Plugin API for label score updates

Plugin may use following API to receive saved label updates:

``` js
plugin.changeMetadata().onLabelsChanged(
    labels => console.log(labels));
```

Feature: Issue 820117
Change-Id: Id428606db25086cfdf5a5b420e34777cc8b27303

Documentation/pg-plugin-change-metadata-api.txt

@@ -0,0 +1,16 @@
+= Gerrit Code Review - Change metadata plugin API
+
+This API is provided by
+link:pg-plugin-dev.html#change-metadata[plugin.changeMetadata()] and provides
+interface for customization and data updates of change metadata.
+
+== onLabelsChanged
+`changeMetadataApi.onLabelsChanged(callback)`
+
+.Params
+- *callback* function that's executed when labels changed on the server.
+Callback receives labels with scores applied to the change, map of the label
+names to link:rest-api-changes.html#label-info[LabelInfo] entries
+
+.Returns
+- `GrChangeMetadataApi` for chaining.

Documentation/pg-plugin-dev.txt

@@ -341,6 +341,15 @@ screen.
 
 Deprecated. Use link:#plugin-settings[`plugin.settings()`] instead.
 
+=== changeMetadata
+`plugin.changeMetadata()`
+
+.Params:
+- none
+
+.Returns:
+- Instance of link:pg-plugin-change-metadata-api.html[GrChangeMetadataApi].
+
 === theme
 `plugin.theme()`
 

Documentation/pg-plugin-endpoints.txt

@@ -69,6 +69,11 @@ link:rest-api-changes.html#change-info[ChangeInfo]
 current revision displayed, an instance of
 link:rest-api-changes.html#revision-info[RevisionInfo]
 
+* `labels`
++
+labels with scores applied to the change, map of the label names to
+link:rest-api-changes.html#label-info[LabelInfo] entries
+
 === robot-comment-controls
 The `robot-comment-controls` extension point is located inside each comment
 rendered on the diff page, and is only visible when the comment is a robot
@@ -118,4 +123,4 @@ This endpoint wraps the textarea in the reply dialog.
 This endpoint decorator wraps the voting buttons in the reply dialog.
 
 === header-title
-This endpoint wraps the title-text in the application header.
+This endpoint wraps the title-text in the application header.

polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata-it_test.html

@@ -29,7 +29,7 @@ limitations under the License.
 
 <test-fixture id="element">
   <template>
-    <gr-change-metadata></gr-change-metadata>
+    <gr-change-metadata mutable="true"></gr-change-metadata>
   </template>
 </test-fixture>
 
@@ -51,20 +51,42 @@ limitations under the License.
       'section.topic',
     ];
 
+    const labels = {
+      CI: {
+        all: [
+          {value: 1, name: 'user 2', _account_id: 1},
+          {value: 2, name: 'user '},
+        ],
+        values: {
+          ' 0': 'Don\'t submit as-is',
+          '+1': 'No score',
+          '+2': 'Looks good to me',
+        },
+      },
+    };
+
     const getStyle = function(selector, name) {
       return window.getComputedStyle(
           Polymer.dom(element.root).querySelector(selector))[name];
     };
 
+    function createElement() {
+      const element = fixture('element');
+      element.change = {labels, status: 'NEW'};
+      element.revision = {};
+      return element;
+    }
+
     setup(() => {
       sandbox = sinon.sandbox.create();
+      stub('gr-rest-api-interface', {
+        getConfig() { return Promise.resolve({}); },
+        getLoggedIn() { return Promise.resolve(false); },
+        deleteVote() { return Promise.resolve({ok: true}); },
+      });
       stub('gr-change-metadata', {
         _computeShowLabelStatus() { return true; },
         _computeShowReviewersByState() { return true; },
-        ready() {
-          this.change = {labels: [], status: 'NEW'};
-          this.serverConfig = {};
-        },
       });
     });
 
@@ -76,7 +98,7 @@ limitations under the License.
 
     suite('by default', () => {
       setup(done => {
-        element = fixture('element');
+        element = createElement();
         flush(done);
       });
 
