Jump to content

User:Enterprisey/fancy-diffs.js

From Wikipedia, the free encyclopedia
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Note: After saving, you have to bypass your browser's cache to see the changes. Google Chrome, Firefox, Microsoft Edge and Safari: Hold down the ⇧ Shift key and click the Reload toolbar button. For details and instructions about other browsers, see Wikipedia:Bypass your cache.
// vim: ts=4 sw=4 et ai
( function () {
    var api;
    var DC_CLS = ' class="diffchange diffchange-inline"'; // the CSS classes for the diffchange (<ins>/<del>) spans

    function processText( text, pageName ) {
        var chunks = [];

        // Types for chunks (I really should've called them "tokens")
        var TEXT = 0;
        var INS_START = 1;
        var INS_END = 2;
        var DEL_START = 3;
        var DEL_END = 4;
        var A_START = 5;
        var A_END = 6;
        var EXPAND = 7;

        // Throughout, "ins or del" is abbreviated as "change" or "chg"
        var CHG_RGX = /<(ins|del) class="diffchange diffchange-inline">([^<]+?)($|<\/\1>)/g;
        var lastChgEnd = 0;
        var chgMatch;
        var justText = "";
        var firstTextSegment;
        var isIns;
        do {
            chgMatch = CHG_RGX.exec( text );
            if( chgMatch ) {
                firstTextSegment = text.substring( lastChgEnd, chgMatch.index );
                if( firstTextSegment.length ) {
                    chunks.push( { ty: TEXT, txt: firstTextSegment, idx: justText.length } );
                    justText += firstTextSegment;
                }
                isIns = chgMatch[1] === "ins"; chunks.push( { ty: isIns ? INS_START : DEL_START } );
                chunks.push( { ty: TEXT, txt: chgMatch[2], idx: justText.length } );
                chunks.push( { ty: isIns ? INS_END : DEL_END } );
                justText += chgMatch[2];
                lastChgEnd = chgMatch.index + chgMatch[0].length;
            }
        } while( chgMatch );
        if( lastChgEnd <= text.length - 1 ) {
            chunks.push( { ty: TEXT, txt: text.substring( lastChgEnd ), idx: justText.length } );
            justText += text.substring( lastChgEnd );
        }

        var markupHandlers = [
            {
                regex: /\[\[(.+?)(?:\|.+?)?\]\]/g,
                handler: function ( match ) {
                    var linkTarget = match[1];
                    if( linkTarget.indexOf( "#" ) === 0 ) {
                        linkTarget = pageName + linkTarget;
                    }
                    var result = [
                        { ty: A_START, url: mw.util.getUrl( linkTarget ) },
                        { ty: TEXT, txt: match[0] },
                        { ty: A_END }
                    ];

                    if( linkTarget.indexOf( "File:" ) === 0 || linkTarget.indexOf( "Image:" ) === 0 ) {
                        result.push( { ty: EXPAND, expandTy: "img", data: linkTarget.replace( /"/g, "&quot;" ) } );
                    }

                    return result;
                }
            },
            {
                regex: /\{\{(.+?)(?:\|.+?)?\}\}/g,
                handler: function ( match ) {
                    var name = match[1],
                        fullName = name;
                    if( name.indexOf( "#" ) === 0 ) {
                        fullName = name.replace( /^#invoke:/, "Module:" );
                    } else if( name.indexOf( ":" ) < 0 ) {
                        fullName = "Template:" + name;
                    }

                    return [
                        { ty: TEXT, txt: "{{" }, // "}}" pour one out for vim's syntax highlighter
                        { ty: A_START, url: mw.util.getUrl( fullName ) },
                        { ty: TEXT, txt: match[1] },
                        { ty: A_END },
                        { ty: TEXT, txt: match[0].substring( 2 + name.length ) }
                    ];
                }
            },
            {
                regex: /(?:(?:https|http|gopher|irc|ircs|ftp|news|nnttp|worldwind|telnet|svn|git|mms):\/\/|mailto:)([!#$&-;=?-\[\]_a-z~]|%[0-9a-fA-F]{2})+/g,
                handler: function ( match ) {
                    var url = match[0];
                    if( match.input[ match.index - 1 ] === "[" && url[url.length - 1] === "]" ) {
                        url = url.substring( 0, url.length - 1 );
                    }
                    return [
                        { ty: A_START, url: url },
                        { ty: TEXT, txt: url },
                        { ty: A_END },
                    ];
                }
            }
        ];

