使用 Compose 操作扩展 Compose 界面

/**
 * Compose trigger function that fires when the compose UI is
 * requested. Builds and returns a compose UI for inserting images.
 *
 * @param {event} e The compose trigger event object. Not used in
 *         this example.
 * @return {Card[]}
 */
function getComposeUI(e) {
  return [buildComposeCard()];
}

/**
 * Build a card to display interactive buttons to allow the user to
 * update the subject, and To, Cc, Bcc recipients.
 *
 * @return {Card}
 */
function buildComposeCard() {

  var card = CardService.newCardBuilder();
  var cardSection = CardService.newCardSection().setHeader('Update email');
  cardSection.addWidget(
      CardService.newTextButton()
          .setText('Update subject')
          .setOnClickAction(CardService.newAction()
              .setFunctionName('applyUpdateSubjectAction')));
  cardSection.addWidget(
      CardService.newTextButton()
          .setText('Update To recipients')
          .setOnClickAction(CardService.newAction()
              .setFunctionName('updateToRecipients')));
  cardSection.addWidget(
      CardService.newTextButton()
          .setText('Update Cc recipients')
          .setOnClickAction(CardService.newAction()
              .setFunctionName('updateCcRecipients')));
  cardSection.addWidget(
      CardService.newTextButton()
          .setText('Update Bcc recipients')
          .setOnClickAction(CardService.newAction()
              .setFunctionName('updateBccRecipients')));
  return card.addSection(cardSection).build();
}

/**
 * Updates the subject field of the current email when the user clicks
 * on "Update subject" in the compose UI.
 *
 * Note: This is not the compose action that builds a compose UI, but
 * rather an action taken when the user interacts with the compose UI.
 *
 * @return {UpdateDraftActionResponse}
 */
function applyUpdateSubjectAction() {
  // Get the new subject field of the email.
  // This function is not shown in this example.
  var subject = getSubject();
  var response = CardService.newUpdateDraftActionResponseBuilder()
      .setUpdateDraftSubjectAction(CardService.newUpdateDraftSubjectAction()
          .addUpdateSubject(subject))
      .build();
  return response;
}

/**
 * Updates the To recipients of the current email when the user clicks
 * on "Update To recipients" in the compose UI.
 *
 * Note: This is not the compose action that builds a compose UI, but
 * rather an action taken when the user interacts with the compose UI.
 *
 * @return {UpdateDraftActionResponse}
 */
function applyUpdateToRecipientsAction() {
  // Get the new To recipients of the email.
  // This function is not shown in this example.
  var toRecipients = getToRecipients();
  var response = CardService.newUpdateDraftActionResponseBuilder()
      .setUpdateDraftToRecipientsAction(CardService.newUpdateDraftToRecipientsAction()
          .addUpdateToRecipients(toRecipients))
      .build();
  return response;
}

/**
 * Updates the Cc recipients  of the current email when the user clicks
 * on "Update Cc recipients" in the compose UI.
 *
 * Note: This is not the compose action that builds a compose UI, but
 * rather an action taken when the user interacts with the compose UI.
 *
 * @return {UpdateDraftActionResponse}
 */
function applyUpdateCcRecipientsAction() {
  // Get the new Cc recipients of the email.
  // This function is not shown in this example.
  var ccRecipients = getCcRecipients();
  var response = CardService.newUpdateDraftActionResponseBuilder()
      .setUpdateDraftCcRecipientsAction(CardService.newUpdateDraftCcRecipientsAction()
          .addUpdateToRecipients(ccRecipients))
      .build();
  return response;
}

/**
 * Updates the Bcc recipients  of the current email when the user clicks
 * on "Update Bcc recipients" in the compose UI.
 *
 * Note: This is not the compose action that builds a compose UI, but
 * rather an action taken when the user interacts with the compose UI.
 *
 * @return {UpdateDraftActionResponse}
 */
function applyUpdateBccRecipientsAction() {
  // Get the new Bcc recipients of the email.
  // This function is not shown in this example.
  var bccRecipients = getBccRecipients();
  var response = CardService.newUpdateDraftActionResponseBuilder()
      .setUpdateDraftBccRecipientsAction(CardService.newUpdateDraftBccRecipientsAction()
          .addUpdateToRecipients(bccRecipients))
      .build();
  return response;
}

/**
 * Compose trigger function that fires when the compose UI is
 * requested. Builds and returns a compose UI for inserting images.
 *
 * @param {event} e The compose trigger event object. Not used in
 *         this example.
 * @return {Card[]}
 */
function getInsertImageComposeUI(e) {
  return [buildImageComposeCard()];
}

/**
 * Build a card to display images from a third-party source.
 *
 * @return {Card}
 */
function buildImageComposeCard() {
  // Get a short list of image URLs to display in the UI.
  // This function is not shown in this example.
  var imageUrls = getImageUrls();

  var card = CardService.newCardBuilder();
  var cardSection = CardService.newCardSection().setHeader('My Images');
  for (var i = 0; i < imageUrls.length; i++) {
    var imageUrl = imageUrls[i];
    cardSection.addWidget(
        CardService.newImage()
            .setImageUrl(imageUrl)
            .setOnClickAction(CardService.newAction()
                  .setFunctionName('applyInsertImageAction')
                  .setParameters({'url' : imageUrl})));
  }
  return card.addSection(cardSection).build();
}

/**
 * Adds an image to the current draft email when the image is clicked
 * in the compose UI. The image is inserted at the current cursor
 * location. If any content of the email draft is currently selected,
 * it is deleted and replaced with the image.
 *
 * Note: This is not the compose action that builds a compose UI, but
 * rather an action taken when the user interacts with the compose UI.
 *
 * @param {event} e The incoming event object.
 * @return {UpdateDraftActionResponse}
 */
function applyInsertImageAction(e) {
  var imageUrl = e.parameters.url;
  var imageHtmlContent = '<img style=\"display: block\" src=\"'
        + imageUrl + '\"/>';
  var response = CardService.newUpdateDraftActionResponseBuilder()
      .setUpdateDraftBodyAction(CardService.newUpdateDraftBodyAction()
          .addUpdateContent(
              imageHtmlContent,
              CardService.ContentType.MUTABLE_HTML)
          .setUpdateType(
              CardService.UpdateDraftBodyType.IN_PLACE_INSERT))
      .build();
  return response;
}