Merge branch '332262-introduce-a-feature-flag-for-labels-refactoring' into 'master'

Introduce a feature flag for labels widget [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!62898

app/assets/javascripts/sidebar/components/labels/sidebar_labels.vue

@@ -10,6 +10,8 @@ import updateMergeRequestLabelsMutation from '~/sidebar/queries/update_merge_req
 import { toLabelGid } from '~/sidebar/utils';
 import { DropdownVariant } from '~/vue_shared/components/sidebar/labels_select_vue/constants';
 import LabelsSelect from '~/vue_shared/components/sidebar/labels_select_vue/labels_select_root.vue';
+import LabelsSelectWidget from '~/vue_shared/components/sidebar/labels_select_widget/labels_select_root.vue';
+import glFeatureFlagMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 
 const mutationMap = {
   [IssuableType.Issue]: {
@@ -25,8 +27,10 @@ const mutationMap = {
 export default {
   components: {
     LabelsSelect,
+    LabelsSelectWidget,
   },
   variant: DropdownVariant.Sidebar,
+  mixins: [glFeatureFlagMixin()],
   inject: [
     'allowLabelCreate',
     'allowLabelEdit',
@@ -135,7 +139,32 @@ export default {
 </script>
 
 <template>
+  <labels-select-widget
+    v-if="glFeatures.labelsWidget"
+    class="block labels js-labels-block"
+    :allow-label-remove="allowLabelEdit"
+    :allow-label-create="allowLabelCreate"
+    :allow-label-edit="allowLabelEdit"
+    :allow-multiselect="true"
+    :allow-scoped-labels="allowScopedLabels"
+    :footer-create-label-title="__('Create project label')"
+    :footer-manage-label-title="__('Manage project labels')"
+    :labels-create-title="__('Create project label')"
+    :labels-fetch-path="labelsFetchPath"
+    :labels-filter-base-path="projectIssuesPath"
+    :labels-manage-path="labelsManagePath"
+    :labels-select-in-progress="isLabelsSelectInProgress"
+    :selected-labels="selectedLabels"
+    :variant="$options.sidebar"
+    data-qa-selector="labels_block"
+    @onDropdownClose="handleDropdownClose"
+    @onLabelRemove="handleLabelRemove"
+    @updateSelectedLabels="handleUpdateSelectedLabels"
+  >
+    {{ __('None') }}
+  </labels-select-widget>
   <labels-select
+    v-else
     class="block labels js-labels-block"
     :allow-label-remove="allowLabelEdit"
     :allow-label-create="allowLabelCreate"

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/constants.js

+export const DropdownVariant = {
+  Sidebar: 'sidebar',
+  Standalone: 'standalone',
+  Embedded: 'embedded',
+};

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/dropdown_button.vue

+<script>
+import { GlButton, GlIcon } from '@gitlab/ui';
+import { mapActions, mapGetters } from 'vuex';
+
+export default {
+  components: {
+    GlButton,
+    GlIcon,
+  },
+  computed: {
+    ...mapGetters([
+      'dropdownButtonText',
+      'isDropdownVariantStandalone',
+      'isDropdownVariantEmbedded',
+    ]),
+  },
+  methods: {
+    ...mapActions(['toggleDropdownContents']),
+    handleButtonClick(e) {
+      if (this.isDropdownVariantStandalone || this.isDropdownVariantEmbedded) {
+        this.toggleDropdownContents();
+      }
+
+      if (this.isDropdownVariantStandalone) {
+        e.stopPropagation();
+      }
+    },
+  },
+};
+</script>
+
+<template>
+  <gl-button
+    class="labels-select-dropdown-button js-dropdown-button w-100 text-left"
+    @click="handleButtonClick"
+  >
+    <span class="dropdown-toggle-text gl-pointer-events-none flex-fill">
+      {{ dropdownButtonText }}
+    </span>
+    <gl-icon name="chevron-down" class="gl-pointer-events-none float-right" />
+  </gl-button>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/dropdown_contents.vue

+<script>
+import { mapGetters, mapState } from 'vuex';
+
+import DropdownContentsCreateView from './dropdown_contents_create_view.vue';
+import DropdownContentsLabelsView from './dropdown_contents_labels_view.vue';
+
+export default {
+  components: {
+    DropdownContentsLabelsView,
+    DropdownContentsCreateView,
+  },
+  props: {
+    renderOnTop: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  computed: {
+    ...mapState(['showDropdownContentsCreateView']),
+    ...mapGetters(['isDropdownVariantSidebar']),
+    dropdownContentsView() {
+      if (this.showDropdownContentsCreateView) {
+        return 'dropdown-contents-create-view';
+      }
+      return 'dropdown-contents-labels-view';
+    },
+    directionStyle() {
+      const bottom = this.isDropdownVariantSidebar ? '3rem' : '2rem';
+      return this.renderOnTop ? { bottom } : {};
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    class="labels-select-dropdown-contents gl-w-full gl-my-2 gl-py-3 gl-rounded-base gl-absolute"
+    data-qa-selector="labels_dropdown_content"
+    :style="directionStyle"
+  >
+    <component :is="dropdownContentsView" />
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/dropdown_contents_create_view.vue

