WEBDEV-6386 Refactor facets to extract individual facet row component (#297)

* Simplify facet event model

* Create new component for individual facet row

* Clean up now-unused code in facets-template

* Update tests to reflect new DOM structure

* Fix facet analytics events

* Update remaining tests

* Add add'l tests for facet template events

* DRY up a duplicate method + one more unit test

* Minor simplification of facet event detail obj

* Improve readability for facet row CSS vars

Author: latonv

src/collection-browser.ts

@@ -1751,27 +1751,26 @@ export class CollectionBrowser
   }
 
   facetClickHandler({
-    detail: { key, state: facetState, negative },
+    detail: { facetType, bucket, negative },
   }: CustomEvent<FacetEventDetails>): void {
+    let action: analyticsActions;
     if (negative) {
-      this.analyticsHandler?.sendEvent({
-        category: this.searchContext,
-        action:
-          facetState !== 'none'
-            ? analyticsActions.facetNegativeSelected
-            : analyticsActions.facetNegativeDeselected,
-        label: key,
-      });
+      action =
+        bucket.state !== 'none'
+          ? analyticsActions.facetNegativeSelected
+          : analyticsActions.facetNegativeDeselected;
     } else {
-      this.analyticsHandler?.sendEvent({
-        category: this.searchContext,
-        action:
-          facetState !== 'none'
-            ? analyticsActions.facetSelected
-            : analyticsActions.facetDeselected,
-        label: key,
-      });
+      action =
+        bucket.state !== 'none'
+          ? analyticsActions.facetSelected
+          : analyticsActions.facetDeselected;
     }
+
+    this.analyticsHandler?.sendEvent({
+      category: this.searchContext,
+      action,
+      label: facetType,
+    });
   }
 
