Adobe Experience Manager Assets developer use cases, APIs, and reference material

The article contains recommendations, reference materials, and resources for developers of Assets as a Cloud Service. It includes new asset upload module, API reference, and information about the support provided in post-processing workflows.

Experience Manager Assets APIs and operations

Assets as a Cloud Service provides several APIs to programmatically interact with digital assets. Each API supports specific use cases, as mentioned in the table below. The Assets user interface, Experience Manager desktop app and Adobe Asset Link support all or some of the operations.

CAUTION

Some APIs continue to exist but are not actively supported (denoted with an ×). To the extent possible, do not use these APIs.

Support level	Description
✓	Supported
×	Not supported. Do not use.
-	Not available

Use case	aem-upload	AEM / Sling / JCR Java APIs	Asset compute service	Assets HTTP API	Sling GET / POST servlets	GraphQL (Preview)
Original binary
Create original	✓	×	-	×	×	-
Read original	-	×	✓	✓	✓	-
Update original	✓	×	✓	×	×	-
Delete original	-	✓	-	✓	✓	-
Copy original	-	✓	-	✓	✓	-
Move original	-	✓	-	✓	✓	-
Metadata
Create metadata	-	✓	✓	✓	✓	-
Read metadata	-	✓	-	✓	✓	-
Update metadata	-	✓	✓	✓	✓	-
Delete metadata	-	✓	✓	✓	✓	-
Copy metadata	-	✓	-	✓	✓	-
Move metadata	-	✓	-	✓	✓	-
Content Fragments (CF)
Create CF	-	✓	-	✓	-	-
Read CF	-	✓	-	✓	-	✓
Update CF	-	✓	-	✓	-	-
Delete CF	-	✓	-	✓	-	-
Copy CF	-	✓	-	✓	-	-
Move CF	-	✓	-	✓	-	-
Versions
Create version	✓	✓	-	-	-	-
Read version	-	✓	-	-	-	-
Delete version	-	✓	-	-	-	-
Folders
Create folder	✓	✓	-	✓	-	-
Read folder	-	✓	-	✓	-	-
Delete folder	✓	✓	-	✓	-	-
Copy folder	✓	✓	-	✓	-	-
Move folder	✓	✓	-	✓	-	-

Asset upload

In Experience Manager as a Cloud Service, you can directly upload the assets to the cloud storage using HTTP API. The steps to upload a binary file are:

Submit an HTTP request. It informs Experience Manager deployment of your intent to upload a new binary.
POST the contents of the binary to one or more URIs provided by the initiation request.
Submit an HTTP request to inform the server that the contents of the binary were successfully uploaded.

Overview of direct binary upload protocol

The approach provides a scalable and more performant handling of asset uploads. The differences as compared to Experience Manager 6.5 are:

Binaries do not go through Experience Manager, which is now simply coordinating the upload process with the binary cloud storage configured for the deployment.
Binary cloud storage works with a Content Delivery Network (CDN) or Edge network. A CDN selects an upload endpoint that is nearer for a client. When data travels a shorter distance to a nearby endpoint, the upload performance and user experience improve, especially for geographically distributed teams.

NOTE

See the client code to implement this approach in the open-source aem-upload library.

Initiate upload

Submit an HTTP POST request to the desired folder. Assets are created or updated in this folder. Include the selector .initiateUpload.json to indicate that the request is to initiate upload of a binary file. For example, the path to the folder where the asset should be created is /assets/folder. The POST request is POST https://[aem_server]:[port]/content/dam/assets/folder.initiateUpload.json.

The content type of the request body should be application/x-www-form-urlencoded form data, containing the following fields:

(string) fileName: Required. The name of the asset as it appears in Experience Manager.
(number) fileSize: Required. The file size, in bytes, of the asset being uploaded.

A single request can be used to initiate uploads for multiple binaries, as long as each binary contains the required fields. If successful, the request responds with a 201 status code and a body containing JSON data in the following format:

{
    "completeURI": "(string)",
    "folderPath": (string)",
    "files": [
        {
            "fileName": "(string)",
            "mimeType": "(string)",
            "uploadToken": "(string)",
            "uploadURIs": [
                "(string)"
            ]
        }
    ]
}

completeURI (string): Call this URI when the binary finishes uploading. The URI can be an absolute or relative URI, and clients should be able to handle either. That is, the value can be "https://author.acme.com/content/dam.completeUpload.json" or "/content/dam.completeUpload.json" See complete upload.
folderPath (string): Full path to the folder in which the binary is uploaded.
(files) (array): A list of elements whose length and order match the length and order of the list of binary information provided in the initiate request.
fileName (string): The name of the corresponding binary, as supplied in the initiate request. This value should be included in the complete request.
mimeType (string): The mime type of the corresponding binary, as supplied in the initiate request. This value should be included in the complete request.
uploadToken (string): An upload token for the corresponding binary. This value should be included in the complete request.
uploadURIs (array): A list of strings whose values are full URIs to which the binary’s content should be uploaded (see Upload binary).
minPartSize (number): The minimum length, in bytes, of data that may be provided to any one of the uploadURIs, if there is more than one URI.
maxPartSize (number): The maximum length, in bytes, of data that may be provided to any one of the uploadURIs, if there is more than one URI.

