ZF REST

Introduction

This module provides structure and code for quickly implementing RESTful APIs that use JSON as a transport.

It allows you to create RESTful JSON APIs that use the following standards:

• Hypermedia Application Language, aka HAL, used for creating JSON payloads with hypermedia controls.
• Problem Details for HTTP APIs, aka API Problem, used for reporting API problems.

Requirements

Please see the composer.json file.

Installation

Run the following composer command:

$ composer require "zfcampus/zf-rest:~1.0-dev"

Alternately, manually add the following to your composer.json, in the require section:

"require": {
    "zfcampus/zf-rest": "~1.0-dev"
}

And then run composer update to ensure the module is installed.

Finally, add the module name to your project's config/application.config.php under the modules key:

return array(
    /* ... */
    'modules' => array(
        /* ... */
        'ZF\Rest',
    ),
    /* ... */
);

Configuration

User Configuration

The top-level key used to configure this module is zf-rest.

Key: Controller Service Name

Each key under zf-rest is a controller service name, and the value is an array with one or more of the following keys.

Sub-key: collection_http_methods

An array of HTTP methods that are allowed when making requests to a collection.

Sub-key: entity_http_methods

An array of HTTP methods that are allowed when making requests for entities.

Sub-key: collection_name

The name of the embedded property in the representation denoting the collection.

Sub-key: collection_query_whitelist (optional)

An array of query string arguments to whitelist for collection requests and when generating links to collections. These parameters will be passed to the resource class' fetchAll() method. Any of these parameters present in the request will also be used when generating links to the collection.

Examples of query string arguments you may want to whitelist include "sort", "filter", etc.

Sub-key: controller_class (optional)

An alternate controller class to use when creating the controller service; it must extend ZF\Rest\RestController. Only use this if you are altering the workflow present in the RestController.

Sub-key: identifier (optional)

The name of event identifier for controller. It allows multiple instances of controller to react to different sets of shared events.

Sub-key: resource_identifiers (optional)

The name or an array of names of event identifier/s for resource.

Sub-key: entity_class

The class to be used for representing an entity. Primarily useful for introspection (for example in the Apigility Admin UI).

Sub-key: route_name

The route name associated with this REST service. This is utilized when links need to be generated in the response.

Sub-key: route_identifier_name

The parameter name for the identifier in the route specification.

Sub-key: listener

The resource class that will be dispatched to handle any collection or entity requests.

Sub-key: page_size

The number of entities to return per "page" of a collection. This is only used if the collection returned is a Zend\Paginator\Paginator instance or derivative.

Sub-key: max_page_size (optional)

The maximum number of entities to return per "page" of a collection. This is tested against the page_size_param. This parameter can be set to help prevent denial of service attacks against your API.

Sub-key: min_page_size (optional)

The minimum number of entities to return per "page" of a collection. This is tested against the page_size_param.

Sub-key: page_size_param (optional)

The name of a query string argument that will set a per-request page size. Not set by default; we recommend having additional logic to ensure a ceiling for the page size as well, to prevent denial of service attacks on your API.

User configuration example:

'AddressBook\\V1\\Rest\\Contact\\Controller' => array(
    'listener' => 'AddressBook\\V1\\Rest\\Contact\\ContactResource',
    'route_name' => 'address-book.rest.contact',
    'route_identifier_name' => 'contact_id',
    'collection_name' => 'contact',
    'entity_http_methods' => array(
        0 => 'GET',
        1 => 'PATCH',
        2 => 'PUT',
        3 => 'DELETE',
    ),
    'collection_http_methods' => array(
        0 => 'GET',
        1 => 'POST',
    ),
    'collection_query_whitelist' => array(),
    'page_size' => 25,
    'page_size_param' => null,
    'entity_class' => 'AddressBook\\V1\\Rest\\Contact\\ContactEntity',
    'collection_class' => 'AddressBook\\V1\\Rest\\Contact\\ContactCollection',
    'service_name' => 'Contact',
),

System Configuration

The zf-rest module provides the following configuration to ensure it operates properly in a Zend Framework 2 application.

'service_manager' => array(
    'invokables' => array(
        'ZF\Rest\RestParametersListener' => 'ZF\Rest\Listener\RestParametersListener',
    ),
    'factories' => array(
        'ZF\Rest\OptionsListener' => 'ZF\Rest\Factory\OptionsListenerFactory',
    ),
),

'controllers' => array(
    'abstract_factories' => array(
        'ZF\Rest\Factory\RestControllerFactory'
    )
),

'view_manager' => array(
    // Enable this in your application configuration in order to get full
    // exception stack traces in your API-Problem responses.
    'display_exceptions' => false,
),

ZF2 Events

Listeners

ZF\Rest\Listener\OptionsListener

This listener is registered to the MvcEvent::EVENT_ROUTE event with a priority of -100. It serves two purposes:

• If a request is made to either a REST entity or collection with a method they do not support, it will return a 405 Method not allowed response, with a populated Allow header indicating which request methods may be used.
• For OPTIONS requests, it will respond with a 200 OK response and a populated Allow header indicating which request methods may be used.

ZF\Rest\Listener\RestParametersListener

This listener is attached to the shared dispatch event at priority 100. The listener maps query string arguments from the request to the Resource object composed in the RestController, as well as injects the RouteMatch.

ZF2 Services

Models

ZF\Rest\AbstractResourceListener

This abstract class is the base implementation of a Resource listener. Since dispatching of zf-rest based REST services is event driven, a listener must be constructed to listen for events triggered from ZF\Rest\Resource (which is called from the RestController). The following methods are called during dispatch(), depending on the HTTP method:

• create($data) - Triggered by a POST request to a resource collection.
• delete($id) - Triggered by a DELETE request to a resource entity.
• deleteList($data) - Triggered by a DELETE request to a resource collection.
• fetch($id) - Triggered by a GET request to a resource entity.
• fetchAll($params = array()) - Triggered by a GET request to a resource collection.
• patch($id, $data) - Triggered by a PATCH request to resource entity.
• patchList($data) - Triggered by a PATCH request to a resource collection.
• update($id, $data) - Triggered by a PUT request to a resource entity.
• replaceList($data) - Triggered by a PUT request to a resource collection.

ZF\Rest\Resource

The Resource object handles dispatching business logic for REST requests. It composes an EventManager instance in order to delegate operations to attached listeners. Additionally, it composes request information, such as the Request, RouteMatch, and MvcEvent objects, in order to seed the ResourceEvent it creates and passes to listeners when triggering events.

Controller

ZF\Rest\RestController

This is the base controller implementation used when a controller service name matches a configured REST service. All REST services managed by zf-rest will use this controller (though separate instances of it), unless they specify a controller_class option. Instances are created via the ZF\Rest\Factory\RestControllerFactory abstract factory.

The RestController calls the appropriate method in ZF\Rest\Resource based on the requested HTTP method. It returns HAL payloads on success, and API Problem responses on error.