How to use the ApiController class

ApiController is a Controller for handling all integrations using the HttpRequest and HttpResponse classes in Apex. This simple guide explains how to use the class in your Apex code.

Prerequisites

Before using the ApiController, you need to ensure that:

• You have created a named credential to authenticate the API callout.

Deployment

You can use the quick installer here to deploy directly to your org.

Usage

To use the ApiController class, follow these steps:

1. Create an instance of the class:

ApiController api = new ApiController();

2. Initialize the controller with a named credential and a path:

api.init('named_credential', ApiController.HttpVerb.GET, '/path/to/resource');

Note that you need to specify the HttpVerb enum value to determine the HTTP method for the API callout.

3. Set additional parameters and add headers if necessary:

api.setTimeout(5000);
api.addHeader('Content-Type', 'application/json');

4. Add query parameters and a request body if necessary:

Map<String, String> queryParams = new Map<String, String>{
    'param1' => 'value1',
    'param2' => 'value2'
};
api.addQueryParameter(queryParams);

String requestBody = '{"key": "value"}';
api.addBody(requestBody);

5. Perform the API callout:

api.doCallout();

6. Retrieve the response from the controller:

HttpResponse response = api.getResponse();

Chainable example

You can also chain the methods together to create a more concise code. The only requirement is that you call the init method first, and then the doCallout method last. The getResponse method can be called after the doCallout method you require the response.

ApiController api = new ApiController();
api.init('named_credential', ApiController.HttpVerb.GET, '/path/to/resource')
    .setTimeout(5000)
    .addHeader('Content-Type', 'application/json')
    .addQueryParameter(
        new Map<String, String>{
            'param1' => 'value1',
            'param2' => 'value2'
        })
    .addBody('{"key": "value"}')
    .doCallout();

HttpResponse res = api.getResponse();