Module:Extract short description
require('strict');
--[[--------------------------< E X T R A C T _ F R O M _ T E M P L A T E >------------------------------------
no direct template access
extracts short description text from a named template in the named article when that template is found in article
wiki source
requires three arguments:
frame: frame object required to preprocess template_name
article_title: the name of the article to inspect - correct spelling and captialization is required
template_names_tbl: a single template name (a string) or a table of one or more template names all without
namespace to be inspected - correct spelling and captialization is required
returns two values:
on success, returns the short description text and true
on failure, returns error message and nil
]]
local function extract_from_template (frame, article_title, template_names_tbl)
local content = mw.title.new (article_title):getContent(); -- read the unparsed article source
if not content then
return 'error: no article: ' .. article_title .. '';
end
local template_name_pattern;
local start;
if 'string' == type (template_names_tbl) then -- when single template name passed in as a string
template_names_tbl = {template_names_tbl}; -- convert to a table
end
local templateName
for _, template_name in ipairs (template_names_tbl) do -- loop through the name in the table
template_name_pattern = template_name:gsub ('^%a', string.lower):gsub ('^%a', '%[%1%1%]'):gsub ('%[%a', string.upper); -- make lua pattern for initial letter upper or lower case: A -> [Aa]
start = content:find ('{{%s*' .. template_name_pattern); -- find the start of {{template name ...;
if start then
templateName = template_name
break; -- found a matching template
end
end
if not start then -- no templates found: return name of first template in template_names_tbl in error message
return 'error: no template: ' .. template_names_tbl[1] .. ' in: ' .. article_title .. '';
end
local text = string.match (content, '%b{}', start); -- start points to first { of the templateName
if not text then
return 'error: failed to extract template: ' .. templateName .. '';
end
text = text:gsub ('
text = text:gsub ('
text = text:gsub ('{{%s*sfn[^}]-}}', ''); -- delete sfn template which make references using {{#tag:}} parser functions
text = text:gsub ('{{#tag:ref[^}]-}}', ''); -- and delete these too
text = frame:preprocess (text):match ('
if not text then
return 'error: no short description text in: ' .. templateName .. ' in '.. article_title .. '';
end
return mw.text.trim (text), true; -- trim whitespace and done
-- preprocess the template then apply syntax highlighting
-- this will display the preprocessed template; not usable here
-- for much other than debugging because syntaxhighlight returns a stripmarker
-- return template_name .. frame:callParserFunction ('#tag:syntaxhighlight', frame:preprocess (text));
end
--[[--------------------------< E X T R A C T _ F R O M _ A R T I C L E >--------------------------------------
no direct template access
extracts short description text from {{short description}} template when that template is found in article wiki
source; searches for both the long name (short description) and the short-name redirect (SHD); if both are present
long name controls; if multiples of the same name are present, the first-found controls.
requires one argument: article_title is the name of the article to be inspected
on success, returns the short description text; error message else
]]
local function extract_from_article (article_title)
local content = mw.title.new (article_title):getContent(); -- read the unparsed article source
if not content then
return 'error: no article: ' .. article_title .. '';
end
local text, start;
start = string.find (content, '{{%s*[Ss]hort description') or -- find the start of {{Short description}} template
string.find (content, '{{%s*SHD'); -- not full name, try the {{SHD}} redirect
if not start then
return 'error: no short description in: ' .. article_title .. '';
end
text = content:match ('%b{}', start); -- get the short description template; start points to first { of the template
if not text then
return 'error: failed to extract short description template from ' .. article_title .. '';
end
text = text:match ('^[^|}]+|%s*(.+)%s*}}$'); -- strip '{{template name|' and '}}'; trim leading and trailing whitespace
return text and text or 'error: no short description text in: ' .. article_title .. '';
end
--[[--------------------------< E X T R A C T _ S H O R T _ D E S C R I P T I O N >----------------------------
template entry point:
{{#invoke:extract short description|extract_short_description}}
search for and return text that is used by the {{short description}} template. {{Short description}}, also {{SHD}}
may be located in article wikisource or embedded in a template (commonly an infobox template). When neither of
|template= and {{{2|}}} are set, this code will look in the article wiki source; when set, this code look inside the
named template.
This template entry takes two parameters:
{{{1}}} or |article=: required; name of wiki article from which to extract the short description
{{{2}}} or |template=; optional; name of template that holds the {{short description}} template
on success, returns the short description text; error message else
]]
local function extract_short_description (frame)
local getArgs = require('Module:Arguments').getArgs;
local args = getArgs(frame);
if args[1] and args.article then -- both assigned, fail with an error message
return 'error: conflicting |{{{1}}} and |article= parameters';
end
local article_title = args[1] or args.article; -- the required parameter
if not article_title then -- not supplied, fail with an error message
return 'error: article title required';
end
local template_name = args[2] or args.template; -- optional
if template_name then
local text, _ = extract_from_template (frame, article_title, template_name); -- ignore second return value
return text;
else
return extract_from_article (article_title);
end
end
--[[--------------------------< E X P O R T E D F U N C T I O N S >------------------------------------------
]]
return {
extract_short_description = extract_short_description,
extract_from_template = extract_from_template,
extract_from_article = extract_from_article,
}