Using the DELETE HTTP Method with cURL | PHP Code Examples

Using the DELETE HTTP Method in cURL Requests

The HTTP methods used are essential when building applications that interact with RESTful APIs. One of the essential HTTP methods in RESTful APIs is DELETE. PHP cURL is a popular library developer who sends HTTP requests from PHP to other servers. This article will provide a step-by-step guide on using PHP cURL to send DELETE requests to RESTful APIs.

In this article, you will learn how to use the PHP cURL DELETE HTTP method to delete data from an API. We will start with HTTP methods in RESTful APIs, then walk you through setting up your PHP environment and building a PHP script to delete data from an API.

cURL Delete Method PHP Code Example

<?php

$curl_handle = curl_init();

curl_setopt($curl_handle, CURLOPT_CUSTOMREQUEST, 'DELETE');
curl_setopt($curl_handle, CURLOPT_URL, 'http://api.example.com/resource/id');
curl_setopt($curl_handle, CURLOPT_USERPWD, 'username:password');
curl_setopt($curl_handle, CURLOPT_HTTPHEADER, [
    'Content-Type: application/json',
    'Authorization: Bearer your_access_token'
]);

$response = curl_exec($curl_handle);

if ($response === false) {
    echo 'Error: ' . curl_error($curl_handle);
} else {
    $decoded_response = json_decode($response, true);
    // Process the decoded response according to your application's requirements
    echo 'Response: ' . print_r($decoded_response, true);
}

curl_close($curl_handle);

?>

Steps to using the Delete method in cURL

1. Initialize a cURL session: Start a new cURL session using PHP’s curl_init() function.
2. Set the DELETE method: Configure the cURL session to use the DELETE method by setting the CURLOPT_CUSTOMREQUEST option.
3. Specify the API URL: Provide the API endpoint URL where the resource you want to delete is located using the CURLOPT_URL option.
4. Add authentication (if required): If the API requires authentication, add the credentials using the appropriate cURL options, such as CURLOPT_HTTPHEADER for API keys or CURLOPT_USERPWD for basic authentication.
5. Handle headers and content type: Set any required headers and the content type using the CURLOPT_HTTPHEADER option.
6. Execute the cURL session: Send the DELETE request to the API by calling the curl_exec() function.
7. Process the API response: Handle the API response by decoding the response, checking for errors, and performing any necessary processing.
8. Close the cURL session: Clean up the cURL session by calling the curl_close() function.

Article Highlights

• PHP cURL allows you to send DELETE requests to RESTful APIs, enabling you to manage resources effectively within your application.
• The DELETE method is essential for removing resources such as users, posts, or products by specifying the appropriate API endpoint.
• Building a PHP script to delete data from an API using cURL involves initializing a cURL session, configuring cURL options, executing the session, processing the API response, and closing the session.
• Troubleshooting common issues includes checking for insufficient permissions, verifying the API endpoint, resolving timeout or connectivity issues, and handling API-specific errors.
• Best practices for using the DELETE method with PHP cURL include ensuring proper authentication and authorization, validating and sanitizing user input, handling errors and reporting, and managing API rate limits.

Table of Contents

In this article, we will cover the following topics.

1. What are the HTTP methods in RESTful APIs?
2. Why Use the DELETE HTTP method?
3. Risks of using the DELETE HTTP method.
4. When to use the DELETE HTTP method?
5. When to avoid the DELETE HTTP method?
6. Setting Up cURL in PHP.
7. Step-by-step Guide to Using cURL with DELETE delete data from an API.
8. Example: Deleting data from a RESTful API using PHP cURL.
9. PHP cURL: Use the DELETE HTTP Method to delete data from the API Summary.

What are the HTTP methods in RESTful APIs

RESTful APIs (Representational State Transfer APIs) use standard HTTP methods to interact with resources on a server. These methods provide a simple and consistent way to perform CRUD (Create, Read, Update, and Delete) operations in web applications. 

The primary HTTP methods used in RESTful APIs are:

HTTP Method	Description
GET	Retrieve a resource or a collection of resources
POST	Create a new resource or add to a collection of resources
PUT	Replace an existing resource or create a new resource if it doesn’t exist
PATCH	Update a portion of an existing resource
DELETE	Remove a resource

Why Use the DELETE HTTP method

The DELETE HTTP method is important for following the best practices in RESTful API development. It tells the API when a resource needs to be removed or deleted. This is a double-edged sword as opening up this method for consumption can cause potential risks to your data. Always remember to practice to follow good authentication & authorization practices.

Here are some detailed reasons for using the DELETE method:

• Resource Management
• User Control
• Data Integrity
• Compliance with regulations

Risks of using the DELETE HTTP method

The DELETE HTTP method can pose risks if not implemented and managed correctly: This is why we recommend you follow really strong security & authentication practices whenever implementing this method. It can risk data loss, security vulnerabilities & cascading effects.

