How do I deal with different content types (like XML) in Guzzle responses?

Guzzle is a PHP HTTP client that simplifies the process of making HTTP requests and processing HTTP responses. By default, Guzzle attempts to parse the response body of a request to determine the appropriate content type, but you may encounter situations where you need to manually handle different content types, such as XML.

Here's a step-by-step guide on dealing with different content types in Guzzle responses, with a focus on handling XML responses:

1. Make a request using Guzzle

First, you'll need to make a request using Guzzle. This is typically done by creating a client and then sending a request to a specific URI.

use GuzzleHttp\Client;

$client = new Client();
$response = $client->request('GET', 'http://example.com/data.xml');

2. Check the Content-Type of the Response

You can check the Content-Type header of the response to determine how to handle the body content.

$contentType = $response->getHeader('Content-Type');

3. Handle XML Content-Type

If the Content-Type indicates that the response is XML (e.g., application/xml or text/xml), you can process the body accordingly.

if (strpos($contentType[0], 'application/xml') !== false || strpos($contentType[0], 'text/xml') !== false) {
    $xmlBody = $response->getBody()->getContents();

    // Handle the XML string here
    // For example, you might convert it to a SimpleXMLElement object
    $xmlElement = new SimpleXMLElement($xmlBody);

    // Now you can work with the XML data
    // ...
}

4. Process XML Data

Once you have the XML string, you can parse it using PHP's SimpleXMLElement or DOMDocument classes.

Using SimpleXMLElement

$xmlElement = new SimpleXMLElement($xmlBody);

// Accessing XML nodes
foreach ($xmlElement->item as $item) {
    echo $item->title . "\n";
}

Using DOMDocument

$dom = new DOMDocument();
$dom->loadXML($xmlBody);

$items = $dom->getElementsByTagName('item');
foreach ($items as $item) {
    echo $item->getElementsByTagName('title')->item(0)->nodeValue . "\n";
}

5. Handling JSON or Other Content Types

If the response type is JSON or another content type, you can handle it similarly by checking the Content-Type header and using the appropriate PHP functions or classes to parse the content.

For JSON:

if (strpos($contentType[0], 'application/json') !== false) {
    $jsonBody = $response->getBody()->getContents();

    // Decode JSON string
    $data = json_decode($jsonBody, true);

    // Now you can work with the JSON data
    // ...
}

6. Error Handling

Always include error handling to manage situations where the content type is not as expected or when there are issues parsing the XML.

try {
    $xmlElement = new SimpleXMLElement($xmlBody);
    // Process the XML
} catch (Exception $e) {
    // Handle the error
    echo "Error parsing XML: " . $e->getMessage();
}

By following these steps, you can effectively manage different content types in Guzzle responses, including XML. Always ensure that you have error handling in place to deal with any issues that may arise during the parsing of the response body.