@@ -99,7 +121,7 @@ limitations under the License.
             ],
           },
         };
-        element = fixture('element');
+        element = createElement();
         const importSpy = sandbox.spy(element.$.externalStyle, '_import');
         Gerrit.awaitPluginsLoaded().then(() => {
           Promise.all(importSpy.returnValues).then(() => {
@@ -114,5 +136,38 @@ limitations under the License.
         });
       }
     });
+
+    suite('label updates', () => {
+      let plugin;
+      let labelChangeStub;
+
+      setup(done => {
+        Gerrit.install(p => plugin = p, '0.1',
+            new URL('test/plugin.html?' + Math.random(),
+                    window.location.href).toString());
+        sandbox.stub(Gerrit, '_arePluginsLoaded').returns(true);
+        Gerrit._resolveAllPluginsLoaded();
+        element = createElement();
+        sandbox.stub(element, '_computeCanDeleteVote').returns(true);
+
+        labelChangeStub = sandbox.stub();
+        plugin.changeMetadata().onLabelsChanged(labelChangeStub);
+        flush(done);
+      });
+
+      test('labels changed callback', done => {
+        assert.equal(labelChangeStub.callCount, 1);
+        assert.isTrue(labelChangeStub.calledWithExactly(labels));
+        assert.equal(labelChangeStub.args[0][0]['CI'].all.length, 2);
+        MockInteractions.tap(Polymer.dom(element.root).querySelector(
+            'gr-account-chip').$.remove);
+        // Wait for fake rest API response.
+        flush(() => {
+          assert.equal(labelChangeStub.callCount, 2);
+          assert.equal(labelChangeStub.args[1][0]['CI'].all.length, 1);
+          done();
+        });
+      });
+    });
   });
 </script>

polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata.html

@@ -316,12 +316,12 @@ limitations under the License.
         </section>
       </template>
       <template is="dom-repeat"
-          items="[[_computeLabelNames(change.labels)]]" as="labelName">
+          items="[[_computeLabelNames(labels)]]" as="labelName">
         <section>
           <span class="title">[[labelName]]</span>
           <span class="value">
             <template is="dom-repeat"
-                items="[[_computeLabelValues(labelName, change.labels.*)]]"
+                items="[[_computeLabelValues(labelName, labels.*)]]"
                 as="label">
               <div class="labelValueContainer">
                 <span>
@@ -379,6 +379,7 @@ limitations under the License.
         </span>
       </section>
       <gr-endpoint-decorator name="change-metadata-item">
+        <gr-endpoint-param name="labels" value="[[labels]]"></gr-endpoint-param>
         <gr-endpoint-param name="change" value="[[change]]"></gr-endpoint-param>
         <gr-endpoint-param name="revision" value="[[revision]]"></gr-endpoint-param>
       </gr-endpoint-decorator>

polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata.js

@@ -42,6 +42,10 @@
     properties: {
       /** @type {?} */
       change: Object,
+      labels: {
+        type: Object,
+        notify: true,
+      },
       /** @type {?} */
       revision: Object,
       commitInfo: Object,
@@ -98,9 +102,14 @@
 
     observers: [
       '_changeChanged(change)',
+      '_labelsChanged(change.labels)',
       '_assigneeChanged(_assignee.*)',
     ],
 
+    _labelsChanged(labels) {
+      this.labels = Object.assign({}, labels) || null;
+    },
+
     _changeChanged(change) {
       this._assignee = change.assignee ? [change.assignee] : [];
     },
@@ -243,17 +252,22 @@
     },
 
     _computeTopicReadOnly(mutable, change) {
-      return !mutable || !change.actions.topic || !change.actions.topic.enabled;
+      return !mutable ||
+          !change.actions ||
+          !change.actions.topic ||
+          !change.actions.topic.enabled;
     },
 
     _computeHashtagReadOnly(mutable, change) {
       return !mutable ||
+          !change.actions ||
           !change.actions.hashtags ||
           !change.actions.hashtags.enabled;
     },
 
     _computeAssigneeReadOnly(mutable, change) {
       return !mutable ||
+          !change.actions ||
           !change.actions.assignee ||
           !change.actions.assignee.enabled;
     },
@@ -283,7 +297,9 @@
      *     change-metadata section is modifiable by the current user.
      */
     _computeCanDeleteVote(reviewer, mutable) {
-      if (!mutable) { return false; }
+      if (!mutable || !this.change || !this.change.removable_reviewers) {
+        return false;
+      }
       for (let i = 0; i < this.change.removable_reviewers.length; i++) {
         if (this.change.removable_reviewers[i]._account_id ===
             reviewer._account_id) {
@@ -313,6 +329,7 @@
             if (!response.ok) { return response; }
             const label = this.change.labels[labelName];
             const labels = label.all || [];
+            let wasChanged = false;
             for (let i = 0; i < labels.length; i++) {
               if (labels[i]._account_id === accountID) {
                 for (const key in label) {
@@ -320,13 +337,18 @@
                       label[key]._account_id === accountID) {
                     // Remove special label field, keeping change label values
                     // in sync with the backend.
-                    this.set(['change.labels', labelName, key], null);
+                    this.change.labels[labelName][key] = null;
+                    wasChanged = true;
                   }
                 }
-                this.splice(['change.labels', labelName, 'all'], i, 1);
+                this.change.labels[labelName].all.splice(i, 1);
+                wasChanged = true;
                 break;
               }
             }
+            if (wasChanged) {
+              this.notifyPath('change.labels');
+            }
           }).catch(err => {
             target.disabled = false;
             return;

polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_test.html

@@ -523,36 +523,26 @@ limitations under the License.
         assert.isFalse(button.hasAttribute('hidden'));
       });
 