+<script>
+import { GlTooltipDirective, GlButton, GlFormInput, GlLink, GlLoadingIcon } from '@gitlab/ui';
+import { mapState, mapActions } from 'vuex';
+
+export default {
+  components: {
+    GlButton,
+    GlFormInput,
+    GlLink,
+    GlLoadingIcon,
+  },
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
+  data() {
+    return {
+      labelTitle: '',
+      selectedColor: '',
+    };
+  },
+  computed: {
+    ...mapState(['labelsCreateTitle', 'labelCreateInProgress']),
+    disableCreate() {
+      return !this.labelTitle.length || !this.selectedColor.length || this.labelCreateInProgress;
+    },
+    suggestedColors() {
+      const colorsMap = gon.suggested_label_colors;
+      return Object.keys(colorsMap).map((color) => ({ [color]: colorsMap[color] }));
+    },
+  },
+  methods: {
+    ...mapActions(['toggleDropdownContents', 'toggleDropdownContentsCreateView', 'createLabel']),
+    getColorCode(color) {
+      return Object.keys(color).pop();
+    },
+    getColorName(color) {
+      return Object.values(color).pop();
+    },
+    handleColorClick(color) {
+      this.selectedColor = this.getColorCode(color);
+    },
+    handleCreateClick() {
+      this.createLabel({
+        title: this.labelTitle,
+        color: this.selectedColor,
+      });
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="labels-select-contents-create js-labels-create">
+    <div class="dropdown-title d-flex align-items-center pt-0 pb-2">
+      <gl-button
+        :aria-label="__('Go back')"
+        variant="link"
+        size="small"
+        class="js-btn-back dropdown-header-button p-0"
+        icon="arrow-left"
+        @click="toggleDropdownContentsCreateView"
+      />
+      <span class="flex-grow-1">{{ labelsCreateTitle }}</span>
+      <gl-button
+        :aria-label="__('Close')"
+        variant="link"
+        size="small"
+        class="dropdown-header-button p-0"
+        icon="close"
+        @click="toggleDropdownContents"
+      />
+    </div>
+    <div class="dropdown-input">
+      <gl-form-input
+        v-model.trim="labelTitle"
+        :placeholder="__('Name new label')"
+        :autofocus="true"
+      />
+    </div>
+    <div class="dropdown-content px-2">
+      <div class="suggest-colors suggest-colors-dropdown mt-0 mb-2">
+        <gl-link
+          v-for="(color, index) in suggestedColors"
+          :key="index"
+          v-gl-tooltip:tooltipcontainer
+          :style="{ backgroundColor: getColorCode(color) }"
+          :title="getColorName(color)"
+          @click.prevent="handleColorClick(color)"
+        />
+      </div>
+      <div class="color-input-container gl-display-flex">
+        <span
+          class="dropdown-label-color-preview position-relative position-relative d-inline-block"
+          :style="{ backgroundColor: selectedColor }"
+        ></span>
+        <gl-form-input
+          v-model.trim="selectedColor"
+          class="gl-rounded-top-left-none gl-rounded-bottom-left-none"
+          :placeholder="__('Use custom color #FF0000')"
+        />
+      </div>
+    </div>
+    <div class="dropdown-actions clearfix pt-2 px-2">
+      <gl-button
+        :disabled="disableCreate"
+        category="primary"
+        variant="success"
+        class="float-left d-flex align-items-center"
+        @click="handleCreateClick"
+      >
+        <gl-loading-icon v-show="labelCreateInProgress" :inline="true" class="mr-1" />
+        {{ __('Create') }}
+      </gl-button>
+      <gl-button class="float-right js-btn-cancel-create" @click="toggleDropdownContentsCreateView">
+        {{ __('Cancel') }}
+      </gl-button>
+    </div>
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/dropdown_contents_labels_view.vue

