Image rendering 

EnrichFileDataEvent 

FileUtility is emitting the event EnrichFileDataEvent for manipulating the properties array.

To add a listener add this to your Configuration/Services.yaml:

My\Extension\EventListener\TweakFileData:
  tags:
    - name: event.listener
      identifier: 'tweak-file-data'
      event: FriendsOfTYPO3\Headless\Event\EnrichFileDataEvent

Configuration 

The rendering configuration can be set via the property processingConfiguration and provides the following sub-properties:

• legacyReturn (0|1): Allows to control new simplified output or old system (old system by default)
• linkResult (0|1): Allows to define if file object should return only url of defined link or whole LinkResult object
• cacheBusting (0|1): Allows to enable cacheBusting urls for processed files (enabled globally by the headless.assetsCacheBusting feature flag)
• width, height, minWidth, minHeight, maxWidth, maxHeight: image processing instructions passed to the core processor
• cropVariant (name): render a specific crop variant (default default)
• processGif (0|1): enable optional processing of gif files (default off)
• outputCropArea (0|1): include the resolved crop area in the output
• conditionalCropVariant (0|1): Allows conditionally autogenerate files with defined variants if set (if not all variants are returned)
• processPdfAsImage (0|1): Enabled optional processing pdf files as image (default off)
• processSvg (0|1): Enabled optional processing svg files (default off)
• properties.byType (0|1): Allows filter file properties by type (i.e. do not return video properties on images)
• properties.defaultFieldsByType (coma separated list of fields): Default fields for when enabled option properties.byType
• properties.defaultImageFields (coma separated list of fields): Default fields for image type when enabled option properties.byType
• properties.defaultVideoFields (coma separated list of fields): Default fields for video type when enabled option properties.byType
• properties.includeOnly (string, comma separated): Configure what file properties to return
• properties.flatten (0|1): Flatten nested properties (dimensions array) to use with properties.includeOnly
• returnFlattenObject: without that flag an array of (multiple) images is rendered. Set this if you're only rendering 1 image and want to reduce nesting.
• delayProcessing: can be used to skip processing of images (and have them simply collected with the FilesProcessor), in order to have them processed by the next processor in line (which is generally GalleryProcessor).
• fileExtension: can be used to convert the images to any desired format, e.g. webp.
• autogenerate: `retina2x`: set this to render an additional image URI in high quality (200%). lqip: set this to render an additional image URI with low quality (10%). * also custom defined size & file formats see example below

10 = FriendsOfTYPO3\Headless\DataProcessing\FilesProcessor
10 {
   ...
   processingConfiguration {
      delayProcessing = 1
   }
}
20 = FriendsOfTYPO3\Headless\DataProcessing\GalleryProcessor
20 {
   ...
   autogenerate {
      retina2x = 1
      customFileWebp {
         fileExtension = webp
         factor = 1.0
      }
      customTinyJpg {
         fileExtension = jpg
         factor = 0.2
      }
   }
}

10 = FriendsOfTYPO3\Headless\DataProcessing\FilesProcessor
10 {
   ...
   processingConfiguration {
      # (1 by default = legacy output; set 0 for the new simplified format)
      legacyReturn = 0
      # Return whole LinkResult object instead simple url
      linkResult = 1
      # check if we need to conditionally check if we should generate crop variants
      conditionalCropVariant = 1
      # Generate cacheBusting urls for images and video files
      cacheBusting = 1
      properties {
         # return props by mimeType
         byType = 1
         # return only properties defined below
         includeOnly = alternative,width,height
         # you can also alias fields
         # includeOnly = alternative as alt,width,height
         # with includeOnly you can use option `flatten` to flatten dimensions array
         flatten = 1
      }
   }
}

Configuration 

The rendering configuration is set directly on the processor: all options of the processingConfiguration block documented above (legacyReturn, fileExtension, cropVariant, …) are read from the processor's top-level configuration — there is no processingConfiguration. sub-key.

Default as is gallery. The processor also supports appendData (1 keeps the raw record data; absent or 0 — the default — strips data from the result) and cropVariant to select the crop variant used for the width/height calculation (default default).

• maxGalleryWidth: set to the core constant {$styles.content.textmedia.maxW}
• maxGalleryWidthInText: set to the core constant {$styles.content.textmedia.maxWInText}
• columnSpacing: set to the core constant {$styles.content.textmedia.columnSpacing}
• borderWidth: set to the core constant {$styles.content.textmedia.borderWidth}
• borderPadding: set to the core constant {$styles.content.textmedia.borderPadding}
• autogenerate `retina2x` lqip * custom keys with factor / fileExtension — same syntax as in the FilesProcessor example above