Transform Request Body Policy

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

If the incoming request body isn't JSON, you can use request.text() or request.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 (request: ZuploRequest, context: ZuploContext) {
  // Get the incoming body as an Object
  const obj = await request.json();

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

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

  // Return a new request based on the
  // original but with the new body
  return new ZuploRequest(request, { body });
}

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-inbound",
  "policyType": "custom-code-inbound",
  "handler": {
    "export": "default",
    "module": "$import(./modules/transform-body-inbound)"
  }
}

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-inbound.
• 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