+<script>
+import {
+  GlIntersectionObserver,
+  GlLoadingIcon,
+  GlButton,
+  GlSearchBoxByType,
+  GlLink,
+} from '@gitlab/ui';
+import fuzzaldrinPlus from 'fuzzaldrin-plus';
+import { mapState, mapGetters, mapActions } from 'vuex';
+
+import { UP_KEY_CODE, DOWN_KEY_CODE, ENTER_KEY_CODE, ESC_KEY_CODE } from '~/lib/utils/keycodes';
+
+import LabelItem from './label_item.vue';
+
+export default {
+  components: {
+    GlIntersectionObserver,
+    GlLoadingIcon,
+    GlButton,
+    GlSearchBoxByType,
+    GlLink,
+    LabelItem,
+  },
+  data() {
+    return {
+      searchKey: '',
+      currentHighlightItem: -1,
+    };
+  },
+  computed: {
+    ...mapState([
+      'allowLabelCreate',
+      'allowMultiselect',
+      'labelsManagePath',
+      'labels',
+      'labelsFetchInProgress',
+      'labelsListTitle',
+      'footerCreateLabelTitle',
+      'footerManageLabelTitle',
+    ]),
+    ...mapGetters(['selectedLabelsList', 'isDropdownVariantSidebar', 'isDropdownVariantEmbedded']),
+    visibleLabels() {
+      if (this.searchKey) {
+        return fuzzaldrinPlus.filter(this.labels, this.searchKey, {
+          key: ['title'],
+        });
+      }
+      return this.labels;
+    },
+    showNoMatchingResultsMessage() {
+      return Boolean(this.searchKey) && this.visibleLabels.length === 0;
+    },
+  },
+  watch: {
+    searchKey(value) {
+      // When there is search string present
+      // and there are matching results,
+      // highlight first item by default.
+      if (value && this.visibleLabels.length) {
+        this.currentHighlightItem = 0;
+      }
+    },
+  },
+  methods: {
+    ...mapActions([
+      'toggleDropdownContents',
+      'toggleDropdownContentsCreateView',
+      'fetchLabels',
+      'receiveLabelsSuccess',
+      'updateSelectedLabels',
+      'toggleDropdownContents',
+    ]),
+    isLabelSelected(label) {
+      return this.selectedLabelsList.includes(label.id);
+    },
+    /**
+     * This method scrolls item from dropdown into
+     * the view if it is off the viewable area of the
+     * container.
+     */
+    scrollIntoViewIfNeeded() {
+      const highlightedLabel = this.$refs.labelsListContainer.querySelector('.is-focused');
+
+      if (highlightedLabel) {
+        const container = this.$refs.labelsListContainer.getBoundingClientRect();
+        const label = highlightedLabel.getBoundingClientRect();
+
+        if (label.bottom > container.bottom) {
+          this.$refs.labelsListContainer.scrollTop += label.bottom - container.bottom;
+        } else if (label.top < container.top) {
+          this.$refs.labelsListContainer.scrollTop -= container.top - label.top;
+        }
+      }
+    },
+    handleComponentAppear() {
+      // We can avoid putting `catch` block here
+      // as failure is handled within actions.js already.
+      return this.fetchLabels().then(() => {
+        this.$refs.searchInput.focusInput();
+      });
+    },
+    /**
+     * We want to remove loaded labels to ensure component
+     * fetches fresh set of labels every time when shown.
+     */
+    handleComponentDisappear() {
+      this.receiveLabelsSuccess([]);
+    },
+    handleCreateLabelClick() {
+      this.receiveLabelsSuccess([]);
+      this.toggleDropdownContentsCreateView();
+    },
+    /**
+     * This method enables keyboard navigation support for
+     * the dropdown.
+     */
+    handleKeyDown(e) {
+      if (e.keyCode === UP_KEY_CODE && this.currentHighlightItem > 0) {
+        this.currentHighlightItem -= 1;
+      } else if (
+        e.keyCode === DOWN_KEY_CODE &&
+        this.currentHighlightItem < this.visibleLabels.length - 1
+      ) {
+        this.currentHighlightItem += 1;
+      } else if (e.keyCode === ENTER_KEY_CODE && this.currentHighlightItem > -1) {
+        this.updateSelectedLabels([this.visibleLabels[this.currentHighlightItem]]);
+        this.searchKey = '';
+      } else if (e.keyCode === ESC_KEY_CODE) {
+        this.toggleDropdownContents();
+      }
+
+      if (e.keyCode !== ESC_KEY_CODE) {
+        // Scroll the list only after highlighting
+        // styles are rendered completely.
+        this.$nextTick(() => {
+          this.scrollIntoViewIfNeeded();
+        });
+      }
+    },
+    handleLabelClick(label) {
+      this.updateSelectedLabels([label]);
+      if (!this.allowMultiselect) this.toggleDropdownContents();
+    },
+  },
+};
+</script>
+
+<template>
+  <gl-intersection-observer @appear="handleComponentAppear" @disappear="handleComponentDisappear">
+    <div class="labels-select-contents-list js-labels-list" @keydown="handleKeyDown">
+      <div
+        v-if="isDropdownVariantSidebar || isDropdownVariantEmbedded"
+        class="dropdown-title gl-display-flex gl-align-items-center gl-pt-0 gl-pb-3!"
+        data-testid="dropdown-title"
+      >
+        <span class="flex-grow-1">{{ labelsListTitle }}</span>
+        <gl-button
+          :aria-label="__('Close')"
+          variant="link"
+          size="small"
+          class="dropdown-header-button gl-p-0!"
+          icon="close"
+          @click="toggleDropdownContents"
+        />
+      </div>
+      <div class="dropdown-input" @click.stop="() => {}">
+        <gl-search-box-by-type
+          ref="searchInput"
+          v-model="searchKey"
+          :disabled="labelsFetchInProgress"
+          data-qa-selector="dropdown_input_field"
+        />
+      </div>
+      <div ref="labelsListContainer" class="dropdown-content" data-testid="dropdown-content">
+        <gl-loading-icon
+          v-if="labelsFetchInProgress"
+          class="labels-fetch-loading gl-align-items-center w-100 h-100"
+          size="md"
+        />
+        <ul v-else class="list-unstyled gl-mb-0 gl-word-break-word">
+          <label-item
+            v-for="(label, index) in visibleLabels"
+            :key="label.id"
+            :label="label"
+            :is-label-set="label.set"
+            :highlight="index === currentHighlightItem"
+            @clickLabel="handleLabelClick(label)"
+          />
+          <li v-show="showNoMatchingResultsMessage" class="gl-p-3 gl-text-center">
+            {{ __('No matching results') }}
+          </li>
+        </ul>
+      </div>
+      <div
+        v-if="isDropdownVariantSidebar || isDropdownVariantEmbedded"
+        class="dropdown-footer"
+        data-testid="dropdown-footer"
+      >
+        <ul class="list-unstyled">
+          <li v-if="allowLabelCreate">
+            <gl-link
+              class="gl-display-flex w-100 flex-row text-break-word label-item"
+              @click="handleCreateLabelClick"
+            >
+              {{ footerCreateLabelTitle }}
+            </gl-link>
+          </li>
+          <li>
+            <gl-link
+              :href="labelsManagePath"
+              class="gl-display-flex flex-row text-break-word label-item"
+            >
+              {{ footerManageLabelTitle }}
+            </gl-link>
+          </li>
+        </ul>
+      </div>
+    </div>
+  </gl-intersection-observer>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/dropdown_title.vue

