Response transformation (transform) functions are called right after a request returns successfully, and allow a page author to transform / augment the response to a form expected by the caller.

The ServiceDataProvider supports a predefined list of response transformation function types, described in this section. Note that there are no guarantees of the order in which transform functions are called.

Signature

A response transformation function has the following signature: function (result). It can be defined on the service endpoint, but can also be overridden on the variable.

function(configuration, transformsContext) { 

    // process the contents and return the result appropriate for the response transform
    return result; 
} 

Generally these functions are implemented by a service author and associated to the service, but the individual functions can also be overridden on the Service Data Provider variable or the Call Rest action.

The parameters to the function are:

• configuration: An object that has the following properties:
  • headers: The response headers.
  • body: The body returned in the response.
  • fetchConfiguration: the configuration pertaining to this fetch call. If fetch was initiated by ServiceDataProvider this includes the following properties:
    • capability: The fetch capability, like fetchByKeys, fetchFirst, fetchByOffset
    • context: a snapshot of the ServiceDataProvider variable state at the time the fetch call was made.
    • externalContext: if the fetch was externalized to a chain, then the context setup on the RestAction in that chain
    • fetchParameters: a snapshot of the original fetch parameters provided by the initiator of the fetch (such as a component). The parameters passed to the fetch call are defined by the JET Data Provider fetch API.
    • transformsOptions: these are full set of transforms options that are passed to each transform function. These are computed using the parameters configured on the Service Data Provider, the RestAction (if applicable), and the input parameters provided by initiator (such as the component).
• transformsContext: a context object that is passed to every transform function to store/retrieve any contextual information for the current request lifecycle.

The function returns a configuration object appropriate for the response transform type. See the following common response transform types (paginate transform, body transform) below for details on the returned responses.