Common.js

Note: After publishing, 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: Press Ctrl-F5.
/* Any JavaScript here will be loaded for all users on every page load. */

/* Navigation Popups */
/* Currently Disabled
mw.loader.load('/load.php?modules=ext.gadget.Navigation_popups');
window.popupAdminLinks = false;
window.popupActionsMenu = false;
window.popupStructure = 'lite';
window.popupSubpopups = false;
window.popupSummaryData = false;
*/

function randomPageImage( category ) {
	params = {
	        action: 'query',
	        list: 'categorymembers',
	        cmtitle: 'Category:' + category,
	        cmprop: 'ids',
	        cmtype: 'page',
	        cmlimit: '5000',
	        format: 'json'
    },
    api = new mw.Api();
	
	return new Promise(function(resolve,reject) { 
		api.get( params ).done( function ( data ) {
		    var pages = data.query.categorymembers,
		        page,
		        cat_random = Math.floor(Math.random() * pages.length),
		        id_random = pages[cat_random].pageid;
		
		    var paramsPI = {
		        action: 'query',
		        prop: 'pageimages',
		        pageids: id_random,
		        piprop: 'original',
		        format: 'json'
		    };
		    api.get( paramsPI ).done( function (data ) {
		        resolve(data.query.pages[id_random].original);
		    });
		} );
	});
}

$(document).ready(function() {
	var pagename = mw.config.get('wgPageName'),
		namespace = mw.config.get('wgNamespaceNumber');
	// var indicator = document.querySelectorAll(".mw-indicators");
	// var indicator1 = indicator[0];
	
	// if (indicator1.childNodes.length !== 1) {document.getElementById("tagline").innerHTML = indicator1.innerHTML;}
	
	/*== Hides the actions button and indicators while in the Visual editor ==*/
	
	mw.hook( 've.activationComplete' ).add( function () {
		$('.content .top').hide();
	});
	
	mw.hook( 've.deactivationComplete' ).add( function () {
			$('.content .top').show();
	});
	
	/*== Dogcraft.net topbar: Automatically enabled to display the Dogcraft.net topbar on the Help Resources(WIP) and Rules pages. (moved from gadget) ==*/
	$(document).ready(function() {
		if (mw.config.get('wgPageName') === "Rules" || mw.config.get('wgPageName') === "Help_Resources")
		{
			$('.nav .nav-title a span').text('Dogcraft');
			$('#wikiNav').removeClass('expanded');
		}
	});
	
	/*== Shows edit button on Rules and Help Resources for those who can edit it ==*/
	if (pagename === 'Rules' || pagename === 'Help_Resources') {
		if (mw.config.get('wgIsProbablyEditable')) {
			$('#wikiActions').show();
		}
	}
	
	/*= Top header banner =*/
	if (namespace === 14 || namespace === 3004) {
		var headbanner = document.getElementById("headbanner");
		if (headbanner) {
			var firstHeading = document.getElementById("firstHeading");
			if (headbanner.hasAttribute("title")) { 
				if (headbanner.title == "auto") {
					randomPageImage(pagename.split(":")[1].split("/")[0]).then(function(result) {
						firstHeading.style.setProperty('--banner-padding', "300px");
						firstHeading.style.setProperty('--banner-image', 'url(' + result.source + ')');
					});
				} else {
					firstHeading.style.setProperty('--banner-padding', headbanner.title);
					firstHeading.style.setProperty('--banner-image', 'url(' + headbanner.textContent + ')');
				}
			}
			firstHeading.classList.add('banner');
			$("#siteSub").prepend($("#main > .content > .top"));
			document.body.classList.add("has-banner-img");
		}
		
		/** custom category page marker class 
		* added to firstHeading because requesting the page <body> (which normally has marker classes) on every category page load is 
		* not a good idea - its the parent for the whole page. The firstHeading is siblings with every other 1st child of the page content,
		* which includes the div.top on pages with a top banner image set. (But this can be used on non-bannered cat pages as well)
		*/
		if ( mw.config.get('wgCategories').includes('Custom category pages') ) {
			document.getElementById("firstHeading").classList.add("category-custom");
		}
	}

});
MediaWiki

Common.js