Upload binary

The output of initiating an upload includes one or more upload URI values. If more than one URI is provided, the client splits the binary into parts and make POST request of each part to each URI, in order. Use all URIs. Ensure that the size of each part is within the minimum and maximum sizes as specified in the initiate response. CDN edge nodes help accelerate the requested upload of binaries.

A potential method to accomplish this is to calculate the part size based on the number of upload URIs provided by the API. For example, assume the total size of the binary is 20,000 bytes and the number of upload URIs is 2. Then follow these steps:

Calculate part size by dividing total size by number of URIs: 20,000 / 2 = 10,000.
POST byte range 0-9,999 of the binary to the first URI in the list of upload URIs.
POST byte range 10,000 - 19,999 of the binary to the second URI in the list of upload URIs.

If the upload is successful, the server responds to each request with a 201 status code.

Complete upload

After all the parts of a binary file are uploaded, submit an HTTP POST request to the complete URI provided by the initiation data. The content type of the request body should be application/x-www-form-urlencoded form data, containing the following fields.

Fields	Type	Required or not	Description
`fileName`	String	Required	The name of the asset, as was provided by the initiation data.
`mimeType`	String	Required	The HTTP content type of the binary, as was provided by the initiation data.
`uploadToken`	String	Required	Upload token for the binary, as was provided by the initiation data.
`createVersion`	Boolean	Optional	If `True` and an asset with the specified name exists, then Experience Manager creates a new version of the asset.
`versionLabel`	String	Optional	If a new version is created, the label associated with the new version of an asset .
`versionComment`	String	Optional	If a new version is created, the comments associated with the version.
`replace`	Boolean	Optional	If `True` and an asset with the specified name exists, Experience Manager deletes the asset then re-create it.

NOTE

If the asset exists and neither createVersion nor replace is specified, then Experience Manager updates the asset’s current version with the new binary.

Like the initiate process, the complete request data may contain information for more than one file.

The process of uploading a binary is not done until the complete URL is invoked for the file. An asset is processed after the upload process is complete. Processing does not start even if the asset’s binary file is uploaded completely but upload process is not completed.

If successful, the server responds with a 200 status code.

Open-source upload library

To learn more about the upload algorithms or to build your own upload scripts and tools, Adobe provides open-source libraries and tools:

Deprecated asset upload APIs

The new upload method is supported only for Adobe Experience Manager as a Cloud Service. The APIs from Adobe Experience Manager 6.5 are deprecated. The methods related to upload or update assets or renditions (any binary upload) are deprecated in the following APIs:

Experience Manager Assets HTTP API
AssetManager Java API, like AssetManager.createAsset(..)

Asset processing and post-processing workflows

In Experience Manager, the asset processing is based on Processing Profiles configuration that uses asset microservices. Processing does not require developer extensions.

For post-processing workflow configuration, use the standard workflows with extensions with custom steps.

Support of workflow steps in post-processing workflow

Customers upgrading from previous versions of Experience Manager can use asset microservices to process assets. The cloud-native asset microservices are much simpler to configure and use. A few workflow steps used in the DAM Update Asset workflow in the previous version are not supported.

Experience Manager as a Cloud Service support the following workflow steps:

com.day.cq.dam.similaritysearch.internal.workflow.process.AutoTagAssetProcess
com.day.cq.dam.core.impl.process.CreateAssetLanguageCopyProcess
com.day.cq.wcm.workflow.process.CreateVersionProcess
com.day.cq.dam.similaritysearch.internal.workflow.smarttags.StartTrainingProcess
com.day.cq.dam.similaritysearch.internal.workflow.smarttags.TransferTrainingDataProcess
com.day.cq.dam.core.impl.process.TranslateAssetLanguageCopyProcess
com.day.cq.dam.core.impl.process.UpdateAssetLanguageCopyProcess
com.adobe.cq.workflow.replication.impl.ReplicationWorkflowProcess
com.day.cq.dam.core.impl.process.DamUpdateAssetWorkflowCompletedProcess