+<script>
+import { GlButton, GlLoadingIcon } from '@gitlab/ui';
+import { mapState, mapActions } from 'vuex';
+
+export default {
+  components: {
+    GlButton,
+    GlLoadingIcon,
+  },
+  props: {
+    labelsSelectInProgress: {
+      type: Boolean,
+      required: true,
+    },
+  },
+  computed: {
+    ...mapState(['allowLabelEdit', 'labelsFetchInProgress']),
+  },
+  methods: {
+    ...mapActions(['toggleDropdownContents']),
+  },
+};
+</script>
+
+<template>
+  <div class="title hide-collapsed gl-mb-3">
+    {{ __('Labels') }}
+    <template v-if="allowLabelEdit">
+      <gl-loading-icon v-show="labelsSelectInProgress" inline />
+      <gl-button
+        variant="link"
+        class="float-right js-sidebar-dropdown-toggle"
+        data-qa-selector="labels_edit_button"
+        @click="toggleDropdownContents"
+        >{{ __('Edit') }}</gl-button
+      >
+    </template>
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/dropdown_value.vue

+<script>
+import { GlLabel } from '@gitlab/ui';
+import { mapState } from 'vuex';
+
+import { isScopedLabel } from '~/lib/utils/common_utils';
+
+export default {
+  components: {
+    GlLabel,
+  },
+  props: {
+    disableLabels: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  computed: {
+    ...mapState([
+      'selectedLabels',
+      'allowLabelRemove',
+      'allowScopedLabels',
+      'labelsFilterBasePath',
+      'labelsFilterParam',
+    ]),
+  },
+  methods: {
+    labelFilterUrl(label) {
+      return `${this.labelsFilterBasePath}?${this.labelsFilterParam}[]=${encodeURIComponent(
+        label.title,
+      )}`;
+    },
+    scopedLabel(label) {
+      return this.allowScopedLabels && isScopedLabel(label);
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    :class="{
+      'has-labels': selectedLabels.length,
+    }"
+    class="hide-collapsed value issuable-show-labels js-value"
+  >
+    <span v-if="!selectedLabels.length" class="text-secondary">
+      <slot></slot>
+    </span>
+    <template v-for="label in selectedLabels" v-else>
+      <gl-label
+        :key="label.id"
+        data-qa-selector="selected_label_content"
+        :data-qa-label-name="label.title"
+        :title="label.title"
+        :description="label.description"
+        :background-color="label.color"
+        :target="labelFilterUrl(label)"
+        :scoped="scopedLabel(label)"
+        :show-close-button="allowLabelRemove"
+        :disabled="disableLabels"
+        tooltip-placement="top"
+        @close="$emit('onLabelRemove', label.id)"
+      />
+    </template>
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/label_item.vue

+<script>
+import { GlLink, GlIcon } from '@gitlab/ui';
+
+export default {
+  functional: true,
+  props: {
+    label: {
+      type: Object,
+      required: true,
+    },
+    isLabelSet: {
+      type: Boolean,
+      required: true,
+    },
+    highlight: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  render(h, { props, listeners }) {
+    const { label, highlight, isLabelSet } = props;
+
+    const labelColorBox = h('span', {
+      class: 'dropdown-label-box gl-flex-shrink-0 gl-top-0 gl-mr-3',
+      style: {
+        backgroundColor: label.color,
+      },
+      attrs: {
+        'data-testid': 'label-color-box',
+      },
+    });
+
+    const checkedIcon = h(GlIcon, {
+      class: {
+        'gl-mr-3 gl-flex-shrink-0': true,
+        hidden: !isLabelSet,
+      },
+      props: {
+        name: 'mobile-issue-close',
+      },
+    });
+
+    const noIcon = h('span', {
+      class: {
+        'gl-mr-5 gl-pr-3': true,
+        hidden: isLabelSet,
+      },
+      attrs: {
+        'data-testid': 'no-icon',
+      },
+    });
+
+    const labelTitle = h('span', label.title);
+
+    const labelLink = h(
+      GlLink,
+      {
+        class: 'gl-display-flex gl-align-items-center label-item gl-text-black-normal',
+        on: {
+          click: () => {
+            listeners.clickLabel(label);
+          },
+        },
+      },
+      [noIcon, checkedIcon, labelColorBox, labelTitle],
+    );
+
+    return h(
+      'li',
+      {
+        class: {
+          'gl-display-block': true,
+          'gl-text-left': true,
+          'is-focused': highlight,
+        },
+      },
+      [labelLink],
+    );
+  },
+};
+</script>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/labels_select_root.vue

