Class CardHeader

The header of a Card.

Available for Google Workspace Add-ons and Google Chat apps.

const cardHeader = CardService.newCardHeader()
                       .setTitle('Card header title')
                       .setSubtitle('Card header subtitle')
                       .setImageStyle(CardService.ImageStyle.CIRCLE)
                       .setImageUrl('https://image.png');

Methods

Method	Return type	Brief description
`setImageAltText(imageAltText)`	`CardHeader`	Sets the alternative text for the header image.
`setImageStyle(imageStyle)`	`CardHeader`	Sets the cropping of the icon in the card header.
`setImageUrl(imageUrl)`	`CardHeader`	Sets the image to use in the header by providing its URL or data string.
`setSubtitle(subtitle)`	`CardHeader`	Sets the subtitle of the card header.
`setTitle(title)`	`CardHeader`	Sets the title of the card header.

Detailed documentation

`setImageAltText(imageAltText)`

Sets the alternative text for the header image.

Parameters

Name	Type	Description
`imageAltText`	`String`	The alternative text for the header image.

Return

CardHeader — This object, for chaining.

`setImageStyle(imageStyle)`

Sets the cropping of the icon in the card header. Defaults to no crop. Optional.

Parameters

Name	Type	Description
`imageStyle`	`ImageStyle`	The style setting.

Return

CardHeader — This object, for chaining.

`setImageUrl(imageUrl)`

Sets the image to use in the header by providing its URL or data string.

The provided URL can either be a publicly accessible URL or a base64 encoded image string. To obtain the latter, you can use the following code to create an encoded image string from an image in your Google Drive, then store that string for later use with setImageUrl(imageUrl). This method prevents the need for your add-on to access a publicly available image URL:

// The following assumes you have the image to use in Google Drive and have its
// ID.
const imageBytes = DriveApp.getFileById(imageID).getBlob().getBytes();
const encodedImageURL =
    `data:image/jpeg;base64,${Utilities.base64Encode(imageBytes)}`;

// You can store encodeImageURL and use it as a parameter to
// CardHeader.setImageUrl(imageUrl).

Parameters

Name	Type	Description
`imageUrl`	`String`	The URL address of a hosted image to use, or an encoded image string.

Return

CardHeader — This object, for chaining.

`setSubtitle(subtitle)`

Sets the subtitle of the card header. Optional.

Parameters

Name	Type	Description
`subtitle`	`String`	The header subtitle text.

Return

CardHeader — This object, for chaining.

`setTitle(title)`

Sets the title of the card header. Required.

Parameters

Name	Type	Description
`title`	`String`	The header text.

Return

CardHeader — This object, for chaining.