        // Definitely among the trickiest code I've written for a user
        // script to date. The version that kept detailed track of
        // string indices was much worse, trust me!
        for( var handlerIdx = 0; handlerIdx < markupHandlers.length; handlerIdx++ ) {
            var regex = markupHandlers[handlerIdx].regex,
                handler = markupHandlers[handlerIdx].handler;
            var match;
            do {
                match = regex.exec( justText );
                if( match ) {
                    var replacementChunks = handler( match );

                    // Locate the start and end of `match` in `chunks`
                    var startChunkIdx = -1,
                        endChunkIdx = -1;
                    for( var chunkIdx = 0; chunkIdx < chunks.length; chunkIdx++ ) {
                        if( chunks[chunkIdx].ty !== TEXT ) {
                            continue;
                        } else if( startChunkIdx < 0 ) {
                            if( ( chunks[chunkIdx].idx + chunks[chunkIdx].txt.length ) > match.index ) {
                                startChunkIdx = chunkIdx;
                            }
                        }
                        if( ( startChunkIdx >= 0 ) && chunks[chunkIdx].idx >= ( match.index + match[0].length ) ) {
                            endChunkIdx = chunkIdx;
                            break;
                        }
                    }

                    // Edge-case handling for the start/end chunk locator
                    if( startChunkIdx < 0 ) {
                        console.error( "whoops" );
                    } else if( endChunkIdx < 0 ) {
                        endChunkIdx = chunks.length - 1;
                    } else {
                        endChunkIdx--;
                    }
                    while( chunks[endChunkIdx].ty !== TEXT ) endChunkIdx--;

                    // Split the start and end chunks, so we can cleanly insert the A_START and A_END
                    var startChunk = chunks[startChunkIdx];
                    var idxInStartChunk = match.index - startChunk.idx;
                    if( idxInStartChunk > 0 && idxInStartChunk < ( startChunk.txt.length - 1 ) ) {
                        chunks.splice( startChunkIdx, 1,
                            { ty: TEXT, txt: startChunk.txt.substring( 0, idxInStartChunk ), idx: startChunk.idx },
                            { ty: TEXT, txt: startChunk.txt.substring( idxInStartChunk ), idx: startChunk.idx + idxInStartChunk }
                        );
                        startChunkIdx++;
                        startChunk = chunks[startChunkIdx];
                        endChunkIdx++;
                    }

                    var endChunk = chunks[endChunkIdx];
                    var idxInEndChunk = match.index + match[0].length - endChunk.idx;
                    if( idxInEndChunk > 0 && idxInEndChunk < ( endChunk.txt.length - 1 ) ) {
                        chunks.splice( endChunkIdx, 1,
                            { ty: TEXT, txt: endChunk.txt.substring( 0, idxInEndChunk ), idx: endChunk.idx },
                            { ty: TEXT, txt: endChunk.txt.substring( idxInEndChunk ), idx: endChunk.idx + idxInEndChunk }
                        );
                    }

                    // Make sure the new text chunks have correct idx's set
                    var replacementTextLength = 0;
                    for( var i = 0; i < replacementChunks.length; i++ ) {
                        if( replacementChunks[i].ty === TEXT ) {
                            replacementChunks[i].idx = startChunk.idx + replacementTextLength;
                            replacementTextLength += replacementChunks[i].txt.length;
                        }
                    }

                    // Insert the new chunks in place of the old ones - keeping all the formatting intact!
                    var newChunks = [];
                    var newTextLen = 0;
                    var existingChunks = chunks.slice( startChunkIdx, endChunkIdx + 1 );
                    var replIdx = 0, existIdx = 0; // counters in `replacementChunks` & `existingChunks` respectively
                    var replInnerIdx = 0, existInnerIdx = 0; // indices into text chunks
                    while( true ) {

