Expand All Images in 4chan Thread Greasemonkey Extension

expand.js

// ==UserScript==
// @name        Expand All Images
// @namespace   zombiearmy.expandimage
// @description Expand all images in a 4chan thread
// @match       *://boards.4chan.org/*
// @match       *://boards.4channel.org/*
// @version     2
// @grant       none
// ==/UserScript==

var expanded = false;

//add expand buttons for desktop
var navlink = document.getElementsByClassName("navLinks desktop");
for(var i = 0; i < navlink.length; i++) {
	navlink[i].innerHTML += " [<a href='javascript:toggleImages()'>Toggle Images</a>] ";
}

//add expand buttons for mobile
navlink = document.getElementsByClassName("navLinks mobile");
for(i = 0; i < navlink.length; i++) {
	navlink[i].innerHTML += '<span class="mobileib button"><a href="javascript:toggleImages()">Expand Images</a></span>';
}

window.toggleImages = function() {
	var thumbs = document.getElementsByClassName("fileThumb");
	if(!expanded) {
		expanded = true;
		for(var i = 0; i < thumbs.length; i++) {
			var img = thumbs[i].getElementsByTagName('img')[0];
			if (img.alt != "File deleted.") {
                                 ImageExpansion.expand(img);
                        }
		}
	}else{
		expanded = false;
		var collapseWebm = document.getElementsByClassName("collapseWebm");
		var expandedWebm = document.getElementsByClassName("expandedWebm");
		while(collapseWebm.length > 0){
			collapseWebm[0].remove();
		}
		while(expandedWebm.length > 0){
			expandedWebm[0].remove();
		}
		for(var i = 0; i < thumbs.length; i++) {
			if(thumbs[i].style.display=="none"){
				thumbs[i].style.display = null;
			}
			var img = thumbs[i].getElementsByTagName('img')[1];
			if (img !== undefined) {
			         ImageExpansion.contract(img);
			}
		}
	}
}

True bookmarklet with the (function(){...})(); IIFE wrapper:
javascript:(function(){var t=document.getElementsByClassName("fileThumb");for(var i=0;i<t.length;i++){ImageExpansion.expand(t[i].getElementsByTagName('img')[0]);}})();

The links are showing on the page, but when I click them in Firefox 58.0.22 nothing happens. The console says ReferenceError: toggleImages is not defined. I've tried messing around but can't find a solution. Any help would be appreciated.

The script would stop if it encountered a deleted image in a thread. Here there is a quick fix:
Edit: Videos weren't collapsing, fixed that too.

window.toggleImages = function() {
	var thumbs = document.getElementsByClassName("fileThumb");
	if(!expanded) {
		expanded = true;
		for(var i = 0; i < thumbs.length; i++) {
			var img = thumbs[i].getElementsByTagName('img')[0];
			if (img.alt != "File deleted.") {
                                 ImageExpansion.expand(img);
                        }
		}
	}else{
		expanded = false;
		var collapseWebm = document.getElementsByClassName("collapseWebm");
		var expandedWebm = document.getElementsByClassName("expandedWebm");
		while(collapseWebm.length > 0){
			collapseWebm[0].remove();
		}
		while(expandedWebm.length > 0){
			expandedWebm[0].remove();
		}
		for(var i = 0; i < thumbs.length; i++) {
			if(thumbs[i].style.display=="none"){
				thumbs[i].style.display = null;
			}
			var img = thumbs[i].getElementsByTagName('img')[1];
			if (img !== undefined) {
			         ImageExpansion.contract(img);
			}
		}
	}
}

Also the the includes should be updated to this:

// @include     *://boards.4chan.org/*
// @include     *://boards.4channel.org/*

Not sure if anyone is still using this in 2022 (I'm not!) but I just updated it with Maurogch's fixes (thank you!!!!) because this page still seems to still come up on google searches, so it might as well be functional :)