closes #6326

public/language/en-GB/admin/manage/categories.json

@@ -65,5 +65,7 @@
 	"alert.find-user": "Find a User",
 	"alert.user-search": "Search for a user here...",
 	"alert.find-group": "Find a Group",
-	"alert.group-search": "Search for a group here..."
+	"alert.group-search": "Search for a group here...",
+	"collapse-all": "Collapse All",
+	"expand-all": "Expand All"
 }

public/src/admin/manage/categories.js

@@ -37,6 +37,20 @@ define('admin/manage/categories', ['vendor/jquery/serializeObject/jquery.ba-seri
 			el.find('i').toggleClass('fa-minus').toggleClass('fa-plus');
 			el.closest('[data-cid]').find('> ul[data-cid]').toggleClass('hidden');
 		});
+
+		$('#collapse-all').on('click', function () {
+			toggleAll(false);
+		});
+
+		$('#expand-all').on('click', function () {
+			toggleAll(true);
+		});
+
+		function toggleAll(expand) {
+			var el = $('.categories .toggle');
+			el.find('i').toggleClass('fa-minus', expand).toggleClass('fa-plus', !expand);
+			el.closest('[data-cid]').find('> ul[data-cid]').toggleClass('hidden', !expand);
+		}
 	};
 
 	Categories.throwCreateModal = function () {

src/views/admin/manage/categories.tpl

@@ -1,3 +1,5 @@
+<button id="collapse-all" class="btn btn-default">[[admin/manage/categories:collapse-all]]</button> <button id="expand-all" class="btn btn-default">[[admin/manage/categories:expand-all]]</button>
+<hr/>
 <div class="categories"></div>
 
 <button data-action="create" class="floating-button mdl-button mdl-js-button mdl-button--fab mdl-js-ripple-effect mdl-button--colored">