Bullet is a functional PHP micro-framework that helps you easily create REST APIs and web applications that automatically conform to the requirements of the HTTP specification. Bullet is resource and URI-oriented and comes pre-loaded with powerful HTTP features like content-negotiation and caching.
404 error will be returned (path
was not found).405 “Method Not Allowed” response
will be returned (if the request is a POST, but you only have a GET handler).406 “Not Acceptable” response will
be returned (if ‘xml’ is requested, but you only have a ‘json’ handler).Super flexible routing. Because of the way the routing callbacks are
nested, Bullet’s routing system is one of the most flexible of any other PHP
framework or library. You can build any URL you want and respond to any HTTP
method on that URL. Routes are not restricted to specific patterns or URL
formats, and do not require a controller with specific method names to
respond to specific HTTP methods. You can nest routes as many levels deep as
you want to expose nested resources like posts/42/comments/943/edit with a
level of ease and elegance not found elsewhere.
Reduced code duplication (DRY). Bullet takes full advantage of its nested
closure routing system to reduce a lot of typical code duplication required
in most other frameworks. In a typical MVC framework controller, some code
has to be duplicated across methods that perform CRUD operations to run ACL
checks and load required resources like a Post object to view, edit or delete.
With Bullet’s nested closure style, this code can be written just once in a
path or param callback, and then you can use the loaded object in subsequent
path, param, or HTTP method handlers. This eliminates the need for “before”
hooks and filters, because you can just run the checks and load objects you
need before you define other nested paths and use them when required.
Bullet is not your typical PHP micro framework. Instead of defining a full
path pattern or a typical URL route with a callback and parameters mapped
to a REST method (GET, POST, etc.), Bullet parses only ONE URL segment
at a time, and only has two methods for working with paths: path and
param. As you may have guessed, path is for static path names like
“blog” or “events” that won’t change, and param is for variable path
segments that need to be captured and used, like “42” or “my-post-title”.
You can then respond to paths using nested HTTP method callbacks that
contain all the logic for the action you want to perform.
This type of unique callback nesting eliminates repetitive code for loading records, checking authentication, and performing other setup work found in typical MVC frameworks or other microframeworks where each callback or action is in a separate scope or class method.
$app = new Bullet\App(array( 'template.cfg' => array('path' => __DIR__ . '/templates') )); // 'blog' subdirectory $app->path('blog', function($request) use($app) { $blog = somehowGetBlogMapper(); // Your ORM or other methods here // 'posts' subdirectory in 'blog' ('blog/posts') $app->path('posts', function() use($app, $blog) { // Load posts once for handling by GET/POST/DELETE below $posts = $blog->allPosts(); // Your ORM or other methods here // Handle GET on this path $app->get(function() use($posts) { // Display all $posts return $app->template('posts/index', compact('posts')); }); // Handle POST on this path $app->post(function() use($posts) { // Create new post $post = new Post($request->post()); $mapper->save($post); return $this->response($post->toJSON(), 201); }); // Handle DELETE on this path $app->delete(function() use($posts) { // Delete entire posts collection $posts->deleteAll(); return 200; }); }); }); // Run the app and echo the response echo $app->run("GET", "blog/posts");
Perhaps the most compelling use of URL routing is to capture path
segments and use them as parameters to fetch items from a database, like
/posts/42 and /posts/42/edit. Bullet has a special param handler
for this that takes two arguments: a test callback that validates the
parameter type for use, and and a Closure callback. If the test
callback returns boolean false, the closure is never executed, and the
next path segment or param is tested. If it returns boolean true, the
captured parameter is passed to the Closure as the second argument.
Just like regular paths, HTTP method handlers can be nested inside param callbacks, as well as other paths, more parameters, etc.
$app = new Bullet\App(array( 'template.cfg' => array('path' => __DIR__ . '/templates') )); $app->path('posts', function($request) use($app) { // Integer path segment, like 'posts/42' $app->param('int', function($request, $id) use($app) { $app->get(function($request) use($id) { // View post return 'view_' . $id; }); $app->put(function($request) use($id) { // Update resource $post->data($request->post()); $post->save(); return 'update_' . $id; }); $app->delete(function($request) use($id) { // Delete resource $post->delete(); return 'delete_' . $id; }); }); // URL slug (alphanumeric with dashes and underscores) $app->param('slug', function($request, $slug) use($app) { return $slug; // 'my-post-title' }); }); // Results of above code echo $app->run('GET', '/posts/42'); // 'view_42' echo $app->run('PUT', '/posts/42'); // 'update_42' echo $app->run('DELETE', '/posts/42'); // 'delete_42' echo $app->run('DELETE', '/posts/my-post-title'); // 'my-post-title'
Bullet has built-in support for returning JSON responses. If you return
an array from a route handler (callback), Bullet will assume the
response is JSON and automatically json_encode the array and return the
HTTP response with the appropriate Content-Type: application/json header.
$app->path('/', function($request) use($app) { $app->get(function($request) use($app) { // Links to available resources for the API $data = array( '_links' => array( 'restaurants' => array( 'title' => 'Restaurants', 'href' => $app->url('restaurants') ), 'events' => array( 'title' => 'Events', 'href' => $app->url('events') ) ) ); // Format responders $app->format('json', function($request), use($app, $data) { return $data; // Auto json_encode on arrays for JSON requests }); $app->format('xml', function($request), use($app, $data) { return custom_function_convert_array_to_xml($data); }); $app->format('html', function($request), use($app, $data) { return $app->template('index', array('links' => $data)); }); }); });
Content-Type:application/json
{"_links":{"restaurants":{"title":"Restaurants","href":"http:\/\/yourdomain.local\/restaurants"},"events":{"title":"Events","href":"http:\/\/yourdomain.local\/events"}}}
Since you explicitly return values from Bullet routes instead of
sending output directly, nested/sub requests are straightforward and easy.
All route handlers will return Bullet\Response instances (even if they
return a raw string or other data type, they are wrapped in a response
object by the run method), and they can be composed to form a single
HTTP response.
$app = new Bullet\App(); $app->path('foo', function($request) use($app) { return "foo"; }); $app->path('bar', function($request) use($app) { $foo = $app->run('GET', 'foo'); // $foo is now a `Bullet\Response` instance return $foo->content() . "bar"; }); echo $app->run('GET', 'bar'); // echos 'foobar' with a 200 OK status
To run the Bullet test suite, simply run phpunit in the root of the
directory where the bullet files are in. Please make sure to add tests
and run the test suite before submitting pull requests for any contributions.
Bullet - and specifically path-based callbacks that fully embrace HTTP and encourage a more resource-oriented design - is something I have been thinking about for a long time, and was finally moved to create it after seeing @joshbuddy give a presentation on Renee (Ruby) at Confoo 2012 in Montréal.