Modul:JSONutil

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Die Dokumentation für dieses Modul kann unter Modul:JSONutil/Doku erstellt werden

local JSONutil = { suite  = "JSONutil",
                   serial = "2019-05-29",
                   item   = 63869449 }
--[=[
preprocess JSON data
]=]



JSONutil.more = 50    -- length of trailing context



local Fallback = function ()
    -- Retrieve current default language code
    --     Returns  string
    return mw.language.getContentLanguage():getCode()
                                           :lower()
end -- Fallback()



JSONutil.failsafe = function ( atleast )
    -- Retrieve versioning and check for compliance
    -- Precondition:
    --     atleast  -- string, with required version or "wikidata"
    --                 or false
    -- Postcondition:
    --     Returns  string with appropriate version, or false
    local since = atleast
    local r
    if since == "wikidata" then
        local item = JSONutil.item
        since = false
        if type( item ) == "number"  and  item > 0 then
            local entity = mw.wikibase.getEntity( string.format( "Q%d",
                                                                 item ) )
            if type( entity ) == "table" then
                local vsn = entity:formatPropertyValues( "P348" )
                if type( vsn ) == "table"  and
                   type( vsn.value ) == "string" and
                   vsn.value ~= "" then
                    r = vsn.value
                end
            end
        end
    end
    if not r then
        if not since  or  since <= JSONutil.serial then
            r = JSONutil.serial
        else
            r = false
        end
    end
    return r
end -- JSONutil.failsafe()



JSONutil.fair = function ( apply )
    -- Reduce enhanced JSON data to strict JSON
    -- Parameter:
    --     apply  -- string, with enhanced JSON
    -- Returns:
    --     1    -- string|nil|false, with error keyword
    --     2    -- string, with JSON or context
    local m   = 0
    local n   = 0
    local s   = mw.text.trim( apply )
    local sep = string.char( 10 )
    local i, j, r, scan, sep0, sep1, stab, start, stub, suffix
    local framework = function ( a )
                              -- syntax analysis outside strings
                              local k = 1
                              local c
                              while k do
                                  k = a:find( "[{%[%]}]", k )
                                  if k then
                                      c = a:byte( k, k )
                                      if c == 0x7B then    -- {
                                          m = m + 1
                                      elseif c == 0x7D then    -- }
                                          m = m - 1
                                      elseif c == 0x5B then    -- [
                                          n = n + 1
                                      else    -- ]
                                          n = n - 1
                                      end
                                      k = k + 1
                                  end
                              end   -- while k
                      end
    if s:sub( 1, 1 ) == '{' then
        stab = string.char( 9 )
        s    = s:gsub( string.char( 13, 10 ),  sep )
                :gsub( string.char( 13 ),  sep )
        stub = s:gsub( sep, "" ):gsub( stab, "" )
        scan = string.char( 0x5B, 0x01, 0x2D, 0x1F, 0x5D )
        j    = stub:find( scan )
        if j then
            r = "ControlChar"
            s = s:sub( j + 1,  j + JSONutil.more )
        else
            i    = true
            j    = 1
            sep0 = string.char( 0x5B, 0x22, 0x27, 0x5D )    -- [ " ' ]
            sep1 = string.char( 0x5B, 0x5C, 0x22, 0x5D )    -- [ \ " ]
        end
    else
        r = "Bracket0"
        s = s:sub( 1, JSONutil.more )
    end
    while i do
        i = s:find( sep0, j )
        if i then
            if j == 1 then
                framework( s:sub( 1, i - 1 ) )
            end
            if s:sub( i, i ) == '"' then
                stub = s:sub( j,  i - 1 )
                if stub:find( '[^"]*,%s*[%]}]' ) then
                    r = "CommaEnd"
                    s = stub:sub( 1, JSONutil.more )
                    i = false
                    j = false
                else
                    if j > 1 then
                        framework( stub )
                    end
                    i = i + 1
                    j = i
                end
                while j do
                    j = s:find( sep1, j )
                    if j then
                        if s:sub( j, j ) == '"' then
                            start  = s:sub( 1,  i - 1 )
                            suffix = s:sub( j )
                            if j > i then
                                stub = s:sub( i,  j - 1 )
                                        :gsub( sep,  "\\n" )
                                        :gsub( stab, "\\t" )
                                j = i + stub:len()
                                s = string.format( "%s%s%s",
                                                   start, stub, suffix )
                            else
                                s = start .. suffix
                            end
                            j = j + 1
                            break   -- while j
                        else
                            j = j + 2
                        end
                    else
                        r = "QouteEnd"
                        s = s:sub( i,  i + JSONutil.more )
                        i = false
                    end
                end   -- while j
            else
                r = "Qoute"
                s = s:sub( i,  i + JSONutil.more )
                i = false
            end
        else
            stub = s:sub( j )
            if stub:find( '[^"]*,%s*[%]}]' ) then
                r = "CommaEnd"
                s = stub:sub( 1, JSONutil.more )
            else
                framework( stub )
            end
        end
    end   -- while i
    if not r   and   ( m ~= 0  or  n ~= 0 ) then
        if m ~= 0 then
            s = "}"
            if m > 0 then
                r = "BracketCloseLack"
                j = m
            elseif m < 0 then
                r = "BracketClosePlus"
                j = -m
            end
        else
            s = "]"
            if n > 0 then
                r = "BracketCloseLack"
                j = n
            else
                r = "BracketClosePlus"
                j = -n
            end
        end
        if j > 1 then
            s =  string.format( "%d %s", j, s )
        end
    end
    if r and s then
        s = mw.text.encode( s:gsub( sep,  " " ) ):gsub( "|", "&#124;" )
    end
    return r, s
end -- JSONutil.fair()



