Method initialize

src/service/url-replacements-impl.js:125–638

@override

()

  /** @override */
  initialize() {
    const {win} = this.ampdoc;
    const element = this.ampdoc.getHeadNode();

    /** @const {!./viewport/viewport-interface.ViewportInterface} */
    const viewport = Services.viewportForDoc(this.ampdoc);

    // Greedily cache the geo location if available for synchronous replacements.
    Services.geoForDocOrNull(this.ampdoc).then((geo) => {
      this.cachedGeo_ = geo;
    });

    // Returns a random value for cache busters.
    this.set('RANDOM', () => Math.random());

    // Provides a counter starting at 1 per given scope.
    const counterStore = Object.create(null);
    this.set('COUNTER', (scope) => {
      return (counterStore[scope] = (counterStore[scope] | 0) + 1);
    });

    // Returns the canonical URL for this AMP document.
    this.set('CANONICAL_URL', () => this.getDocInfo_().canonicalUrl);

    // Returns the host of the canonical URL for this AMP document.
    this.set(
      'CANONICAL_HOST',
      () => parseUrlDeprecated(this.getDocInfo_().canonicalUrl).host
    );

    // Returns the hostname of the canonical URL for this AMP document.
    this.set(
      'CANONICAL_HOSTNAME',
      () => parseUrlDeprecated(this.getDocInfo_().canonicalUrl).hostname
    );

    // Returns the path of the canonical URL for this AMP document.
    this.set(
      'CANONICAL_PATH',
      () => parseUrlDeprecated(this.getDocInfo_().canonicalUrl).pathname
    );

    // Returns the referrer URL.
    this.setAsync(
      'DOCUMENT_REFERRER',
      /** @type {AsyncResolverDef} */ (
        () => {
          return Services.viewerForDoc(this.ampdoc).getReferrerUrl();
        }
      )
    );

    // Like DOCUMENT_REFERRER, but returns null if the referrer is of
    // same domain or the corresponding CDN proxy.
    this.setAsync(
      'EXTERNAL_REFERRER',
      /** @type {AsyncResolverDef} */ (
        () => {