Module:TrainingPages

This module is intended to accept the name of a page (defaulting to the page currently being displayed), look it up in an index of pages, step forward or backward by some number of pages (usually 1), and give back the name of the page at that position.

Use {{#invoke:TrainingPages|function|parameters}} to invoke. For example:

{{#invoke:TrainingPages|last_page|index=Wikipedia:Training/For students/Editing module index|page=Wikipedia:Training/For students/Where to get help|defaultpage=Wikipedia:Training/header}} yields:

Module:TrainingPages error (index parameter):failed to access mw.title.new(Wikipedia:Training/For students/Editing module index):getContent() to load the index data

Functions

The available functions are:

• next_page: the next page on the index list

• last_page: the preceding page on the index list

• page_number: the number the page indicated is in the list

• total_pages: the total number of pages in the index

• main: allows you to flip forward or backward an arbitrary number of pages

Parameters

(All parameters are available to every function, except displacement which only matters for main)

• page is the page you are starting from (the one you're looking up in the index)

• if page is blank or omitted, the mw.title.getCurrentTitle() function is used to locate the current page. (So far as I know, this is always the page that matters, the one everything ultimately gets transcluded to, not the template or module)
• if page is a number and doesn't contain any text, the page that number of positions down in the index will be the base page used. With "main" and no displacement set, this returns the name of page#N. Otherwise you can have it return some number of pages off from that number, or the default page, as it would if the name of the page in that position had been entered as text.

• defaultpage is the page to be returned if there is no next page, previous page, or page displaced by n in the index. Can be blank, in which case the module output will be blank if this happens.

• index is the name of the index module with the list of all the pages. The pages should be in a list from beginning to end. There are three ways to format this:

• Index can be in module space (e.g. Module:TrainingPages/default index) in which case they must consist of return {'Name of first page','Name of second page','Name of third page' ... etc.}.
• Index can be in some other space, not in module format, in which case it need merely contain a list of Wikilinks in double square brackets. Everything outside the brackets is ignored, and every link in double square brackets is counted. The only limitation is that in this version anything in double square brackets is taken as a link, even if nowiki applies or it is in other brackets or has a newline in it or something that prevents it from appearing as a proper link. You can put a pair of nowiki or noninclude tags between the two opening square brackets as a kludge to avoid having this happen, if need be.
• (If omitted, the index still defaults to Module:TrainingPages/default index, so common tasks might be added to it. However, no provision has been made to prevent from paging from one set into another, so unless this only sees use in one consistent overall set of trainingpages that is a bad idea unless upgraded.)

• displacement specifies how many pages to go forward or back in the main module.

• noerr suppresses error messages if the index file can't be found; an empty string is returned.

• anonymize - any nonblank value causes project specific pages (Wikipedia:) to be returned as Project:

---

--The purpose of this module is to take a list of linked page, and use it to determine the next and previous page in the list as well as the total number of pages.
 
local p = {}
 
function anonymize(name)
    return mw.ustring.gsub(name,"^"..mw.site.siteName,"Project") or name
end
function out(name)
    return mw.ustring.gsub(name,"^Project",mw.site.siteName) or name
end
 