+<script>
+import $ from 'jquery';
+import Vue from 'vue';
+import Vuex, { mapState, mapActions, mapGetters } from 'vuex';
+import { isInViewport } from '~/lib/utils/common_utils';
+import { __ } from '~/locale';
+
+import DropdownValueCollapsed from '~/vue_shared/components/sidebar/labels_select/dropdown_value_collapsed.vue';
+
+import { DropdownVariant } from './constants';
+import DropdownButton from './dropdown_button.vue';
+import DropdownContents from './dropdown_contents.vue';
+import DropdownTitle from './dropdown_title.vue';
+import DropdownValue from './dropdown_value.vue';
+import labelsSelectModule from './store';
+
+Vue.use(Vuex);
+
+export default {
+  store: new Vuex.Store(labelsSelectModule()),
+  components: {
+    DropdownTitle,
+    DropdownValue,
+    DropdownButton,
+    DropdownContents,
+    DropdownValueCollapsed,
+  },
+  props: {
+    allowLabelRemove: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    allowLabelEdit: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    allowLabelCreate: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    allowMultiselect: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    allowScopedLabels: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    variant: {
+      type: String,
+      required: false,
+      default: DropdownVariant.Sidebar,
+    },
+    selectedLabels: {
+      type: Array,
+      required: false,
+      default: () => [],
+    },
+    labelsSelectInProgress: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    labelsFetchPath: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    labelsManagePath: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    labelsFilterBasePath: {
+      type: String,
+      required: false,
+      default: '',
+    },
+    labelsFilterParam: {
+      type: String,
+      required: false,
+      default: 'label_name',
+    },
+    dropdownButtonText: {
+      type: String,
+      required: false,
+      default: __('Label'),
+    },
+    labelsListTitle: {
+      type: String,
+      required: false,
+      default: __('Assign labels'),
+    },
+    labelsCreateTitle: {
+      type: String,
+      required: false,
+      default: __('Create group label'),
+    },
+    footerCreateLabelTitle: {
+      type: String,
+      required: false,
+      default: __('Create group label'),
+    },
+    footerManageLabelTitle: {
+      type: String,
+      required: false,
+      default: __('Manage group labels'),
+    },
+    isEditing: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  data() {
+    return {
+      contentIsOnViewport: true,
+    };
+  },
+  computed: {
+    ...mapState(['showDropdownButton', 'showDropdownContents']),
+    ...mapGetters([
+      'isDropdownVariantSidebar',
+      'isDropdownVariantStandalone',
+      'isDropdownVariantEmbedded',
+    ]),
+    dropdownButtonVisible() {
+      return this.isDropdownVariantSidebar ? this.showDropdownButton : true;
+    },
+  },
+  watch: {
+    selectedLabels(selectedLabels) {
+      this.setInitialState({
+        selectedLabels,
+      });
+    },
+    showDropdownContents(showDropdownContents) {
+      this.setContentIsOnViewport(showDropdownContents);
+    },
+    isEditing(newVal) {
+      if (newVal) {
+        this.toggleDropdownContents();
+      }
+    },
+  },
+  mounted() {
+    this.setInitialState({
+      variant: this.variant,
+      allowLabelRemove: this.allowLabelRemove,
+      allowLabelEdit: this.allowLabelEdit,
+      allowLabelCreate: this.allowLabelCreate,
+      allowMultiselect: this.allowMultiselect,
+      allowScopedLabels: this.allowScopedLabels,
+      dropdownButtonText: this.dropdownButtonText,
+      selectedLabels: this.selectedLabels,
+      labelsFetchPath: this.labelsFetchPath,
+      labelsManagePath: this.labelsManagePath,
+      labelsFilterBasePath: this.labelsFilterBasePath,
+      labelsFilterParam: this.labelsFilterParam,
+      labelsListTitle: this.labelsListTitle,
+      labelsCreateTitle: this.labelsCreateTitle,
+      footerCreateLabelTitle: this.footerCreateLabelTitle,
+      footerManageLabelTitle: this.footerManageLabelTitle,
+    });
+
+    this.$store.subscribeAction({
+      after: this.handleVuexActionDispatch,
+    });
+
+    document.addEventListener('mousedown', this.handleDocumentMousedown);
+    document.addEventListener('click', this.handleDocumentClick);
+  },
+  beforeDestroy() {
+    document.removeEventListener('mousedown', this.handleDocumentMousedown);
+    document.removeEventListener('click', this.handleDocumentClick);
+  },
+  methods: {
+    ...mapActions(['setInitialState', 'toggleDropdownContents']),
+    /**
+     * This method differentiates between