JSONutil.fault = function ( alert, add, adapt )
    -- Retrieve formatted message
    -- Parameter:
    --     alert  -- string, with error keyword, or other text
    --     add    -- string|nil|false, with context
    --     adapt  -- function|string|table|nil|false, for I18N
    -- Returns string, with HTML span
    local e = mw.html.create( "span" )
                     :addClass( "error" )
    local s = alert
    if type( s ) == "string" then
        s = mw.text.trim( s )
        if s == "" then
            s = "EMPTY JSONutil.fault key"
        end
        if not s:find( " ", 1, true ) then
            local storage = string.format( "I18n/Module:%s.tab",
                                           JSONutil.suite )
            local lucky, t = pcall( mw.ext.data.get, storage, "_" )
            if type( t ) == "table" then
                t = t.data
                if type( t ) == "table" then
                    local e
                    s = "err_" .. s
                    for i = 1, #t do
                        e = t[ i ]
                        if type( e ) == "table" then
                            if e[ 1 ] == s then
                                e = e[ 2 ]
                                if type( e ) == "table" then
                                    local q = type( adapt )
                                    if q == "function" then
                                        s = adapt( e, s )
                                        t = false
                                    elseif q == "string" then
                                        t = mw.text.split( adapt, "%s+" )
                                    elseif q == "table" then
                                        t = adapt
                                    else
                                        t = { }
                                    end
                                    if t then
                                        table.insert( t, Fallback() )
                                        table.insert( t, "en" )
                                        for k = 1, #t do
                                            q = e[ t[ k ] ]
                                            if type( q ) == "string" then
                                                s = q
                                                break   -- for k
                                            end
                                        end   -- for k
                                    end
                                else
                                    s = "JSONutil.fault I18N bad #" ..
                                        tostring( i )
                                end
                                break   -- for i
                            end
                        else
                            break   -- for i
                        end
                    end   -- for i
                else
                    s = "INVALID JSONutil.fault I18N corrupted"
                end
            else
                s = "INVALID JSONutil.fault commons:Data: " .. type( t )
            end
        end
    else
        s = "INVALID JSONutil.fault key: " .. tostring( s )
    end
    if type( add ) == "string" then
        s = string.format( "%s &#8211; %s", s, add )
    end
    e:wikitext( s )
    return tostring( e )
end -- JSONutil.fault()



JSONutil.fetch = function ( apply, always, adapt )
    -- Retrieve JSON data, or error message
    -- Parameter:
    --     apply   -- string, with presumable JSON text
    --     always  -- true, if apply is expected to need preprocessing
    --     adapt   -- function|string|table|nil|false, for I18N
    -- Returns table, with data, or string, with error as HTML span
    local lucky, r
    if not always then
        lucky, r = pcall( mw.text.jsonDecode, apply )
    end
    if not lucky then
        lucky, r = JSONutil.fair( apply )
        if lucky then
            r = JSONutil.fault( lucky, r, adapt )
        else
            lucky, r = pcall( mw.text.jsonDecode, r )
            if not lucky then
                r = JSONutil.fault( r, false, adapt )
            end
        end
    end
    return r
end -- JSONutil.fetch()



-- Export
local p = { }

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 JSONutil.failsafe( since )  or  ""
end -- p.failsafe()

p.JSONutil = function ()
    -- Module interface
    return JSONutil
end

return p