   private async fetchFacets() {

src/collection-facets/facet-row.ts

@@ -0,0 +1,274 @@
+import {
+  css,
+  html,
+  LitElement,
+  TemplateResult,
+  CSSResultGroup,
+  nothing,
+} from 'lit';
+import { customElement, property } from 'lit/decorators.js';
+import type { CollectionNameCacheInterface } from '@internetarchive/collection-name-cache';
+import eyeIcon from '../assets/img/icons/eye';
+import eyeClosedIcon from '../assets/img/icons/eye-closed';
+import type {
+  FacetOption,
+  FacetBucket,
+  FacetEventDetails,
+  FacetState,
+} from '../models';
+
+@customElement('facet-row')
+export class FacetRow extends LitElement {
+  //
+  // UI STATE
+  //
+
+  /** The name of the facet group to which this facet belongs (e.g., "mediatype") */
+  @property({ type: String }) facetType?: FacetOption;
+
+  /** The facet bucket containing details about the state, count, and key for this row */
+  @property({ type: Object }) bucket?: FacetBucket;
+
+  /** The collection name cache for converting collection identifiers to titles */
+  @property({ type: Object })
+  collectionNameCache?: CollectionNameCacheInterface;
+
+  //
+  // COMPONENT LIFECYCLE METHODS
+  //
+
+  render() {
+    return html`${this.facetRowTemplate}`;
+  }
+
+  //
+  // TEMPLATE GETTERS
+  //
+
+  /**
+   * Template for the full facet row, including the positive/negative checks,
+   * the display name, and the count.
+   */
+  private get facetRowTemplate(): TemplateResult | typeof nothing {
+    const { bucket, facetType } = this;
+    if (!bucket || !facetType) return nothing;
+
+    const showOnlyCheckboxId = `${facetType}:${bucket.key}-show-only`;
+    const negativeCheckboxId = `${facetType}:${bucket.key}-negative`;
+
+    // For collections, we need to asynchronously load the collection name
+    // so we use the `async-collection-name` widget.
+    // For other facet types, we just have a static value to use.
+    const bucketTextDisplay =
+      facetType !== 'collection'
+        ? html`${bucket.displayText ?? bucket.key}`
+        : html`<a href="/details/${bucket.key}">
+            <async-collection-name
+              .collectionNameCache=${this.collectionNameCache}
+              .identifier=${bucket.key}
+              placeholder="-"
+            ></async-collection-name>
+          </a> `;
+
+    const facetHidden = bucket.state === 'hidden';
+    const facetSelected = bucket.state === 'selected';
+
+    const titleText = `${facetType}: ${bucket.displayText ?? bucket.key}`;
+    const onlyShowText = facetSelected
+      ? `Show all ${facetType}s`
+      : `Only show ${titleText}`;
+    const hideText = `Hide ${titleText}`;
+    const unhideText = `Unhide ${titleText}`;
+    const showHideText = facetHidden ? unhideText : hideText;
+    const ariaLabel = `${titleText}, ${bucket.count} results`;
+
+    return html`
+      <div class="facet-row-container">
+        <div class="facet-checkboxes">
+          <input
+            type="checkbox"
+            .name=${facetType}
+            .value=${bucket.key}
+            @click=${(e: Event) => {
+              this.facetClicked(e, false);
+            }}
+            .checked=${facetSelected}
+            class="select-facet-checkbox"
+            title=${onlyShowText}
+            id=${showOnlyCheckboxId}
+          />
+          <input
+            type="checkbox"
+            id=${negativeCheckboxId}
+            .name=${facetType}
+            .value=${bucket.key}
+            @click=${(e: Event) => {
+              this.facetClicked(e, true);
+            }}
+            .checked=${facetHidden}
+            class="hide-facet-checkbox"
+          />
+          <label
+            for=${negativeCheckboxId}
+            class="hide-facet-icon${facetHidden ? ' active' : ''}"
+            title=${showHideText}
+          >
+            <span class="eye">${eyeIcon}</span>
+            <span class="eye-closed">${eyeClosedIcon}</span>
+          </label>
+        </div>
+        <label
+          for=${showOnlyCheckboxId}
+          class="facet-info-display"
+          title=${onlyShowText}
+          aria-label=${ariaLabel}
+        >
+          <div class="facet-title">${bucketTextDisplay}</div>
+          <div class="facet-count">${bucket.count.toLocaleString()}</div>
+        </label>
+      </div>
+    `;
+  }
+
+  //
+  // EVENT HANDLERS & DISPATCHERS
+  //
+
+  /**
+   * Handler for whenever this facet is clicked & its state changes
+   */
+  private facetClicked(e: Event, negative: boolean) {
+    const { bucket, facetType } = this;
+    if (!bucket || !facetType) return;
+
+    const target = e.target as HTMLInputElement;
+    const { checked } = target;
+    bucket.state = FacetRow.getFacetState(checked, negative);
+
+    this.dispatchFacetClickEvent({
+      facetType,
+      bucket,
+      negative,
+    });
+  }
+
+  /**
+   * Emits a `facetClick` event with details about this facet & its current state
+   */
+  private dispatchFacetClickEvent(detail: FacetEventDetails) {
+    const event = new CustomEvent<FacetEventDetails>('facetClick', {
+      detail,
+    });
+    this.dispatchEvent(event);
+  }
+
+  //
+  // OTHER METHODS
+  //
+
+  /**
+   * Returns the composed facet state corresponding to a positive or negative facet's checked state
+   */
+  static getFacetState(checked: boolean, negative: boolean): FacetState {
+    let state: FacetState;
+    if (checked) {
+      state = negative ? 'hidden' : 'selected';
+    } else {
+      state = 'none';
+    }
+    return state;
+  }
+
+  //
+  // STYLES
+  //
+
+  static get styles(): CSSResultGroup {
+    const facetRowBorderTop = css`var(--facet-row-border-top, 1px solid transparent)`;
+    const facetRowBorderBottom = css`var(--facet-row-border-bottom, 1px solid transparent)`;
+
+    return css`
+      async-collection-name {
+        display: contents;
+      }
+      .facet-checkboxes {
+        margin: 0 5px 0 0;
+        display: flex;
+        height: 15px;
+      }
+      .facet-checkboxes input:first-child {
+        margin-right: 5px;
+      }
+      .facet-checkboxes input {
+        height: 15px;
+        width: 15px;
+        margin: 0;
+      }
+      .facet-row-container {
+        display: flex;
+        font-weight: 500;
+        font-size: 1.2rem;
+        margin: 2.5px auto;
+        height: auto;
+        border-top: ${facetRowBorderTop};
+        border-bottom: ${facetRowBorderBottom};
+        overflow: hidden;
+      }
+      .facet-info-display {
+        display: flex;
+        flex: 1 1 0%;
+        cursor: pointer;
+        flex-wrap: wrap;
+      }
+      .facet-title {
+        word-break: break-word;
+        display: inline-block;
+        flex: 1 1 0%;
+      }
+      .facet-count {
+        text-align: right;
+      }
+      .select-facet-checkbox {
+        cursor: pointer;
+        display: inline-block;
+      }
+      .hide-facet-checkbox {
+        display: none;
+      }
+      .hide-facet-icon {
+        width: 15px;
+        height: 15px;
+        cursor: pointer;
+        opacity: 0.3;
+        display: inline-block;
+      }
+      .hide-facet-icon:hover,
+      .active {
+        opacity: 1;
+      }
+      .hide-facet-icon:hover .eye,
+      .hide-facet-icon .eye-closed {
+        display: none;
+      }
+      .hide-facet-icon:hover .eye-closed,
+      .hide-facet-icon.active .eye-closed {
+        display: inline;
+      }
+      .hide-facet-icon.active .eye {
+        display: none;
+      }
+      .sorting-icon {
+        cursor: pointer;
+      }
+
+      a:link,
+      a:visited {
+        text-decoration: none;
+        color: var(--ia-theme-link-color, #4b64ff);
+      }
+      a:hover {
+        text-decoration: underline;
+      }
+    `;
+  }
+}