+     * dispatched actions and calls necessary method.
+     */
+    handleVuexActionDispatch(action, state) {
+      if (
+        action.type === 'toggleDropdownContents' &&
+        !state.showDropdownButton &&
+        !state.showDropdownContents
+      ) {
+        let filterFn = (label) => label.touched;
+        if (this.isDropdownVariantEmbedded) {
+          filterFn = (label) => label.set;
+        }
+        this.handleDropdownClose(state.labels.filter(filterFn));
+      }
+    },
+    /**
+     * This method stores a mousedown event's target.
+     * Required by the click listener because the click
+     * event itself has no reference to this element.
+     */
+    handleDocumentMousedown({ target }) {
+      this.mousedownTarget = target;
+    },
+    /**
+     * This method listens for document-wide click event
+     * and toggle dropdown if user clicks anywhere outside
+     * the dropdown while dropdown is visible.
+     */
+    handleDocumentClick({ target }) {
+      // We also perform the toggle exception check for the
+      // last mousedown event's target to avoid hiding the
+      // box when the mousedown happened inside the box and
+      // only the mouseup did not.
+      if (
+        this.showDropdownContents &&
+        !this.preventDropdownToggleOnClick(target) &&
+        !this.preventDropdownToggleOnClick(this.mousedownTarget)
+      ) {
+        this.toggleDropdownContents();
+      }
+    },
+    /**
+     * This method checks whether a given click target
+     * should prevent the dropdown from being toggled.
+     */
+    preventDropdownToggleOnClick(target) {
+      // This approach of element detection is needed
+      // as the dropdown wrapper is not using `GlDropdown` as
+      // it will also require us to use `BDropdownForm`
+      // which is yet to be implemented in GitLab UI.
+      const hasExceptionClass = [
+        'js-dropdown-button',
+        'js-btn-cancel-create',
+        'js-sidebar-dropdown-toggle',
+      ].some(
+        (className) =>
+          target?.classList.contains(className) ||
+          target?.parentElement?.classList.contains(className),
+      );
+
+      const hasExceptionParent = ['.js-btn-back', '.js-labels-list'].some(
+        (className) => $(target).parents(className).length,
+      );
+
+      const isInDropdownButtonCollapsed = this.$refs.dropdownButtonCollapsed?.$el.contains(target);
+
+      const isInDropdownContents = this.$refs.dropdownContents?.$el.contains(target);
+
+      return (
+        hasExceptionClass ||
+        hasExceptionParent ||
+        isInDropdownButtonCollapsed ||
+        isInDropdownContents
+      );
+    },
+    handleDropdownClose(labels) {
+      // Only emit label updates if there are any labels to update
+      // on UI.
+      if (labels.length) this.$emit('updateSelectedLabels', labels);
+      this.$emit('onDropdownClose');
+    },
+    handleCollapsedValueClick() {
+      this.$emit('toggleCollapse');
+    },
+    setContentIsOnViewport(showDropdownContents) {
+      if (!showDropdownContents) {
+        this.contentIsOnViewport = true;
+
+        return;
+      }
+
+      this.$nextTick(() => {
+        if (this.$refs.dropdownContents) {
+          this.contentIsOnViewport = isInViewport(this.$refs.dropdownContents.$el);
+        }
+      });
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    class="labels-select-wrapper position-relative"
+    :class="{
+      'is-standalone': isDropdownVariantStandalone,
+      'is-embedded': isDropdownVariantEmbedded,
+    }"
+  >
+    <template v-if="isDropdownVariantSidebar">
+      <dropdown-value-collapsed
+        ref="dropdownButtonCollapsed"
+        :labels="selectedLabels"
+        @onValueClick="handleCollapsedValueClick"
+      />
+      <dropdown-title
+        :allow-label-edit="allowLabelEdit"
+        :labels-select-in-progress="labelsSelectInProgress"
+      />
+      <dropdown-value
+        :disable-labels="labelsSelectInProgress"
+        @onLabelRemove="$emit('onLabelRemove', $event)"
+      >
+        <slot></slot>
+      </dropdown-value>
+      <dropdown-button v-show="dropdownButtonVisible" class="gl-mt-2" />
+      <dropdown-contents
+        v-show="dropdownButtonVisible && showDropdownContents"
+        ref="dropdownContents"
+        :render-on-top="!contentIsOnViewport"
+      />
+    </template>
+    <template v-if="isDropdownVariantStandalone || isDropdownVariantEmbedded">
+      <dropdown-button v-show="dropdownButtonVisible" />
+      <dropdown-contents
+        v-if="dropdownButtonVisible && showDropdownContents"
+        ref="dropdownContents"
+        :render-on-top="!contentIsOnViewport"
+      />
+    </template>
+  </div>
+</template>

