Category:Template documentation]]"
+		if has_invoke then
-		elseif namespace == "Module" then
+			cats = cats .. " [[Category:Lua-based templates]]"
-			cats = "[[Category:Module documentation]]"
 		end
-	else
+		if is_metatemplate then
-		-- Main pages
+			cats = cats .. " [[Category:Metatemplates]]"
-		if namespace == "Template" then
-			cats = "[[Category:Templates]]"
-			if is_lua_based_template then
-				cats = cats .. " [[Category:Lua-based templates]]"
-			end
-		elseif namespace == "Module" then
-			cats = "[[Category:Lua modules]]"
 		end
 	end
 	return cats
 end
-function p._dochead(args)
+-- Helper function
-	local namespace = args["namespace"]
+-- Creates an additional hatnote denoting which functions are invoked from which
-	local pagename  = args["pagename"]
+-- modules, if a has more than one invoke.
-	local header    = args["header"] or "none"
+local function make_invocation_hatnote(invokes)
-	local corr_template = args["temp"] or ("Template:" .. pagename)
+	local hatnote = ""
-	local corr_module   = args["mod"]  or ("Module:"   .. pagename)
+	if #invokes == 0 then
+		return ""
+	else
+		hatnote = "This template invokes the following functions:"
+		local calls = {}
+		for _, call in ipairs(invokes) do
+			local module_link = iutils.make_module_link(call.module)
+			table.insert(calls, string.format("'''%s''' from %s", call.func, module_link))
+		end
+		return string.format("%s %s.", hatnote, table.concat(calls, ", "))
+	end
+end
-	-- If header is none, don't bother
+-- Helper function to handle templates
-	if header == "none" then
+function p.make_template_hatnote(header, pagename, corr_module, detect_corr_page)
-		return p.categorize(namespace, pagename)
+	-- Check whether corresponding module exists
+	-- Then check whether this template invokes the module
+	local has_module = iutils.page_exists("Module:" .. corr_module:gsub("/doc$", ""))
+	-- Check whether to use detect_corr_page option
+	-- If the header option is dualuse or metatemplate, this option is ignored.
+	-- For any other option, it's not (although it also has no effect on
+	-- noinvoke or library/metamodule).
+	if header ~= "dualuse" and header ~= "metatemplate" then
+		has_module = has_module and detect_corr_page
 	end
-	-- Remove doc subpage if present
+	-- Check for whether the template invokes that module, regardless of whether
-	corr_template = corr_template:gsub("/doc$", "")
+	-- it uses the corresponding module.
-	corr_module   = corr_module  :gsub("/doc$", "")
+	local wikitext = iutils.get_and_preprocess_content("Template", pagename:gsub("/doc$", ""))
+	local invokes = iutils.find_invokes(wikitext)
+	local is_module_invoked = iutils.invocation_exists(invokes, corr_module:gsub("/doc$", ""))
+	-- Heading meanings and usage on templates
+	-- - dualuse means a template is implement by a module, but its template may
+	--   be bypassed by using its module directly from other modules.
+	-- - metatemplate is a special case of dualuse; the template-module pair is
+	--   for a metatemplate, a template used to build other templates.
+	-- - noinvoke and metamodule/library don't have use for templates.
+	-- Does the template have a module?
+	-- - dualuse and metatemplate: YES (REQUIRED!!)
+	-- - noinvoke, metamodule/library, and data/datamodule: option's don't apply
+	--   to templates.
+	-- RATIONALE FOR NOINVOKE NOT APPLYING: a template may invoke functions from
+	-- more than one module, but one of them must be the "main" module. Since
+	-- there's no way to autodetect that, that info must be manually entered.
