Issue #2804639 by tedbow, drpal, catch: Offcanvas dialog width not respected

core/modules/outside_in/js/outside_in.js

@@ -186,7 +186,11 @@
           // @todo Move logic for data-dialog-renderer attribute into ajax.js
           //   https://www.drupal.org/node/2784443
           instance.options.url = instance.options.url.replace(search, replace);
-          instance.options.data.dialogOptions = {outsideInActiveEditableId: $(instance.element).parents('.outside-in-editable').attr('id')};
+          // Check to make sure existing dialogOptions aren't overridden.
+          if (!('dialogOptions' in instance.options.data)) {
+            instance.options.data.dialogOptions = {};
+          }
+          instance.options.data.dialogOptions.outsideInActiveEditableId = $(instance.element).parents('.outside-in-editable').attr('id');
           instance.progress = {type: 'fullscreen'};
         });
     }

core/modules/outside_in/tests/modules/offcanvas_test/src/Controller/TestController.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\offcanvas_test\Controller;
 
+use Drupal\Component\Serialization\Json;
 use Drupal\Core\Url;
 
 /**
@@ -66,6 +67,9 @@ public function linksDisplay() {
           'class' => ['use-ajax'],
           'data-dialog-type' => 'dialog',
           'data-dialog-renderer' => 'offcanvas',
+          'data-dialog-options' => Json::encode([
+            'width' => 555,
+          ]),
         ],
         '#attached' => [
           'library' => [

core/modules/outside_in/tests/src/FunctionalJavascript/OffCanvasTest.php

@@ -52,10 +52,13 @@ public function testOffCanvasLinks() {
         $tray_text = $offcanvas_tray->findById('drupal-offcanvas')->getText();
         $this->assertEquals("Thing $link_index says hello", $tray_text);
 
-        // Check no title behavior.
         if ($link_index == '2') {
+          // Check no title behavior.
           $web_assert->elementExists('css', '.ui-dialog-empty-title');
           $this->assertEquals('', $header_text);
+
+          $style = $page->find('css', '.ui-dialog-offcanvas')->getAttribute('style');
+          self::assertTrue(strstr($style, 'width: 555px;') !== FALSE, 'Dialog width respected.');
         }
         else {
           // Check that header is correct.