• Accidental deletion: Using the DELETE method without proper authentication and authorization controls can lead to accidental deletion of important data or resources.
• Data loss: The DELETE method permanently removes a resource from the server. If the resource is not properly backed up, it may result in permanent data loss.
• Unauthorized deletion: Malicious users may attempt to use the DELETE method to remove data or resources that they are not authorized to delete.
• Lack of recovery options: Once a resource is deleted using the DELETE method, it may not be possible to recover it.
• Cascading deletions: When a resource is deleted using the DELETE method, any related resources that depend on it may also be deleted. This can cause unintended consequences if the dependencies are not properly managed.

These risks can be mitigated by implementing proper authentication and authorization controls, implementing proper backups and disaster recovery procedures, and carefully managing resource dependencies.

When to use & avoid the DELETE HTTP method

Using the DELETE HTTP method is appropriate in certain situations. Here are some more detailed explanations of when to use the DELETE method:

You should use the DELETE HTTP method when:

When to use	When not to use
To delete a resource or a collection of resources	When the resource should not be deleted or when deleting the resource violates a business rule or a legal requirement
When the deletion operation is idempotent, meaning it can be safely repeated multiple times without causing any harm	When the deletion operation is non-idempotent, meaning it can cause harm if it’s repeated multiple times
When the deletion operation is reversible and can be undone if necessary	When the deletion operation is irreversible and cannot be undone
When the deletion operation is explicitly requested by the client through a DELETE request method	When the deletion operation is triggered by a GET request method or other HTTP request methods

It’s important to consider the DELETE method’s consequences before implementing it in an API. If there is any doubt about whether or not to use the DELETE method, it’s best to consult with other stakeholders and follow best practices for API design.

Setting Up cURL in PHP

Before you start using PHP cURL to delete data from an API, you must set up your PHP environment.

Click here for our start to finish guide on setting up cURL with PHP

How to Use cURL with DELETE to remove data from an API

This section will provide a step-by-step example of using cURL with the DELETE method to delete data from an API.

To build a PHP script that uses cURL to delete data from an API, follow these steps:

Step 1: Initializing a cURL session

First, you must initialize a cURL session using the curl_init() function. This function returns a cURL handle that you’ll use to configure and execute the DELETE request.

$curl_handle = curl_init();

Step 2: Configuring cURL options for the DELETE request

After initializing the cURL session, you must configure the cURL options for the DELETE request.

1. Setting the DELETE method

Use the CURLOPT_CUSTOMREQUEST option to specify the DELETE method for the cURL request:

curl_setopt($curl_handle, CURLOPT_CUSTOMREQUEST, 'DELETE');

2. Specifying the API URL

Set the API URL using the CURLOPT_URL option. Replace ‘http://api.example.com/resource/id’ with the actual URL of the API endpoint you want to send the DELETE request to:

curl_setopt($curl_handle, CURLOPT_URL, 'http://api.example.com/resource/id');

3. Adding authentication (if required)

If the API requires authentication, you need to provide the necessary credentials. For example, if the API uses Basic Authentication, you can set the CURLOPT_USERPWD option with your username and password:

curl_setopt($curl_handle, CURLOPT_USERPWD, 'username:password');

Replace ‘username:password’ with your actual API credentials. You may need to set the appropriate headers for other authentication methods, such as token-based authentication (see step 4).

4. Handling headers and content type:

You might need to set additional headers or specify the content type for the DELETE request. Use the CURLOPT_HTTPHEADER option to set an array of headers:

curl_setopt($curl_handle, CURLOPT_HTTPHEADER, [
    'Content-Type: application/json',
    'Authorization: Bearer your_access_token'
]);

Step 3: Executing the cURL session

Once you’ve configured the cURL options, you can execute the cURL session by calling the curl_exec() function. This function sends the DELETE request to the API and returns the response. If there’s an error, it returns false.

$response = curl_exec($curl_handle);

Step 4: Processing the API response

After executing the cURL session, you need to process the API response.

Decoding the response.

Most APIs return data in JSON format. To decode the JSON response into a PHP array or object, use the json_decode() function. Pass the $response variable to the function and set the second parameter to true if you want to return an associative array, or leave it as false (default) to return an object:

$decoded_response = json_decode($response, true);

Handling errors.

Check if the cURL request has resulted in errors using the curl_error() function. If there’s an error, it returns a string describing the error; otherwise, it returns an empty string.

if ($response === false) {
    echo 'Error: ' . curl_error($curl_handle);
} else {
    echo 'Response: ' . $response;
}

Additionally, you may want to check for errors in the decoded API response. Typically, APIs include an error message or status code in response to indicate errors. Handle these errors according to your application’s requirements.

Step 5: Closing the cURL session

Once you’ve executed the cURL session and processed the API response, closing the cURL session is essential to free up resources.

