MediaWiki: Hide pages' tables of contents upon loading.

MediaWiki_hide_TOC.js

/* Begin https://example.org/path/to/wiki/MediaWiki:Common.js */
/* Any JavaScript here will be loaded for all users on every page load. */
/* This file will be included in response to requests like https://example.org/path/to/wiki/index.php?action=raw&smaxage=0&gen=js */

/* Hide the table of contents each time any page is loaded. */

function hideToc() {
    try {
        // Detect whether the page's TOC is displayed.
        if (document.getElementById('toc').getElementsByTagName('ul')[0].style.display != 'none') {
            // Use MW's toggleToc() to hide TOC, change "hide/show" link text, and set cookie.
            toggleToc();
        }
    } catch (exception) {
        // Probably this page doesn't have a TOC.  Ignore the exception to prevent console clutter.
    }
}

// The enclosed code runs only after the page has been loaded and parsed.
window.addEventListener('DOMContentLoaded', function() {
    hideToc();
}, false);

/* End https://example.org/path/to/wiki/MediaWiki:Common.js */