Add `attributes` option to the Modal.open method. Closes #2592

src/modal_dialog/index.js

@@ -87,12 +87,13 @@ export default () => {
      * @param {Object} [opts={}] Options
      * @param {String|HTMLElement} [opts.title] Title to set for the modal
      * @param {String|HTMLElement} [opts.content] Content to set for the modal
+     * @param {Object} [opts.attributes] Updates the modal wrapper with custom attributes
      * @return {this}
      */
     open(opts = {}) {
       opts.title && this.setTitle(opts.title);
       opts.content && this.setContent(opts.content);
-      modal.show();
+      modal.show(opts);
       return this;
     },
 

src/modal_dialog/view/ModalView.js

@@ -115,19 +115,28 @@ export default Backbone.View.extend({
    * Show modal
    * @private
    * */
-  show() {
+  show(opts = {}) {
     this.model.set('open', 1);
+    this.updateAttr(opts.attributes);
+  },
+
+  updateAttr(attr) {
+    const { pfx, $el, el } = this;
+    const currAttr = [].slice.call(el.attributes).map(i => i.name);
+    $el.removeAttr(currAttr.join(' '));
+    $el.attr({
+      ...(attr || {}),
+      class: `${pfx}container ${(attr && attr.class) || ''}`.trim()
+    });
   },
 
   render() {
     const el = this.$el;
-    const pfx = this.pfx;
-    const ppfx = this.ppfx;
     const obj = this.model.toJSON();
     obj.pfx = this.pfx;
     obj.ppfx = this.ppfx;
     el.html(this.template(obj));
-    el.attr('class', `${pfx}container`);
+    this.updateAttr();
     this.updateOpen();
     return this;
   }