Use the curl_close() function to close the session:

curl_close($curl_handle);

Complete Code Example:

Here’s the complete example of a PHP script that uses cURL to delete data from an API:

<?php

$curl_handle = curl_init();

curl_setopt($curl_handle, CURLOPT_CUSTOMREQUEST, 'DELETE');
curl_setopt($curl_handle, CURLOPT_URL, 'http://api.example.com/resource/id');
curl_setopt($curl_handle, CURLOPT_USERPWD, 'username:password');
curl_setopt($curl_handle, CURLOPT_HTTPHEADER, [
    'Content-Type: application/json',
    'Authorization: Bearer your_access_token'
]);

$response = curl_exec($curl_handle);

if ($response === false) {
    echo 'Error: ' . curl_error($curl_handle);
} else {
    $decoded_response = json_decode($response, true);
    // Process the decoded response according to your application's requirements
    echo 'Response: ' . print_r($decoded_response, true);
}

curl_close($curl_handle);

?>

The above PHP code script initializes a cURL session, configures the options for the DELETE request, executes the request, and outputs the response or any errors that may occur. 

Make sure to replace the example API URL, authentication credentials, and headers with the appropriate values for the API you’re working with.

Example: Deleting data from a RESTful API using PHP cURL

Now that you have learned how to build a PHP script for the DELETE request, let’s see a complete example of deleting data from a RESTful API using PHP cURL.

In this example, we will walk through deleting data from a RESTful API using PHP cURL.

Step 1: Identifying the API endpoint

Before writing the PHP script, identify the API endpoint to which you will send the DELETE request. The endpoint is typically a URL representing a specific resource, such as a user, a blog post, or a product. 

For example, an API for managing blog posts might have the following endpoint for deleting a specific post:

https://api.example.com/posts/{post_id}

Replace {post_id} with the post ID you want to delete.

Step 2: Writing the PHP script for the DELETE request

Create a new PHP script called delete_post.php and use the following code as a starting point:

<?php

$curl_handle = curl_init();

$post_id = 123; // Replace with the actual post ID you want to delete
$api_url = 'https://api.example.com/posts/' . $post_id;

curl_setopt($curl_handle, CURLOPT_CUSTOMREQUEST, 'DELETE');
curl_setopt($curl_handle, CURLOPT_URL, $api_url);
curl_setopt($curl_handle, CURLOPT_HTTPHEADER, [
    'Content-Type: application/json',
    'Authorization: Bearer your_access_token' // Replace with your actual access token
]);

$response = curl_exec($curl_handle);

if ($response === false) {
    echo 'Error: ' . curl_error($curl_handle);
} else {
    $decoded_response = json_decode($response, true);
    // Process the decoded response according to your application's requirements
    echo 'Response: ' . print_r($decoded_response, true);
}

curl_close($curl_handle);

?>

Replace the $post_id variable with the post ID you want to delete. Update the $api_url variable with the API endpoint, and replace ‘your_access_token’ with your access token if required.

Step 3: Testing the script and verifying the deletion

To test the script, run it using the command line or a web server:

Command line.

Navigate to the folder containing the delete_post.php script and execute the following command:

php delete_post.php

The script should output the API response, indicating whether the deletion was successful.

Web server.

If you have a web server with PHP support, you can place the delete_post.php script in the web server’s document root and access it through your browser or an API testing tool like Postman.

For example, if the script is located in the document root, you can access it using the following URL:

http://localhost/delete_post.php

The script should output the API response in your browser or API testing tool, indicating whether the deletion was successful or not.

After testing the script, you can verify the deletion by trying to retrieve the deleted resource using the API’s GET method. If the deletion was successful, the API should return a 404 Not Found status code or a similar error indicating that the resource no longer exists.

PHP cURL: Use the DELETE HTTP Method to delete data from the API Summary

This article explored using PHP cURL to send DELETE requests to RESTful APIs, which is essential for managing resources within an application. The DELETE method allows you to remove resources such as users, posts, or products by specifying the appropriate API endpoint.

The key steps to building a PHP script that deletes data from an API using cURL are:

1. Setting up the PHP environment with cURL extension enabled.
2. Initializing a cURL session.
3. Configuring cURL options for the DELETE request, including setting the DELETE method, specifying the API URL, adding authentication (if required), and handling headers and content types.
4. Executing the cURL session and processing the API response, including decoding the response and handling errors.
5. Closing the cURL session.

Additionally, we covered common issues, best practices, and troubleshooting techniques to ensure a successful implementation. These include ensuring proper authentication and authorization, validating user input, handling errors and reporting, and managing API rate limits.

The article also provided examples for deleting data from a RESTful API using PHP cURL and troubleshooting common issues. 

By following these steps and adhering to the best practices outlined in this article, developers can create robust, secure, and efficient PHP applications that effectively use the DELETE method with cURL to delete data from RESTful APIs.

Continue Learning About cURL

This article is part of a more extensive series on using cURL in PHP. Feel free to browse through the articles to dig deeper into the topic.

• What is cURL used for
• Install cURL Libraries for PHP on AWS EC2 From Start to Finish
• POST cURL Body from File: PHP Code Examples ( JSON, CSV )
• How to Send a cURL GET Request
• 10 HTTP cURL Request Questions Answered
• Fetching Data from a REST API in PHP
• How to Post JSON Payload in cURL
• cURL Requests: Add Authorization Headers
• using cURL with Bearer Authorization Tokens
• using cURL with Self-Signed Certificates