Out of the box pipeline transformer definitions - Out of the box pipeline transformer definitions - Alfresco - Alfresco Transform Service - Alfresco/Alfresco-Transform-Service/4.1/Alfresco-Transform-Service/Configure/Add-T-Engines-to-T-Router/Out-of-the-box-pipeline-transformer-definitions - 4.1 - 4.1

The T-Router supports pipeline transformers, allowing it to perform transformations in a sequence of requests to various engines. This functionality is identical in definition to Content Services pipeline transformers (starting from Alfresco Transform Service 1.3.0). For more information on these pipelines, see the Content Services GitHub documentation on Configuring a custom transform pipeline as the T-Router pipeline transformers are defined using the same format. Due to this commonality, pipelines defined in Content Services can be moved to Transform Service directly. However, it’s worth mentioning that most of the pipeline definitions provided out of the box are identical to the pipeline definitions in Content Services.

The pipeline configuration file provided is bundled in the standard T-Router artifact/Docker image (the top resource being transformer-pipelines.json).

The default file is specified through the SpringBoot property transformer-routes-path, which can be overridden by the TRANSFORMER_ROUTES_PATH environment variable.

Here’s one of the pipeline transformers that provides additional transforms defined in the provided transformer-pipelines.json file:

{
    "transformers": [
        {
            "transformerName": "pdfToImageViaPng",
            "transformerPipeline": [
                {
                    "transformerName": "pdfrenderer",
                    "targetMediaType": "image/png"
                },
                {
                    "transformerName": "imagemagick"
                }
            ],
            "supportedSourceAndTargetList": [],
            "transformOptions": [
                "pdfRendererOptions",
                "imageMagickOptions"
            ]
        }
    ]
}

The above definition will introduce a new transformer, specifically a pipeline transformer called pdfToImageViaPng. The pipeline transformer is made up of two single-step transformers, pdfrenderer and imagemagick. If the supportedSourceAndTargetList is left blank, then the T-Router will complete the supported list automatically. The supported list can be restricted to specific sources and targets by explicitly defining them, just like a single-step transformer in an engine would. Priorities can be used to override conflicting transforms provided by other transformers.