MediaWiki:Gadget-AddArchiveCategory.js

Note: After saving, you may have to bypass your browser's cache to see the changes.

• Firefox / Safari: Hold Shift while clicking Reload, or press either Ctrl-F5 or Ctrl-R (⌘-R on a Mac)
• Google Chrome: Press Ctrl-Shift-R (⌘-Shift-R on a Mac)
• Internet Explorer / Edge: Hold Ctrl while clicking Refresh, or press Ctrl-F5
• Opera: Go to Menu → Settings (Opera → Preferences on a Mac) and then to Privacy & security → Clear browsing data → Cached images and files.

mw.loader.using(['mediawiki.util', 'mediawiki.api'], function () {
    var api = new mw.Api();

    function addCategory() {
        var text = `[[${"Category"}:${"Archived}]]`;
        api.edit(mw.config.get('wgPageName'), function (revision) {
            return {
                text: revision.content + '\n' + text,
                summary: 'Adding category ' + categoryName,
                minor: true
            };
        }).then(function () {
            window.location.reload(); // Reload the page to see the new category
        }, function (e) {
            mw.notify('Failed to add category: ' + e);
        });
    }

    $(document).ready(function () {
        mw.util.addPortletLink(
            'p-tb', // sidebar section (portlet id).
            '#',    // href for the link (will trigger javascript instead)
            'Add Archived Category', // link text.
            'ca-add-archive-category', // unique identifier for the link.
            'Add a category to this page' // tooltip text.
        );
        $('#ca-add-archive-category').click(function (e) {
            e.preventDefault();
            addCategory();
        });
    });
});