If you use a Magnolia bundle, the required and optional modules are already included.
If you created a custom webapp, add the following modules in the pom file of the webapp of your bundle. The modules may have dependencies to other modules but these dependencies are handled by Maven dependency management.
Modules required for basic image operations.
Modules required when using a Rendition of an asset, such as size variations of an image. Recommended.
Selecting the image in dialog with a link field
To select an image in a dialog use the Link field, it stores a reference to the selected asset.
Example - code fragment from a dialog definition
Displaying an image
To render an image, you need to get a link to the asset. Use the link as a value in the
src attribute of the
Getting an image link with an itemKey
#getAssetLink(itemKey) method if you have the itemKey of the image. See: Get link for asset. For instance, the textImage component stores the itemKey in the
image property. This is a very common use case.
Example: Getting an image link with an itemKey. Assume that this code is executed in a component template. The current
content node has a property named
image where the itemKey is stored.
Getting an image link for an asset
#getLink() method if you already have the asset. Since an Asset object is a Java bean you can use its public method
#getLink(). You may even use the dot notation.
Example: Getting an image link for an asset
Displaying resized images
Defining image variations
Configure your image variations in a theme. Each variation should be a node under
<my-theme>/imaging/variations. The variation node name such as
small-square is what you will be referencing in your template scripts. It is also known as rendition name.
Example: Defining three image variations in a theme.
Image variations for the various renditions of an image on the page.
VariationAwareImagingSupport provides support for variations.
Enables and disables variation support.
Map of image variations.
The name of the variation, a.k.a the rendition name. Choose a name that describes the variation. The name is used in template scripts to reference the variation. Add one node for every variation.
You can use one of the available classes or create a custom one. The available properties depend on the class used for the variation. Any custom class must implement Variation.
Magnolia Templating Essentials module provides:
|Add properties that are supported by the class used.|
On the node
/modules/site/config/themes/<your-theme>/imaging you must specify the class property. The used class must implement ImagingSupport. MTE module provides VariationAwareImagingSupport which is a good choice for our use case here.
Add one node for every required variations below
<your-theme>/imaging/variations. The name of such a node is the name of the variation. also known as the rendition name. In the example above we have defined the renditions
For every variation you have to configure some properties. The available properties depend on the class you use in the variation. You can implement your own class. The definition class must implement the Variation interface.
In the example above we use SimpleResizeVariation. This class is provided by the
magnolia-templating-essentials-imaging module. Your webapp bundle must contain the module.
Class must implement SimpleResizeVariation.
An integer to define the height in pixels. You must configure either height or width or both.
An integer to define the width in pixels. You must configure either height or width or both.
optional , default is
Defines whether cropping the image is allowed to fit the desired aspect ratio.
Example: A source image in the DAM is 800x800 px (square). In a variation you define the desired target size as 200x100 (rectangle) so the aspect ratio changes. By default
*) You must define either width or height. If you do not define either, the renderer internally throws an ImagingException but displays the default size, the size of the original uploaded image. When you define both width and height, the image is resized accordingly and is cropped if the ratio does not fit. If you define only width or only height, the other property is calculated accordingly based on the ratio of the original image.
Make sure the site where you want to display the image variations references the theme. In the Site app, the theme
name property must be the same as the main node of the configured theme, in this example
Getting an image variation
Example: Getting an image variation (asset rendition) with an itemKey. Assume that
content in this example stores the itemKey in the
Example: Getting an image variation (asset rendition) for an asset.
Image variation cache
Magnolia caches image resources to improve performance. Any dynamic images generated by the Imaging module are also cached at two levels: in the
imaging workspace and in the actual cache like any other page or document. This means that once the system generates an image, you keep getting the same cached image on subsequent requests.
Disable image cache during development
During developing it is helpful to disable caching of generated images completely. Go to Configuration >
/server/filters/servlets/ImagingServlet/parameters, create a new property
storeGeneratedImages, and set its value to
Remove the property or to set it to
true after having finished image variation development. Do not use this property in your production environment!
Deleting imaging variations in the imaging workspace
Once image variations are stored in the
imaging workspaces, they remain there. After you remove the
storeGeneratedImages property, any cached image variations are served from the
imaging workspace again. Delete the nodes from the workspace.
Option 1: Groovy script. In the script,
examples-theme is the name of your theme. You can run this script in the Groovy console or add a new script and run it.
Option 2: Delete the nodes in the
imaging workspace in JCR Browser app.