Image Field Type

The Image Field Type allows you to store an image file.

A variation service handles conversion of the original image into different formats and sizes through a set of preconfigured named variations: large, small, medium, black & white thumbnail, etc.

Value object

The value property of an Image Field will return an \eZ\Publish\Core\FieldType\Image\Value object with the following properties:

Using the variation Service, variations of the original image can be obtained. Those are \eZ\Publish\SPI\Variation\Values\ImageVariation objects with the following properties:

Field Type options

The Image Field Type supports one FieldDefinition option: the maximum size for the file.

Using an Image Field

In templates

When displayed using ez_render_field, an Image Field will output this type of HTML:

ez_render_field accepts several parameters:

• which variation must be used can be set using the alias parameter
• size and height can be forced for the image, for instance to handle custom screen densities. If not specified, the variation's attributes will be used if available.

Example: 

The raw Field can also be used if needed. Image variations for the Field's content can be obtained using the ez_image_alias Twig helper:

The variation's properties can be used to generate the required output:

With the REST API

Image Fields within REST are exposed by the application/vnd.ez.api.Content media-type. An Image Field will look like this:

Children of the fieldValue node will list the general properties of the Field's original image (fileSize, fileName, inputUri, etc.), as well as variations. For each variation, a uri is provided. Requested through REST, this resource will generate the variation if it doesn't exist yet, and list the variation details:

From PHP code

Getting an image variation

The variation service, ezpublish.fieldType.ezimage.variation_service, can be used to generate/get variations for a Field. It expects a VersionInfo, the Image Field and the variation name, as a string (large, medium, etc.)

Manipulating image content

From PHP

As for any Field Type, there are several ways to input content to a Field. For an Image, the quickest is to call setField() on the ContentStruct:

In order to customize the Image's alternative texts, you must first get an Image\Value object, and set this property. For that, you can use the Image\Value::fromString() method that accepts the path to a local file:

You can also provide a hash of Image\Value properties, either to setField(), or to the constructor:

From REST

The REST API expects Field values to be provided in a hash-like structure. Those keys are identical to those expected by the Image\Value constructor: fileName, alternativeText. In addition, image data can be provided using the data property, with the image's content encoded as base64.

Creating an image Field

Updating an image Field

Updating an Image Field requires that you re-send existing data. This can be done by re-using the Field obtained via REST, removing the variations key, and updating alternativeText, fileName or data. If you do not want to change the image itself, do not provide the data key.

Naming

Each storage engine determines how image files are named.

Legacy Storage Engine naming

Images are stored within the following directory structure:

<varDir>/<StorageDir>/<ImagesStorageDir>/<FieIdId[-1]>/<FieIdId[-2]>/<FieIdId[-3]>/<FieIdId[-4]>/<FieldId>-<VersionNumber>-<LanguageCode>/

With the following values:

• VarDir = var (default)
• StorageDir = storage (default)
• ImagesStorageDir = images (default)
• FieldId = 1480
• VersionNumber = 1
• LanguageCode = eng-GB

Images will be stored to web/var/ezdemo_site/storage/images/0/8/4/1/1480-1-eng-GB.

Within this folder, images will be named like the uploaded file, suffixed with an underscore and the variation name:

• MyImage.png
• MyImage_large.png
• MyImage_rss.png