                        // Non-TEXT chunks are formatting/control and always get pushed
                        while( replacementChunks[replIdx] && ( replacementChunks[replIdx].ty !== TEXT ) ) {
                            newChunks.push( replacementChunks[replIdx] );
                            replIdx++;
                        }
                        while( existingChunks[existIdx] && ( existingChunks[existIdx].ty !== TEXT ) ) {
                            newChunks.push( existingChunks[existIdx] );
                            existIdx++;
                        }

                        if( newTextLen >= match[0].length ) {
                            break;
                        }

                        // Pick the shorter chunk, so as not to miss any formatting.
                        var replEndIdx = ( replIdx < replacementChunks.length )
                            ? ( replacementChunks[replIdx].idx + replacementChunks[replIdx].txt.length )
                            : Infinity;
                        var existEndIdx = ( existIdx < existingChunks.length )
                            ? ( existingChunks[existIdx].idx + existingChunks[existIdx].txt.length )
                            : Infinity;
                        var usingRepl = replEndIdx <= existEndIdx;
                        if( usingRepl ) {
                            var newText = replacementChunks[replIdx].txt.substring( replInnerIdx );
                            newChunks.push( { ty: TEXT, txt: newText, idx: startChunk.idx + newTextLen } );
                            newTextLen += newText.length;
                            replInnerIdx = 0;
                            while( true ) {
                                replIdx++;
                                if( !replacementChunks[replIdx] || ( replacementChunks[replIdx].ty === TEXT ) ) break;
                                newChunks.push( replacementChunks[replIdx] );
                            }
                            existInnerIdx += newText.length;
                            for( ; existIdx < existingChunks.length; existIdx++ ) {
                                if( existingChunks[existIdx].ty !== TEXT ) {
                                    newChunks.push( existingChunks[existIdx] );
                                } else if( existInnerIdx >= existingChunks[existIdx].txt.length ) {
                                    existInnerIdx -= existingChunks[existIdx].txt.length;
                                } else {
                                    break;
                                }
                            }
                        } else {
                            var newText = existingChunks[existIdx].txt.substring( existInnerIdx );
                            newChunks.push( { ty: TEXT, txt: newText, idx: startChunk.idx + newTextLen } );
                            newTextLen += newText.length;
                            existInnerIdx = 0;
                            while( true ) {
                                existIdx++;
                                if( !existingChunks[existIdx] || ( existingChunks[existIdx].ty === TEXT ) ) break;
                                newChunks.push( existingChunks[existIdx] );
                            }
                            replInnerIdx += newText.length;
                            for( ; replIdx < replacementChunks.length; replIdx++ ) {
                                if( replacementChunks[replIdx].ty !== TEXT ) {
                                    newChunks.push( replacementChunks[replIdx] );
                                } else if( replInnerIdx >= replacementChunks[replIdx].txt.length ) {
                                    replInnerIdx -= replacementChunks[replIdx].txt.length;
                                } else {
                                    break;
                                }
                            }
                        }
                    }

                    // Now, splice the new chunks in place of the old ones
                    var spliceArgs = [ startChunkIdx, endChunkIdx - startChunkIdx + 1 ].concat( newChunks );
                    Array.prototype.splice.apply( chunks, spliceArgs );
                }
            } while( match );
        }

        // Write out chunks into text
        var html = "";
        var activeTag = "";
        for( var i = 0; i < chunks.length; i++ ) {
            var chunk = chunks[i];
            switch( chunk.ty ) {
                case TEXT: html += chunk.txt; break;
                case INS_START: html += "<ins" + DC_CLS + ">"; activeTag = "ins"; break;
                case INS_END: html += "</ins>"; activeTag = ""; break;
                case DEL_START: html += "<del" + DC_CLS + ">"; activeTag = "del"; break;
                case DEL_END: html += "</del>"; activeTag = ""; break;
                case A_START:
                    if( activeTag ) {
                        html += "</" + activeTag + ">";
                    }
                    html += "<a class='fancy-diffs' href=\"" + chunk.url + "\">";
                    if( activeTag ) {
                        html += "<" + activeTag + DC_CLS + ">";
                    }
                    break;
                case A_END:
                    if( activeTag ) {
                        html += "</" + activeTag + ">";
                    }
                    html += "</a>";
                    if( activeTag ) {
                        html += "<" + activeTag + DC_CLS + ">";
                    }
                    break;
                case EXPAND:
                    html += '<span class="fd-expand" data-' + chunk.expandTy + '="' + chunk.data + '">(show)</span>';
                    break;
            }
        }

