Call a REST API in PHP

Our client had given me a REST API to which I need to make a PHP call to. But as a matter of fact the documentation given with the API is very limited, so I don't really know how to call the service.

I've tried to Google it, but the only thing that came up was an already expired Yahoo! tutorial on how to call the service. Not mentioning the headers or anything in depth information.

Is there any decent information around how to call a REST API, or some documentation about it? Because even on W3schools, they only describes the SOAP method. What are different options for making rest API in PHP?

Solution 1:

You can access any REST API with PHPs cURL Extension. However, the API Documentation (Methods, Parameters etc.) must be provided by your Client!

Example:

// Method: POST, PUT, GET etc
// Data: array("param" => "value") ==> index.php?param=value

function CallAPI($method, $url, $data = false)
{
    $curl = curl_init();

    switch ($method)
    {
        case "POST":
            curl_setopt($curl, CURLOPT_POST, 1);

            if ($data)
                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            break;
        case "PUT":
            curl_setopt($curl, CURLOPT_PUT, 1);
            break;
        default:
            if ($data)
                $url = sprintf("%s?%s", $url, http_build_query($data));
    }

    // Optional Authentication:
    curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    curl_setopt($curl, CURLOPT_USERPWD, "username:password");

    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

    $result = curl_exec($curl);

    curl_close($curl);

    return $result;
}

Solution 2:

If you have a url and your php supports it, you could just call file_get_contents:

$response = file_get_contents('http://example.com/path/to/api/call?param1=5');

if $response is JSON, use json_decode to turn it into php array:

$response = json_decode($response);

if $response is XML, use simple_xml class:

$response = new SimpleXMLElement($response);

http://sg2.php.net/manual/en/simplexml.examples-basic.php

Solution 3:

Use Guzzle. It's a "PHP HTTP client that makes it easy to work with HTTP/1.1 and takes the pain out of consuming web services". Working with Guzzle is much easier than working with cURL.

Here's an example from the Web site:

$client = new GuzzleHttp\Client();
$res = $client->get('https://api.github.com/user', [
    'auth' =>  ['user', 'pass']
]);
echo $res->getStatusCode();           // 200
echo $res->getHeader('content-type'); // 'application/json; charset=utf8'
echo $res->getBody();                 // {"type":"User"...'
var_export($res->json());             // Outputs the JSON decoded data