+	-- If that doesn't happen
 	local result = ""
-	local has_template = p.page_exists(corr_template)
-	local has_module   = p.page_exists(corr_module)
-	-- Handle each header type first
 	if header == "dualuse" then
-		if namespace == "Module" then
+		if has_module and is_module_invoked then
-			if has_template then
+			result = string.format(
-				result = string.format("This module may be invoked by templates using its corresponding [[%s|template]], or used directly from other modules.", corr_template)
+				"This template is implemented by the Lua module [[Module:%s]]. See its module page for Lua-based template implementation.",
-			else
+				corr_module:gsub("/doc$", "")
-				result = header
+			)
-			end
+		elseif has_module and not is_module_invoked then
+			result = string.format(
+				"This template has a corresponding Lua module [[Module:%s]], but does not invoke its functions.",
+				corr_module:gsub("/doc$", "")
+			)
 		else
-			result = "This template or its options is in the wrong namespace. It should be used within the Module namespace."
+			result = string.format(
+				"This template is implemented by a module that is currently missing. [[Special:EditPage/Module:%s]]",
+				corr_module:gsub("/doc$", "")
+			)
 		end
 	elseif header == "metatemplate" then
-		if namespace == "Module" then
+		if has_module and is_module_invoked then
-			if has_template then
+			result = string.format(
-				result = string.format("This module implements a metatemplate, and may be invoked by templates using its corresponding [[%s|template]], or used directly from other modules.", corr_template)
+				"This template is a metatemplate. It is used to build other templates and should not be used standalone, except for testing or simple usage. This template is implemented by the Lua module [[Module:%s]].",
-			else
+				corr_module:gsub("/doc$", "")
-				result = "This module implements a metatemplate."
+			)
-			end
+		elseif has_module and not is_module_invoked then
-		elseif namespace == "Template" then
+			result = string.format(
-			if has_module then
+				"This metatemplate has a corresponding Lua module [[Module:%s]], but does not invoke its functions.",
-				result = string.format("This template is a metatemplate. It is used to build other templates and should not be used standalone, except for testing or simple usage. This template is implemented by the Lua module [[%s]].", corr_module)
+				corr_module:gsub("/doc$", "")
-			else
+			)
-				result = "This template is a metatemplate. It is used to build other templates and should not be used standalone, except for testing or simple usage."
-			end
 		else
-			result = "This template or its options is in the wrong namespace. It should be within the Template or Module namespaces."
+			result = "This template is a metatemplate. It is used to build other templates and should not be used standalone, except for testing or simple usage."
 		end
-	elseif header == "noinvoke" then
+	elseif header == "noinvoke" or header == "library" or header == "metamodule" or header == "data" or header == "datamodule" then
-		if namespace == "Module" then
+		result = "This template has a header option in the wrong namespace. It should be used within the Module namespace."
-			if has_template then
-				result = string.format("This module should not be invoked directly; use its corresponding [[%s|template]] instead.", corr_template)
+	else
-			else
+		if has_module and header ~= "" and is_module_invoked then
-				result = header
+			result = string.format(
-			end
+				"%s. This template is implemented by the Lua module [[Module:%s]].",
+				header,
+				corr_module:gsub("/doc$", "")
+			)
+		elseif has_module and header ~= "" and not is_module_invoked then
+			result = string.format(
+				"%s. This template has a corresponding Lua module [[Module:%s]], but does not invoke its functions.",
+				header,
+				corr_module:gsub("/doc$", "")
+			)
+		elseif has_module and header == "" and is_module_invoked then
+			result = string.format(
+				"This template is implemented by the Lua module [[Module:%s]].",
+				corr_module:gsub("/doc$", "")
+			)
+		elseif has_module and header == "" and not is_module_invoked then
+			result = string.format(
+				"This template has a corresponding Lua module [[Module:%s]], but does not invoke its functions.",
+				corr_module:gsub("/doc$", "")
+			)
 		else
-			result = "This template or its options is in the wrong namespace. It should be used within the Module namespace."
+			result = header
 		end
+	end
+	-- Find all invocations for the template and add it as an addl hatnote.