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/store/actions.js

+import { deprecatedCreateFlash as flash } from '~/flash';
+import axios from '~/lib/utils/axios_utils';
+import { __ } from '~/locale';
+import * as types from './mutation_types';
+
+export const setInitialState = ({ commit }, props) => commit(types.SET_INITIAL_STATE, props);
+
+export const toggleDropdownButton = ({ commit }) => commit(types.TOGGLE_DROPDOWN_BUTTON);
+export const toggleDropdownContents = ({ commit }) => commit(types.TOGGLE_DROPDOWN_CONTENTS);
+
+export const toggleDropdownContentsCreateView = ({ commit }) =>
+  commit(types.TOGGLE_DROPDOWN_CONTENTS_CREATE_VIEW);
+
+export const requestLabels = ({ commit }) => commit(types.REQUEST_LABELS);
+export const receiveLabelsSuccess = ({ commit }, labels) =>
+  commit(types.RECEIVE_SET_LABELS_SUCCESS, labels);
+export const receiveLabelsFailure = ({ commit }) => {
+  commit(types.RECEIVE_SET_LABELS_FAILURE);
+  flash(__('Error fetching labels.'));
+};
+export const fetchLabels = ({ state, dispatch }) => {
+  dispatch('requestLabels');
+  return axios
+    .get(state.labelsFetchPath)
+    .then(({ data }) => {
+      dispatch('receiveLabelsSuccess', data);
+    })
+    .catch(() => dispatch('receiveLabelsFailure'));
+};
+
+export const requestCreateLabel = ({ commit }) => commit(types.REQUEST_CREATE_LABEL);
+export const receiveCreateLabelSuccess = ({ commit }) => commit(types.RECEIVE_CREATE_LABEL_SUCCESS);
+export const receiveCreateLabelFailure = ({ commit }) => {
+  commit(types.RECEIVE_CREATE_LABEL_FAILURE);
+  flash(__('Error creating label.'));
+};
+export const createLabel = ({ state, dispatch }, label) => {
+  dispatch('requestCreateLabel');
+  axios
+    .post(state.labelsManagePath, {
+      label,
+    })
+    .then(({ data }) => {
+      if (data.id) {
+        dispatch('receiveCreateLabelSuccess');
+        dispatch('toggleDropdownContentsCreateView');
+      } else {
+        // eslint-disable-next-line @gitlab/require-i18n-strings
+        throw new Error('Error Creating Label');
+      }
+    })
+    .catch(() => {
+      dispatch('receiveCreateLabelFailure');
+    });
+};
+
+export const updateSelectedLabels = ({ commit }, labels) =>
+  commit(types.UPDATE_SELECTED_LABELS, { labels });

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/store/getters.js

+import { __, s__, sprintf } from '~/locale';
+import { DropdownVariant } from '../constants';
+
+/**
+ * Returns string representing current labels
+ * selection on dropdown button.
+ *
+ * @param {object} state
+ */
+export const dropdownButtonText = (state, getters) => {
+  const selectedLabels = getters.isDropdownVariantSidebar
+    ? state.labels.filter((label) => label.set)
+    : state.selectedLabels;
+
+  if (!selectedLabels.length) {
+    return state.dropdownButtonText || __('Label');
+  } else if (selectedLabels.length > 1) {
+    return sprintf(s__('LabelSelect|%{firstLabelName} +%{remainingLabelCount} more'), {
+      firstLabelName: selectedLabels[0].title,
+      remainingLabelCount: selectedLabels.length - 1,
+    });
+  }
+  return selectedLabels[0].title;
+};
+
+/**
+ * Returns array containing only label IDs from
+ * selectedLabels array.
+ * @param {object} state
+ */
+export const selectedLabelsList = (state) => state.selectedLabels.map((label) => label.id);
+
+/**
+ * Returns boolean representing whether dropdown variant
+ * is `sidebar`
+ * @param {object} state
+ */
+export const isDropdownVariantSidebar = (state) => state.variant === DropdownVariant.Sidebar;
+
+/**
+ * Returns boolean representing whether dropdown variant
+ * is `standalone`
+ * @param {object} state
+ */
+export const isDropdownVariantStandalone = (state) => state.variant === DropdownVariant.Standalone;
+
+/**
+ * Returns boolean representing whether dropdown variant
+ * is `embedded`
+ * @param {object} state
+ */
+export const isDropdownVariantEmbedded = (state) => state.variant === DropdownVariant.Embedded;

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/store/index.js

+import * as actions from './actions';
+import * as getters from './getters';
+import mutations from './mutations';
+import state from './state';
+
+export default () => ({
+  namespaced: true,
+  state: state(),
+  actions,
+  getters,
+  mutations,
+});

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/store/mutation_types.js

+export const SET_INITIAL_STATE = 'SET_INITIAL_STATE';
+
+export const REQUEST_LABELS = 'REQUEST_LABELS';
+export const RECEIVE_LABELS_SUCCESS = 'RECEIVE_LABELS_SUCCESS';
+export const RECEIVE_LABELS_FAILURE = 'RECEIVE_LABELS_FAILURE';
+
+export const REQUEST_SET_LABELS = 'REQUEST_SET_LABELS';
+export const RECEIVE_SET_LABELS_SUCCESS = 'RECEIVE_SET_LABELS_SUCCESS';
+export const RECEIVE_SET_LABELS_FAILURE = 'RECEIVE_SET_LABELS_FAILURE';
+
+export const REQUEST_CREATE_LABEL = 'REQUEST_CREATE_LABEL';
+export const RECEIVE_CREATE_LABEL_SUCCESS = 'RECEIVE_CREATE_LABEL_SUCCESS';
+export const RECEIVE_CREATE_LABEL_FAILURE = 'RECEIVE_CREATE_LABEL_FAILURE';
+
+export const TOGGLE_DROPDOWN_BUTTON = 'TOGGLE_DROPDOWN_VISIBILITY';
+export const TOGGLE_DROPDOWN_CONTENTS = 'TOGGLE_DROPDOWN_CONTENTS';
+
+export const UPDATE_SELECTED_LABELS = 'UPDATE_SELECTED_LABELS';
+
+export const TOGGLE_DROPDOWN_CONTENTS_CREATE_VIEW = 'TOGGLE_DROPDOWN_CONTENTS_CREATE_VIEW';

