Transform Response Body Policy

This example policy shows how to use response.json() to read the outgoing response as a JSON object. The object can then be modified as appropriate. It's then converted back to a string and a new Response is returned in the policy with the new body.

If the incoming response body isn't JSON, you can use response.text() or response.blob() to access the contents as raw text or a blob.

modules/my-policy.ts
import { ZuploContext, ZuploRequest } from "@zuplo/runtime";

export default async function (
  response: Response,
  request: ZuploRequest,
  context: ZuploContext,
) {
  // Get the outgoing body as an Object
  const obj = await response.json();

  // Modify the object as required
  obj.myNewProperty = "Hello World";

  // Stringify the object
  const body = JSON.stringify(obj);

  // Return a new response with the new body
  return new Response(body, request);
}

Configuration

The example below shows how to configure a custom code policy in the 'policies.json' document that utilizes the above example policy code.

config/policies.json
{
  "name": "transform-body-outbound",
  "policyType": "custom-code-outbound",
  "handler": {
    "export": "default",
    "module": "$import(./modules/transform-body-outbound)"
  }
}

Policy Configuration

• name <string> - The name of your policy instance. This is used as a reference in your routes.
• policyType <string> - The identifier of the policy. This is used by the Zuplo UI. Value should be transform-body-outbound.
• handler.export <string> - The name of the exported type. Value should be default.
• handler.module <string> - The module containing the policy. Value should be $import(./modules/YOUR_MODULE).

Using the Policy

Read more about how policies work