+	local invocation_hatnote = make_invocation_hatnote(invokes)
+	-- Categorize
+	local cats = categorize_template(pagename, #invokes > 0, header == "metatemplate")
+	if header == "none" then
+		return cats
+	elseif result == "" and invocation_hatnote == "" then
+		return ""
+	elseif result == "" and invocation_hatnote ~= "" then
+		return string.format(": ''%s''%s\n", invocation_hatnote, cats)
+	elseif result ~= "" and invocation_hatnote == "" then
+		return string.format(": ''%s''%s\n", result, cats)
+	else
+		return string.format(": ''%s''\n: ''%s'' %s\n", result, invocation_hatnote, cats)
+	end
+end
+-- Main function
+function p._dochead(args)
+	local namespace = args["namespace"]
+	local pagename  = args["pagename"]
+	local header    = args["header"] or "none"
+	local corr_template = args["temp"] or pagename
+	local corr_module   = args["mod"]  or pagename
+	local detect_corr_page = args["detect_corr_page"]
-	elseif header == "library" or header == "metamodule" then
+	-- If header is none, skip everything
-		if namespace == "Module" then
+	if header == "none" then
-			result = "This module primarily serves as a library for other modules."
+		--return categorize(namespace, pagename)
-		else
+	end
-			result = "This template or its options is in the wrong namespace. It should be used within the Module namespace."
-		end
+	-- Call appropriate hatnote-making function
+	-- Remove /doc suffix if this is on a /doc page to ensure links are made
+	-- properly. :gsub("/doc$", "")
+	local result = ""
+	if namespace == "Module" then
+		result = p.make_module_hatnote(header, pagename, corr_template, detect_corr_page)
+	elseif namespace == "Template" then
+		result = p.make_template_hatnote(header, pagename, corr_module, detect_corr_page)
 	else
-		if namespace == "Module" then
+		result = ": ''This documentation template is in the wrong namespace. It should be within the Template or Module namespaces.''\n"
-			if has_template then
-				result = string.format("%s This module implements [[%s]].", header, corr_template)
-			else
-				result = header
-			end
-		elseif namespace == "Template" then
-			if has_module then
-				result = string.format("%s This template is implemented by the Lua module [[%s]].", header, corr_module)
-			else
-				result = header
-			end
-		else
-			result = "This template or its options is in the wrong namespace. It should be used within the Template or Module namespaces."
-		end
 	end
-	-- Append categorization info
+	return result
-	local has_link = namespace == "Template" and has_module
-	return string.format(":''%s'' %s", result, p.categorize(namespace, pagename, has_link))
 end
+-- Wrapper to be invoked
 function p.dochead(frame)
 	local args = getArgs(frame, { removeBlanks = true }) or {}
@@ Line 152: / Line 323: @@
 	args["namespace"] = args["namespace"] or title.nsText
 	args["pagename" ] = args["pagename" ] or title.text
-	args["header"   ] = args["header"   ] or args["namespace"] == "Module" and "noinvoke" or ""
+	-- Extract header or set it to defaults
+	if args["header"] == nil or args["header"] == "" then
+		if args["namespace"] == "Module" then
+			args["header"] = "noinvoke"
+		else
+			args["header"] = ""
+		end
+	end
 	-- Extract template/module names, or autogenerate them
-	args["temp"] = args["temp"] or ("Template:" .. args["pagename"])
+	args["temp"] = args["temp"] or args["pagename"]
-	args["mod" ] = args["mod" ] or ("Module:"   .. args["pagename"])
+	args["mod" ] = args["mod" ] or args["pagename"]
+	-- Option to detect corresponding page (default true)
+	args["detect_corr_page"] = args["detect_corr_page"] == nil and true or yesno(args["detect_corr_page"])
+	local result = p._dochead(args)
+    -- Debugger option to show generated WikiText
+    local wtext = yesno(frame.args["wtext"] or args["wtext"])
+	if wtext == true then
+		result = "<syntaxhighlight lang=\"wikitext\">" .. result .. "</syntaxhighlight>"
+	end
+	return frame:preprocess(result)
+end
+function p.tester()
+	local args = {}
+	args["namespace"] = "Template"
+	args["pagename" ] = "Module introspection"
+	args["temp"] = args["pagename"]
+	args["mod" ] = args["pagename"]
+	args["header"] = ""
 	return p._dochead(args)
 end
 return p

Module:Dochead: Difference between revisions