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/store/mutations.js

+import { DropdownVariant } from '../constants';
+import * as types from './mutation_types';
+
+export default {
+  [types.SET_INITIAL_STATE](state, props) {
+    Object.assign(state, { ...props });
+  },
+
+  [types.TOGGLE_DROPDOWN_BUTTON](state) {
+    state.showDropdownButton = !state.showDropdownButton;
+  },
+
+  [types.TOGGLE_DROPDOWN_CONTENTS](state) {
+    if (state.variant === DropdownVariant.Sidebar) {
+      state.showDropdownButton = !state.showDropdownButton;
+    }
+    state.showDropdownContents = !state.showDropdownContents;
+    // Ensure that Create View is hidden by default
+    // when dropdown contents are revealed.
+    if (state.showDropdownContents) {
+      state.showDropdownContentsCreateView = false;
+    }
+  },
+
+  [types.TOGGLE_DROPDOWN_CONTENTS_CREATE_VIEW](state) {
+    state.showDropdownContentsCreateView = !state.showDropdownContentsCreateView;
+  },
+
+  [types.REQUEST_LABELS](state) {
+    state.labelsFetchInProgress = true;
+  },
+  [types.RECEIVE_SET_LABELS_SUCCESS](state, labels) {
+    // Iterate over every label and add a `set` prop
+    // to determine whether it is already a part of
+    // selectedLabels array.
+    const selectedLabelIds = state.selectedLabels.map((label) => label.id);
+    state.labelsFetchInProgress = false;
+    state.labels = labels.reduce((allLabels, label) => {
+      allLabels.push({
+        ...label,
+        set: selectedLabelIds.includes(label.id),
+      });
+      return allLabels;
+    }, []);
+  },
+  [types.RECEIVE_SET_LABELS_FAILURE](state) {
+    state.labelsFetchInProgress = false;
+  },
+
+  [types.REQUEST_CREATE_LABEL](state) {
+    state.labelCreateInProgress = true;
+  },
+  [types.RECEIVE_CREATE_LABEL_SUCCESS](state) {
+    state.labelCreateInProgress = false;
+  },
+  [types.RECEIVE_CREATE_LABEL_FAILURE](state) {
+    state.labelCreateInProgress = false;
+  },
+
+  [types.UPDATE_SELECTED_LABELS](state, { labels }) {
+    // Find the label to update from all the labels
+    // and change `set` prop value to represent their current state.
+    const labelId = labels.pop()?.id;
+    const candidateLabel = state.labels.find((label) => labelId === label.id);
+    if (candidateLabel) {
+      candidateLabel.touched = true;
+      candidateLabel.set = !candidateLabel.set;
+    }
+  },
+};

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/store/state.js

+export default () => ({
+  // Initial Data
+  labels: [],
+  selectedLabels: [],
+  labelsListTitle: '',
+  labelsCreateTitle: '',
+  footerCreateLabelTitle: '',
+  footerManageLabelTitle: '',
+  dropdownButtonText: '',
+
+  // Paths
+  namespace: '',
+  labelsFetchPath: '',
+  labelsFilterBasePath: '',
+
+  // UI Flags
+  variant: '',
+  allowLabelRemove: false,
+  allowLabelCreate: false,
+  allowLabelEdit: false,
+  allowScopedLabels: false,
+  allowMultiselect: false,
+  showDropdownButton: false,
+  showDropdownContents: false,
+  showDropdownContentsCreateView: false,
+  labelsFetchInProgress: false,
+  labelCreateInProgress: false,
+  selectedLabelsUpdated: false,
+});

app/controllers/projects/issues_controller.rb

@@ -55,6 +55,7 @@ class Projects::IssuesController < Projects::ApplicationController
     push_to_gon_attributes(:features, real_time_feature_flag, real_time_enabled)
     push_frontend_feature_flag(:confidential_notes, @project, default_enabled: :yaml)
     push_frontend_feature_flag(:issue_assignees_widget, @project, default_enabled: :yaml)
+    push_frontend_feature_flag(:labels_widget, @project, default_enabled: :yaml)
 
     experiment(:invite_members_in_comment, namespace: @project.root_ancestor) do |experiment_instance|
       experiment_instance.exclude! unless helpers.can_import_members?

config/feature_flags/development/labels_widget.yml

+---
+name: labels_widget
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/62898
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/332327
+milestone: '14.0'
+type: development
+group: group::project management
+default_enabled: false