function p.main(frame,displacement,varstoreturn)
    local parent=frame.getParent(frame)
    local currentpage,indexmodule,defaultpage,noerr
    ---- args in the #invoke itself trump args in the parent frame
    currentpage = frame.args.page
    defaultpage = frame.args.defaultpage
    indexmodule = frame.args.index
    displacement = displacement or frame.args.displacement -- can get from function name
    noerr=frame.args.noerr
    anonymizereturn = frame.args.anonymize
    ---- args in the parent frame come next
    if parent then
        currentpage=currentpage or parent.args.page
        indexmodule=indexmodule or parent.args.index -- index is a module return{'page1','page2', ...}
        defaultpage=defaultpage or parent.args.defaultpage
        noerr=noerr or parent.args.noerr
        anonymizereturn = anonymizereturn or parent.args.anonymize
        end
    ---- default values if parameters aren't provided
    defaultpage=defaultpage or "" -- don't know where to send people by default
    if not(indexmodule) then
        return "[[Module:TrainingPages]] error:no index parameter specified"
    end
    if not(currentpage) then
        local pp=mw.title.getCurrentTitle()
        if not pp then
            if noerr then
                return "","",""
            else return "[[Module:TrainingPages]] error:failed to access getCurrentTitle" -- this shouldn't happen anyway, I don't think....
            end
        end
        currentpage=pp.fullText
    end
    currentpage=anonymize(currentpage) --- convert "Wikipedia:, "Meta:" etc. into "Project:
    local index={}
    if mw.ustring.sub(indexmodule,1,6)=="Module" then
        ---- get a table of the pages in order from indexmodule
        index=mw.loadData(indexmodule)
    else pp=mw.title.new(indexmodule)
        if not pp then
            if noerr then
                return "","",""
            else return "[[Module:TrainingPages]] error (''index'' parameter): failed to access mw.title.new("..tostring(indexmodule)..") to load the index file",false,false,true
            end
        end
        local textindex=pp.getContent(pp)
        if not textindex then
            if noerr then
                return "","",""
            else return "[[Module:TrainingPages]] error (''index'' parameter):failed to access mw.title.new("..indexmodule.."):getContent() to load the index data",false,false,true
            end
        end
        prowl=mw.ustring.gmatch(textindex,"%[%[(.-)[%]|]") -- first half of any wikilink
        index={}
        repeat
            link=prowl()
            if not(link) then break end
            if link~="" then table.insert(index,link) end
        until false
    end
    displacement=displacement or 0 -- assume a null parameter is just display the same
    ---- set up the reverse lookup in lookup.
    ---- it would be faster to set this up in the indexmodule
    ---- but we don't want inconsistencies from user input!
    local lookup={}
    local i=0
    repeat
        i=i+1
        local j=index[i]
        if j then lookup[anonymize(mw.uri.decode(j))]=i else break end -- lookup["page name"] => page number
    until false
    --- get the page to return
    local returnpage,currentpagenumber
    if tonumber(currentpage) then
        currentpagenumber=tonumber(currentpage)
        returnpage=index[currentpagenumber+displacement] or defaultpage
    else if (lookup[mw.uri.decode(currentpage)]) then
            currentpagenumber=lookup[currentpage]
            returnpage=index[currentpagenumber+displacement] or defaultpage
        else returnpage=defaultpage
        end
    end
    if anonymizereturn then
        returnpage=anonymize(returnpage)
    else
        returnpage=out(returnpage)
    end
    if not(varstoreturn) then return tostring(returnpage) else return tostring(returnpage),currentpagenumber,#index end
end
 
-- Return the next page in the index
-- Used like if on a page that is part of the index:
--{{#invoke:TrainingPages| next_page | index=Project:Training/For students/Editing module index }}
-- Used like this to find the next page after a specified page:
--{{#invoke:TrainingPages| next_page | index=Project:Training/For students/Editing module index | currentpage=Project:Training/For students/My sandbox }}
function p.next_page(frame)
    local returnpage,pagenumber,totalpages,errcode=p.main(frame,1,true)
    return returnpage
end
 
-- Same as above, but returns the previous page
function p.last_page(frame)
    local returnpage,pagenumber,totalpages,errcode=p.main(frame,-1,true)
    return returnpage
end
 
function p.page_number(frame)
    local returnpage,pagenumber,totalpages,errcode=p.main(frame,0,true)
    if errcode then return returnpage else return pagenumber end
end
 
function p.total_pages(frame)
    local returnpage,pagenumber,totalpages,errcode=p.main(frame,0,true)
    if errcode then return returnpage else return totalpages end
end
 
return p