        return html;
    }

    function processDiff( diffTable ) {
        if( !diffTable.querySelector ) {

            // Assume diffTable is a jQuery object
            diffTable = diffTable.get( 0 );
        }

        if( diffTable.getElementsByClassName( "fancy-diffs" ).length > 0 ) {

            // We already ran on this diff
            return;
        }

        // Determine page name, because processText wants it
        var pageName;
        switch( mw.config.get( "wgCanonicalSpecialPageName" ) ) {
            case "Contributions":
                pageName = diffTable.parentNode.querySelector( "a.mw-contributions-title" ).textContent;
                break;
            case "Watchlist":
                pageName = diffTable.previousElementSibling.querySelector( "a.mw-changeslist-title" ).textContent;
                break;
            default:
                pageName = mw.config.get( "wgPageName" );
                break;
        }

        var rows = diffTable.querySelectorAll( "tr" );
rowLoop:
        for( var rowIdx = 0, numRows = rows.length; rowIdx < numRows; rowIdx++ ) {
            var row = rows[rowIdx];
            if( row.tagName.toLowerCase() === "colgroup" ) {
                return;
            }
            if( row.querySelector( "a" ) ) {
                continue;
            }
            for( var cellIdx = 0, numCells = row.children.length; cellIdx < numCells; cellIdx++ ) {
                var td = row.children[cellIdx];
                if( td.className.indexOf( "diff-context" ) >= 0 ) {
                    if( td.children && td.children.length ) {
                        var text = processText( td.children[0].innerHTML, pageName );
                        td.children[0].innerHTML = text;
                        row.children[cellIdx + 2].innerHTML = text;
                        continue rowLoop;
                    }
                } else if( ( td.className.indexOf( "diff-addedline" ) >= 0 ) ||
                        ( td.className.indexOf( "diff-deletedline" ) >= 0 ) ) {
                    if( td.children && td.children.length ) {
                        td.children[0].innerHTML = processText( td.children[0].innerHTML, pageName );
                    }
                }
            }
        }

        var expandSpans = diffTable.querySelectorAll( "span.fd-expand" );
        for( var spanIdx = 0, numSpans = expandSpans.length; spanIdx < numSpans; spanIdx++ ) {
            var span = expandSpans[spanIdx];
            span.addEventListener( "click", function () {
                if( !this.nextElementSibling || this.nextElementSibling.tagName.toLowerCase() !== "div" || this.nextElementSibling.className !== "fd-img" ) {
                    api.get( {
                        action: "query",
                        titles: this.dataset.img,
                        prop: "imageinfo",
                        iiprop: "url"
                    } ).done( function ( data ) {
                        if( data.query && data.query.pages ) {
                            var url = data.query.pages[ Object.keys( data.query.pages )[0] ].imageinfo[0].url;
                            var div = document.createElement( "div" );
                            div.className = "fd-img";
                            var img = document.createElement( "img" );
                            img.className = "fancy-diffs";
                            img.src = url;
                            img.style["max-width"] = "100%";
                            div.appendChild( img );
                            this.parentNode.insertBefore( div, this.nextSibling );
                        }
                    }.bind( this ) );
                    this.textContent = "(hide)";
                } else {
                    if( this.nextElementSibling.style.display === "none" ) {
                        this.nextElementSibling.style.display = "";
                        this.textContent = "(hide)";
                    } else {
                        this.nextElementSibling.style.display = "none";
                        this.textContent = "(show)";
                    }
                }
            } );
        }
    }

    $.when(
        $.ready,
        mw.loader.using( [ "mediawiki.api", "mediawiki.util" ] )
    ).then( function () {
        var table = document.querySelector( "table.diff" );
        api = new mw.Api();
        mw.util.addCSS( ".fd-expand { cursor: pointer; text-decoration: underline; background-color: #faf3; }" );
        if( table ) {
            processDiff( table );
        }
        mw.hook( "wikipage.diff" ).add( processDiff );
        mw.hook( "new-diff-table" ).add( processDiff );
        mw.hook( "diff-update" ).add( processDiff );
    } );
} )();