Adds loading to improve UX

app/assets/javascripts/mini_pipeline_graph_dropdown.js.es6

@@ -18,31 +18,34 @@
   class MiniPipelineGraph {
     constructor({ container }) {
       this.container = container;
+      this.dropdownListSelector = '.js-builds-dropdown-container';
       this.getBuildsList = this.getBuildsList.bind(this);
 
       this.bindEvents();
     }
 
     /**
-     * Adds an removes the event listener.
-     * TODO: Remove jQuery when we have a way to handle events properly.
+     * Adds and removes the event listener.
      */
     bindEvents() {
-      $(this.container).off('click', 'button.js-builds-dropdown-button', this.getBuildsList);
-      $(this.container).on('click', 'button.js-builds-dropdown-button', this.getBuildsList);
+      const dropdownButtonSelector = 'button.js-builds-dropdown-button';
+
+      $(this.container).off('click', dropdownButtonSelector, this.getBuildsList);
+      $(this.container).on('click', dropdownButtonSelector, this.getBuildsList);
     }
 
     /**
-     * For the clicked stage, renders the received html in the sibiling
-     * element with the `js-builds-dropdown-container` clas
+     * For the clicked stage, renders the given data in the dropdown list.
      *
-     * @param  {Element} stageContainer
+     * @param  {HTMLElement} stageContainer
      * @param  {Object} data
      */
     renderBuildsList(stageContainer, data) {
-      const dropdownContainer = stageContainer.parentElement.querySelector('.js-builds-dropdown-container');
+      const dropdownContainer = stageContainer.parentElement.querySelector(
+        `${this.dropdownListSelector} .js-builds-dropdown-list`,
+      );
 
-      dropdownContainer.innerHTML = data.html;
+      dropdownContainer.innerHTML = data;
     }
 
     /**
@@ -58,10 +61,29 @@
         dataType: 'json',
         type: 'GET',
         url: endpoint,
-        success: data => this.renderBuildsList(e.currentTarget, data),
+        beforeSend: () => {
+          this.renderBuildsList(e.currentTarget, '');
+          this.toggleLoading(e.currentTarget);
+        },
+        success: (data) => {
+          this.toggleLoading(e.currentTarget);
+          this.renderBuildsList(e.currentTarget, data.html);
+        },
         error: () => new Flash('An error occurred while fetching the builds.', 'alert'),
       });
     }
+
+    /**
+     * Toggles the visibility of the loading icon.
+     *
+     * @param  {HTMLElement} stageContainer
+     * @return {type}
+     */
+    toggleLoading(stageContainer) {
+      stageContainer.parentElement.querySelector(
+        `${this.dropdownListSelector} .js-builds-dropdown-loading`,
+      ).classList.toggle('hidden');
+    }
   }
 
   window.gl = window.gl || {};

app/assets/stylesheets/pages/pipelines.scss

@@ -753,14 +753,20 @@
     margin: 0;
   }
 
+  .builds-dropdown-loading {
+    margin: 10px auto;
+    width: 18px;
+  }
+
   .grouped-pipeline-dropdown {
     right: -172px;
     top: 23px;
-  }
+    min-height: 191px;
 
-  .grouped-pipeline-dropdown a {
+    a {
       color: $gl-text-color-light;
     }
+  }
 
   .arrow-up {
     &::before,

app/views/projects/ci/pipelines/_pipeline.html.haml

@@ -53,13 +53,19 @@
         .stage-container.mini-pipeline-graph
           - if hasMultipleBuilds
             .dropdown.inline.build-content
-              %button.has-tooltip.builds-dropdown.js-builds-dropdown-button{ type: 'button', data: { toggle: 'dropdown', title: tooltip, "stage-endpoint" => stage_namespace_project_pipeline_path(pipeline.project.namespace, pipeline.project, pipeline, stage: stage.name)}}
+              %button.has-tooltip.builds-dropdown.js-builds-dropdown-button{ type: 'button', data: { toggle: 'dropdown', title: tooltip, placement: 'top', "stage-endpoint" => stage_namespace_project_pipeline_path(pipeline.project.namespace, pipeline.project, pipeline, stage: stage.name)}}
                 %span{ class: klass }
                   %span.mini-pipeline-graph-icon-container
                     %span{ class: icon_status_klass }= custom_icon(icon_status)
                     = icon('caret-down', class: 'dropdown-caret')
 
-              %div.js-builds-dropdown-container
+              .js-builds-dropdown-container
+                .dropdown-menu.grouped-pipeline-dropdown
+                  .arrow-up
+                  .js-builds-dropdown-list
+
+                  .js-builds-dropdown-loading.builds-dropdown-loading.hidden
+                    %span.fa.fa-spinner.fa-spin
           - else
             - if detailed_status.has_details?
               = link_to detailed_status.details_path, class: klass, title: tooltip do

app/views/projects/pipelines/_stage.html.haml

-.dropdown-menu.grouped-pipeline-dropdown
-  .arrow-up
-    %ul
+%ul
   - @stage.statuses.each do |status|
     %li.dropdown-build
       = render 'ci/status/graph_badge', subject: status