Method observeIntersection

3p/ampcontext.js:175–183

* Send message to runtime to start sending intersection messages. * @param {function(Array )} callback Function to call every time we * receive an intersection message. * @return {function()} that when called stops triggering the callback * every time we receive an inters

(callback)

   *    every time we receive an intersection message.
   */
  observeIntersection(callback) {
    return this.client_.makeRequest(
      MessageType_Enum.SEND_INTERSECTIONS,
      MessageType_Enum.INTERSECTION,
      (intersection) => {
        callback(intersection['changes']);
      }
    );
  }

  /**
   *  Requests HTML snippet from the parent window.