Content Services GraphQL Development

The section describes the Content Services GraphQL API feature set that simplifies application development for your Content Platform Engine.

Overview
The Content Services GraphQL API provides a schema and an easy-to-understand query language system that simplifies application development for your Content Platform Engine.
GraphQL data types
The Content Services GraphQL API uses some standard scalar types, which are defined by the GraphQL specification, and some custom scalar types to hold data values.
Interfaces and output types
The schema defines many interfaces that match the CE class hierarchy, for example Containable, Versionable, and Document. In some cases, the instantiable output types in the schema simply represent the concrete type that implements these interfaces, for example, DocumentType.
Configuring security against Cross-Site Request Forgery (CSRF)
Because Content Services GraphQL API is a stateless application, you must configure a token exchange for your applications to protect against Cross-Site Request Forgery (CSRF) attacks.
Search API considerations
Note the following considerations when using the search API.
Mutation considerations
Most mutations (except those that create new objects) allow an Update Sequence Number (USN) to be specified through an updateSequenceNumber argument.
Batching support
Multiple mutations can be specified in a single GraphQL request. An UpdatingBatch is used automatically on the server to execute these mutations in a single transactional batch.
Returning related objects after batched changes
There are details in how changes involving multiple related objects are executed in a batch that may affect how the output data is shaped and returned from the corresponding mutations. This may involve batches that the user directly controls, by issuing multiple mutations in a single GraphQL request. It may also involve batches implicitly used internally when executing a mutation.
Downloading content
You can download content from the GraphQL API by using the content download endpoint.
Uploading content
Several document mutations allow content to be uploaded, along with other changes to the document.
Metadata types and secondary objects
In general, ClassDescription types and their embedded PropertyDescription types are served out of the metadata cache by the API.
Additional object change actions
The API currently exposes a few convenience mutations for certain core types in the CE object model. It is possible to perform a variety of other change actions using the generic changeObject() mutation.
Page size of enumeration properties
The API uses a default page size of 50 to return the results for any enumeration style properties.
Content Event Webhook support
Content Services 5.5.4 includes a new feature Content Event Webhook. The GraphQL API includes queries and mutations for registering and managing these event actions and subscriptions. For details, see Content Event Webhook examples.
Dependent object list editing
You can edit the dependent objects lists instead of replacing the entire list with new objects in a dependent objects list.
Metadata authoring
The Content Services GraphQL API supports authoring new metadata in the Content Engine.
Known constraints and limitations
Note the following limitations for using GraphQL API.
Example queries and mutations
You can use the following example queries and mutations to get started with Content Services GraphQL API development.
Content Event Webhook examples
You can use the following example queries and mutations to get started with the Content Event Webhook feature.
Metadata authoring examples
Metadata authoring examples retrieve property template, class definitions, shape, and define choice lists, property templates, class definitions, property definitions of a class definition.