Modul:PageTitleSimilar

 local PageTitleSimilar = { suite = "PageTitleSimilar",
 serial = "2025年02月11日",
 item = 0 }
 --[==[
 Check whether similar page name is existing
 ]==]
 local Failsafe = PageTitleSimilar
 local THIS = { }



 local fault = function ( alert )
 -- Format error message
 -- Precondition:
 -- alert -- string, with message
 -- Postcondition:
 -- Returns string
 local e = mw.html.create( "span" )
 :addClass( "error" )
 :wikitext( string.format( "%s * %s",
 PageTitleSimilar.suite,
 alert ) )
 return tostring( e )
 end -- fault()



 local find = function ( ask )
 -- Check whether page title exists in this namespace
 -- Precondition:
 -- ask -- string, with page title
 -- Postcondition:
 -- Returns true, if existing
 -- THIS.title is the title of an existing page
 local t = mw.title.new( ask, THIS.ns )
 local r
 if t then
 r = t.exists
 if r then
 THIS.title = t
 end
 end
 return r
 end -- find()



 local found = function ( apply )
 -- Communicate match by transclusion
 -- Precondition:
 -- apply -- string, with message type
 -- -- Typogr
 -- -- URL
 -- THIS.title has been defined
 -- Postcondition:
 -- Returns string
 local source = "source" .. apply
 local shift = THIS.JSON[ source ]
 local r
 if type( shift ) == "string" then
 local t = mw.title.new( shift )
 if t and t.exists then
 local params = { ["1"] = THIS.title.prefixedText }
 r = THIS.frame:expandTemplate{ title = t,
 args = params }
 end
 end
 if not r then
 r = fault( "missing transclusion for " .. source )
 end
 return r
 end -- found()



 local fraction = function ()
 -- Try URL completion when common special chars were truncated
 -- Postcondition:
 -- Returns string, or not
 local s = THIS.self
 local r
 if s:find( "(", 1, true ) then
 find( s .. ")" )
 end
 if not THIS.title then
 local shift = s .. "."
 if not find( shift ) then
 shift = s .. "?"
 find( shift )
 end
 end
 if THIS.title then
 r = found( "URL" )
 end
 return r
 end -- fraction()



 local further = function ()
 -- Try improvements by typographical chars
 -- Postcondition:
 -- Returns string, or not
 local rep = THIS.JSON.replace
 local r
 if type( rep ) == "table" then
 local s = THIS.self
 local shift
 for k, v in pairs( rep ) do
 if type( v[ 1 ] ) == "string" and
 type( v[ 2 ] ) == "string" then
 shift = mw.ustring.gsub( s, v[ 1 ], v[ 2 ] )
 if shift ~= s then
 if find( shift ) then
 r = found( "Typogr" )
 break -- for k, v
 else
 s = shift
 end
 end
 else
 r = fault( string.format( "replace[%s]", k ) )
 break -- for k, v
 end
 end -- for k, v
 end
 return r
 end -- further()



 Failsafe.failsafe = function ( atleast )
 -- Retrieve versioning and check for compliance
 -- Precondition:
 -- atleast -- string, with required version
 -- or wikidata|item|~|@ or false
 -- Postcondition:
 -- Returns string -- with queried version/item, also if problem
 -- false -- if appropriate
 -- 2024年03月01日
 local since = atleast
 local last = ( since == "~" )
 local linked = ( since == "@" )
 local link = ( since == "item" )
 local r
 if last or link or linked or since == "wikidata" then
 local item = Failsafe.item
 since = false
 if type( item ) == "number" and item > 0 then
 local suited = string.format( "Q%d", item )
 if link then
 r = suited
 else
 local entity = mw.wikibase.getEntity( suited )
 if type( entity ) == "table" then
 local seek = Failsafe.serialProperty or "P348"
 local vsn = entity:formatPropertyValues( seek )
 if type( vsn ) == "table" and
 type( vsn.value ) == "string" and
 vsn.value ~= "" then
 if last and vsn.value == Failsafe.serial then
 r = false
 elseif linked then
 if mw.title.getCurrentTitle().prefixedText
 == mw.wikibase.getSitelink( suited ) then
 r = false
 else
 r = suited
 end
 else
 r = vsn.value
 end
 end
 end
 end
 elseif link then
 r = false
 end
 end
 if type( r ) == "nil" then
 if not since or since <= Failsafe.serial then
 r = Failsafe.serial
 else
 r = false
 end
 end
 return r
 end -- Failsafe.failsafe()



 -- Export
 local p = { }

 p.f = function ( frame )
 local source = frame.args[ 1 ]
 local r, scream
 if source then
 local lucky
 lucky, THIS.JSON = pcall( mw.loadJsonData, source )
 if lucky then
 local t = mw.title.getCurrentTitle()
 THIS.frame = frame
 THIS.ns = t.ns
 THIS.self = t.prefixedText
 if frame.args.URL == "1" then
 r = fraction()
 end
 if not r then
 r = further()
 end
 else
 scream = "no valid JSON found: " .. mw.text.nowiki( source )
 end
 else
 scream = "invoked without JSON"
 end
 if scream then
 r = fault( scream )
 end
 return r or ""
 end -- p.f



 p.failsafe = function ( frame )
 -- Versioning interface
 local s = type( frame )
 local since
 if s == "table" then
 since = frame.args[ 1 ]
 elseif s == "string" then
 since = frame
 end
 if since then
 since = mw.text.trim( since )
 if since == "" then
 since = false
 end
 end
 return Failsafe.failsafe( since ) or ""
 end -- p.failsafe

 return p