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- Created by Dominika Kurek, last modified by André Rømcke on Jan 04, 2017
Field Type identifier: ezimage
Validators: File size
Value object: \eZ\Publish\Core\FieldType\Image\Value
Associated Services: ezpublish.fieldType.ezimage.variation_service
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.
PHP API Field Type
Value object
The value property of an Image Field will return an \eZ\Publish\Core\FieldType\Image\Value object with the following properties:
Properties
| Property | Type | Example | Description |
|---|---|---|---|
id | string | 0/8/4/1/1480-1-eng-GB/image.png | The image's unique identifier. Usually the path, or a part of the path. To get the full path, use |
alternativeText | string | This is a piece of text | The alternative text, as entered in the Field's properties |
fileName | string | image.png | The original image's filename, without the path |
fileSize | int | 37931 | The original image's size, in bytes |
uri | string | var/ezdemo_site/storage/images/0/8/4/1/1480-1-eng-GB/image.png | The original image's URI |
imageId | string | 240-1480 | A special image ID, used by REST |
Image Variations
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:
| Property | Type | Example | Description |
|---|---|---|---|
width | int | 640 | The variation's width in pixels |
height | int | 480 | The variation's height in pixels |
name | string | medium | The variation's identifier |
info | mixed | Extra info, such as EXIF data | |
fileSize | int | ||
mimeType | string | ||
fileName | string | ||
dirPath | string | ||
uri | string | The variation's uri | |
lastModified | DateTime | When the variation was last modified |
Field Defintion options
The Image Field Type supports one FieldDefinition option: the maximum size for the file.
Using an Image Field
Template Rendering
When displayed using ez_render_field, an Image Field will output this type of HTML:
The template called by the ez_render_field() Twig function while rendering a Image field accepts the following the parameters:
| Parameter | Type | Default | Description |
|---|---|---|---|
alias | string | " | The image variation name, must be defined in your site access image_variations settings. Defaults to "original", the originally uploaded image. |
width | int | Optionally to specify a different width set on the image html tag then then one from image alias. | |
height | int | Optionally to specify a different height set on the image html tag then then one from image alias. | |
class | string | Optionally to specify a specific html class for use in custom javascript and/or css. |
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:
inputUri
From 5.2 version, new images must be input using the inputUri property from Image\Value.
The keys id and path still work, but a deprecation warning will be thrown.
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=1480VersionNumber=1LanguageCode=eng-GB
Images will be stored to web/var/ezdemo_site/storage/images/0/8/4/1/1480-1-eng-GB.
Using the field ID digits in reverse order as the folder structure maximizes sharding of files through multiple folders on the filesystem.
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