Handling HTTP requests and responses in CodeIgniter

In CodeIgniter, you can handle HTTP requests and responses within your controllers. Here's a guide on how to handle HTTP requests and responses:

Handling HTTP Requests:

1. Accessing Request Data:

   • Use CodeIgniter's input class to access request data such as GET, POST, PUT, DELETE parameters.
   • Example:

    // Getting POST data
   $post_data = $this->input->post();
   
   // Getting GET data
   $get_data = $this->input->get();
   
   // Getting PUT data (via PHP input stream)
   parse_str(file_get_contents("php://input"), $put_data);
   
   // Getting DELETE data (similar to PUT)
   

2. Determining Request Method:

   • Use the method() method of the input class to determine the HTTP request method.
   • Example:

   $http_method = $this->input->method(); 

Handling HTTP Responses:

1. Setting Response Headers:

   • Use CodeIgniter's output class to set HTTP response headers.
   • Example:

   $this->output->set_content_type('application/json'); 

2. Returning JSON Response:

   • Use json_encode() to encode data as JSON and set it as the response.
   • Example:

    $data = array('key' => 'value');
   $json_response = json_encode($data);
   $this->output->set_output($json_response);
   

3. Returning HTML Response:

   • Use CodeIgniter's view loading mechanism to load and display HTML views as responses.
   • Example:

    $this->load->view('my_view', $data); 

4. Returning Other Types of Responses:

   • Use appropriate methods of the output class to set the response content type and output data accordingly.
   • Example:

   $this->output->set_content_type('text/plain')->set_output('Hello, World!');
    

Example Controller Method:

public function handle_request() {
    // Determine HTTP method
    $http_method = $this->input->method();

    // Handle different HTTP methods
    switch ($http_method) {
        case 'get':
            // Handle GET request
            break;
        case 'post':
            // Handle POST request
            break;
        case 'put':
            // Handle PUT request
            break;
        case 'delete':
            // Handle DELETE request
            break;
        default:
            // Handle unsupported request
            break;
    }

    // Set response content type and output data
    $this->output
        ->set_content_type('application/json')
        ->set_output(json_encode($response_data));
}