The issue is this:
I have a web application that runs on a PHP server. I'd like to build a REST api for it.
I did some research and I figured out that REST api uses HTTP methods (GET, POST...) for certain URI's with an authentication key (not necessarily) and the information is presented back as a HTTP response with the info as XML or JSON (I'd rather JSON).
My question is:
This question is related to
php
api
rest
authentication
That is pretty much the same as created a normal website.
Normal pattern for a php website is:
With a api, you just add a new step between 3 and 4. After 3, create a array with all information you need. Encode this array in json and exit or return this value.
$info = array("info_1" => 1; "info_2" => "info_2" ... "info_n" => array(1,2,3));
exit(json_encode($info));
That all for the api. For the client side, you can call the api by the url. If the api work only with get call, I think it's possible to do a simply (To check, I normally use curl).
$info = file_get_contents(url);
$info = json_decode($info);
But it's more common to use the curl library to perform get and post call. You can ask me if you need help with curl.
Once the get the info from the api, you can do the 4 & 5 steps.
Look the php doc for json function and file_get_contents.
curl : http://fr.php.net/manual/fr/ref.curl.php
EDIT
No, wait, I don't get it. "php API page" what do you mean by that ?
The api is only the creation/recuperation of your project. You NEVER send directly the html result (if you're making a website) throw a api. You call the api with the url, the api return information, you use this information to create the final result.
ex: you want to write a html page who say hello xxx. But to get the name of the user, you have to get the info from the api.
So let's say your api have a function who have user_id as argument and return the name of this user (let's say getUserNameById(user_id)), and you call this function only on a url like your/api/ulr/getUser/id.
Function getUserNameById(user_id)
{
$userName = // call in db to get the user
exit(json_encode($userName)); // maybe return work as well.
}
From the client side you do
$username = file_get_contents(your/api/url/getUser/15); // You should normally use curl, but it simpler for the example
// So this function to this specifique url will call the api, and trigger the getUserNameById(user_id), whom give you the user name.
<html>
<body>
<p>hello <?php echo $username ?> </p>
</body>
</html>
So the client never access directly the databases, that the api's role.
Is that clearer ?
As simon marc said, the process is much the same as it is for you or I browsing a website. If you are comfortable with using the Zend framework, there are some easy to follow tutorials to that make life quite easy to set things up. The hardest part of building a restful api is the design of the it, and making it truly restful, think CRUD in database terms.
It could be that you really want an xmlrpc interface or something else similar. What do you want this interface to allow you to do?
--EDIT
Here is where I got started with restful api and Zend Framework. Zend Framework Example
In short don't use Zend rest server, it's obsolete.
(1) How do I ... build those URI's? Do I need to write a PHP code at that URI?
There is no standard for how an API URI scheme should be set up, but it's common to have slash-separated values. For this you can use...
$apiArgArray = explode("/", substr(@$_SERVER['PATH_INFO'], 1));
...to get an array of slash-separated values in the URI after the file name.
Example: Assuming you have an API file api.php in your application somewhere and you do a request for api.php/members/3, then $apiArgArray will be an array containing ['members', '3']. You can then use those values to query your database or do other processing.
(2) How do I build the JSON objects to return as a response?
You can take any PHP object and turn it into JSON with json_encode. You'll also want to set the appropriate header.
header('Content-Type: application/json');
$myObject = (object) array( 'property' => 'value' ); // example
echo json_encode($myObject); // outputs JSON text
All this is good for an API that returns JSON, but the next question you should ask is:
(3) How do I make my API RESTful?
For that we'll use $_SERVER['REQUEST_METHOD'] to get the method being used, and then do different things based on that. So the final result is something like...
header('Content-Type: application/json');
$apiArgArray = explode("/", substr(@$_SERVER['PATH_INFO'], 1));
$returnObject = (object) array();
/* Based on the method, use the arguments to figure out
whether you're working with an individual or a collection,
then do your processing, and ultimately set $returnObject */
switch ($_SERVER['REQUEST_METHOD']) {
case 'GET':
// List entire collection or retrieve individual member
break;
case 'PUT':
// Replace entire collection or member
break;
case 'POST':
// Create new member
break;
case 'DELETE':
// Delete collection or member
break;
}
echo json_encode($returnObject);
Sources: https://stackoverflow.com/a/897311/1766230 and http://en.wikipedia.org/wiki/Representational_state_transfer#Applied_to_web_services
In 2013, you should use something like Silex or Slim
Silex example:
require_once __DIR__.'/../vendor/autoload.php';
$app = new Silex\Application();
$app->get('/hello/{name}', function($name) use($app) {
return 'Hello '.$app->escape($name);
});
$app->run();
Slim example:
$app = new \Slim\Slim();
$app->get('/hello/:name', function ($name) {
echo "Hello, $name";
});
$app->run();
Another framework which has not been mentioned so far is Laravel. It's great for building PHP apps in general but thanks to the great router it's really comfortable and simple to build rich APIs. It might not be that slim as Slim or Sliex but it gives you a solid structure.
See Aaron Kuzemchak - Simple API Development With Laravel on YouTube and
Laravel 4: A Start at a RESTful API on NetTuts+
I know that this question is accepted and has a bit of age but this might be helpful for some people who still find it relevant. Although the outcome is not a full RESTful API the API Builder mini lib for PHP allows you to easily transform MySQL databases into web accessible JSON APIs.
Source: Stackoverflow.com