-      test('deletes votes', done => {
-        const deleteStub = sandbox.stub(element.$.restAPI, 'deleteVote')
-            .returns(Promise.resolve({ok: true}));
+      test('deletes votes', () => {
+        const deleteResponse = Promise.resolve({ok: true});
+        const deleteStub = sandbox.stub(
+            element.$.restAPI, 'deleteVote').returns(deleteResponse);
 
-        element.change.removable_reviewers = [
-          {
-            _account_id: 1,
-            name: 'bojack',
-          },
-        ];
+        element.change.removable_reviewers = [{
+          _account_id: 1,
+          name: 'bojack',
+        }];
         element.change.labels.test.recommended = {_account_id: 1};
         element.mutable = true;
-        flushAsynchronousOperations();
         const chip = element.$$('gr-account-chip');
         const button = chip.$$('gr-button');
-
-        const spliceStub = sandbox.stub(element, 'splice', (path, index,
-            length) => {
-          assert.isFalse(chip.disabled);
-          assert.deepEqual(path, ['change.labels', 'test', 'all']);
-          assert.equal(index, 0);
-          assert.equal(length, 1);
-          assert.notOk(element.change.labels.test.recommended);
-          assert.isTrue(deleteStub.calledWithExactly(42, 1, 'test'));
-          spliceStub.restore();
-          done();
-        });
-
         MockInteractions.tap(button);
         assert.isTrue(chip.disabled);
+        return deleteResponse.then(() => {
+          assert.isFalse(chip.disabled);
+          assert.notOk(element.change.labels.test.recommended);
+          assert.isTrue(deleteStub.calledWithExactly(42, 1, 'test'));
+        });
       });
 
       test('changing topic', () => {

polygerrit-ui/app/elements/plugins/gr-change-metadata-api/gr-change-metadata-api.html

@@ -0,0 +1,22 @@
+<!--
+@license
+Copyright (C) 2018 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+<link rel="import" href="../../../bower_components/polymer/polymer.html">
+
+<dom-module id="gr-change-metadata-api">
+  <script src="gr-change-metadata-api.js"></script>
+</dom-module>

polygerrit-ui/app/elements/plugins/gr-change-metadata-api/gr-change-metadata-api.js

@@ -0,0 +1,39 @@
+/**
+ * @license
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+(function(window) {
+  'use strict';
+
+  function GrChangeMetadataApi(plugin) {
+    this._hook = null;
+    this.plugin = plugin;
+  }
+
+  GrChangeMetadataApi.prototype._createHook = function() {
+    this._hook = this.plugin.hook('change-metadata-item');
+  };
+
+  GrChangeMetadataApi.prototype.onLabelsChanged = function(callback) {
+    if (!this._hook) {
+      this._createHook();
+    }
+    this._hook.onAttached(element =>
+        this.plugin.attributeHelper(element).bind('labels', callback));
+    return this;
+  };
+
+  window.GrChangeMetadataApi = GrChangeMetadataApi;
+})(window);

polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-js-api-interface.html

@@ -20,6 +20,7 @@ limitations under the License.
 <link rel="import" href="../../core/gr-reporting/gr-reporting.html">
 <link rel="import" href="../../plugins/gr-admin-api/gr-admin-api.html">
 <link rel="import" href="../../plugins/gr-attribute-helper/gr-attribute-helper.html">
+<link rel="import" href="../../plugins/gr-change-metadata-api/gr-change-metadata-api.html">
 <link rel="import" href="../../plugins/gr-dom-hooks/gr-dom-hooks.html">
 <link rel="import" href="../../plugins/gr-event-helper/gr-event-helper.html">
 <link rel="import" href="../../plugins/gr-popup-interface/gr-popup-interface.html">

polygerrit-ui/app/elements/shared/gr-js-api-interface/gr-public-js-api.js

@@ -223,6 +223,10 @@
     return new GrRepoApi(this);
   };
 
+  Plugin.prototype.changeMetadata = function() {
+    return new GrChangeMetadataApi(this);
+  };
+
   Plugin.prototype.admin = function() {
     return new GrAdminApi(this);
   };