MediaWiki:Gadget-QuickDiff.js

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/* <nowiki>
    QuickDiff - quickly view any diff link
    Modified to remove Wikia-specific i18n code, relies on [[MediaWiki:Gadget-QDmodal.js]]

    @author OneTwoThreeFall
    @source <https://dev.fandom.com/wiki/QuickDiff>
    @source <https://dev.fandom.com/wiki/MediaWiki:QuickDiff/code.js>
*/

/*jslint browser, long */
/*global jQuery, mediaWiki, dev */

(function ($, mw) {
    "use strict";

    // double-run protection
    if (window.quickDiffLoaded) {
        return;
    }
    window.quickDiffLoaded = true;


    var diffStylesModule = "mediawiki.action.history.diff";
    var modal;
    var special = {};

    // "Special:Diff/12345" and "Special:ComparePages" link detection
    function initSpecialPageStrings() {
        special.diffDefault = mw.util.getUrl("Special:Diff/");
        special.compareDefault = mw.util.getUrl("Special:ComparePages");

        var wiki = mw.config.get("wgDBname");
        var storageKeyDiff = "QuickDiff-specialdiff_" + wiki;
        var storageKeyCompare = "QuickDiff-specialcompare_" + wiki;

        try {
            special.diff = localStorage.getItem(storageKeyDiff);
            special.compare = localStorage.getItem(storageKeyCompare);
        } catch (ignore) {}

        if (special.diff && special.compare) {
            // using stored values - no need for api request
            return;
        }

        $.getJSON(mw.util.wikiScript("api"), {
            action: "parse",
            format: "json",
            prop: "text",
            text: "<span class='diff'>[[Special:Diff/]]</span><span class='compare'>[[Special:ComparePages]]</span>",
            disablepp: "" // note: deprecated in MW 1.26, but needed for older versions
        }).done(function (data) {
            var $parsed = $(data.parse.text["*"]);

            special.diff = $parsed.find(".diff > a").attr("href");
            special.compare = $parsed.find(".compare > a").attr("href");

            try {
                localStorage.setItem(storageKeyDiff, special.diff);
                localStorage.setItem(storageKeyCompare, special.compare);
            } catch (ignore) {}
        });
    }

    function getDiffTitle($diff) {
        var prevTitle = $diff.find("#mw-diff-otitle1 a").attr("title");
        var currTitle = $diff.find("#mw-diff-ntitle1 a").attr("title");

        if (prevTitle && prevTitle !== currTitle) {
            return "Differences between " + prevTitle + " and " + currTitle;
        }

        return "Differences: " + currTitle;
    }

    function loadDiff(url) {
        modal.show({
            loading: true,
            title: !modal.visible && "Loading..."
        });

        // add 'action=render' and 'diffonly' params to save some bytes on each request
        url.extend({
            action: "render",
            diffonly: "1"
        });

        // pass through 'bot' param for rollback links if it's in use on the current page
        if (mw.util.getParamValue("bot")) {
            url.extend({bot: "1"});
        }

        $.when(
            $.get(url.getRelativePath()),
            mw.loader.using(diffStylesModule)
        ).always(function (response) {
            delete url.query.action;
            delete url.query.diffonly;
            delete url.query.bot;

            var data = {
                buttons: [{
                    text: "open link",
                    href: url.toString(),
                    attr: {"data-disable-quickdiff": ""}
                }]
            };
            var $diff;

            if (typeof response[0] === "string") {
                var $content = $(response[0]);
                $diff = $content.filter("table.diff, #mw-rev-deleted-no-diff");

                if (!$diff.length) {
                    // $content is a complete page - see if a diff can be found
                    // needed for diffs from special pages as they ignore action=render URL parameter
                    $diff = $content.find("table.diff");
                }
            }

            if ($diff && $diff.length) {
                data.content = $diff;
                data.hook = "quickdiff.ready";
                data.title = getDiffTitle($diff);
            } else {
                data.content = "Something went wrong while getting the page at " + url.toString() + ".";
            }

            modal.show(data);
        });
    }

    function linkClickHandler(event) {
        // ignore clicks with modifier keys to avoid overriding browser features
        if (event.altKey || event.ctrlKey || event.metaKey || event.shiftKey) {
            return;
        }

        // ignore click if link has "data-disable-quickdiff" attribute set
        if (event.currentTarget.dataset.disableQuickdiff !== undefined) {
            return;
        }

        var url = event.currentTarget.href;

        try {
            url = new mw.Uri(url);
        } catch (ignore) {
            // quit if url couldn't be parsed
            // it wouldn't be a link QuickDiff could handle anyway
            return;
        }

        // cross-domain requests not supported
        if (url.host !== location.hostname) {
            return;
        }

        // no fragment check is to ensure section links/collapsible trigger links on diff pages are ignored
        var hasDiffParam = url.query.diff !== undefined
                && url.fragment === undefined;
        var isSpecialDiffLink = url.path.indexOf(special.diff) === 0
                || url.path.indexOf(special.diffDefault) === 0;
        var isSpecialCompareLink = url.path.indexOf(special.compare) === 0
                || url.path.indexOf(special.compareDefault) === 0;

        if (hasDiffParam || isSpecialDiffLink || isSpecialCompareLink) {
            event.preventDefault();
            loadDiff(url);
        }
    }

    function init() {
        modal = new mw.libs.QDmodal("quickdiff-modal");

        // full screen modal
        mw.util.addCSS("#quickdiff-modal { height: 100%; width: 100% }");

        // diff styles module was renamed in MW 1.28
        if (mw.loader.getState("mediawiki.diff.styles")) {
            diffStylesModule = "mediawiki.diff.styles";
        }

        // attach to body for compatibility with ajax-loaded content
        // also, one attached event handler is better than hundreds!
        $(document.body).on("click.quickdiff", "a[href]", linkClickHandler);

        initSpecialPageStrings();
    }

	init();

    // collect action links (edit, undo, rollback, patrol) and add them to footer
    mw.hook("quickdiff.ready").add(function (modal) {
        // edit/undo links use "mw-rev-head-action" class on Wikia,
        // and "mw-diff-edit" or "-undo" class on MW 1.24+
        var $buttons = modal.$content.find(".diff-ntitle").find(
            ".mw-rev-head-action, .mw-diff-edit, .mw-diff-undo, .mw-rollback-link, .patrollink"
        ).clone();

        // remove text nodes (the brackets around each link)
        $buttons.contents().filter(function (ignore, element) {
            return element.nodeType === 3;
        }).remove();

        $buttons.find("a")
            .addClass("qdmodal-button")
            .attr("target", "_blank");

        modal.$footer.append($buttons);
    });
}(jQuery, mediaWiki));