Laravel 5 REST API

Introduction

Almost all successful internet based companies have APIs. API is an acronym for Application Programming Interface. APIs allows different systems to communicate with one another. Let’s say you have developed an android application for our online store. The API can be used to retrieve data from the online store and display it in the mobile application. The API can also be used to process orders from remote clients such as mobile applications, other websites etc.

Topics to be covered

We will cover the following topics

• What is a RESTful API?
• REST API Best Practices
• Larashop API

What is a RESTful API?

REST is the acronym for Representational State Transition. It is a software architectural design for building scalable web services. REST APIs allow systems to communicate over HTTP using HTTP verbs. HTTP GET is used to get resources, POST used to create new resources, PUT to update existing ones and DELETE to delete existing resources.

REST API Best Practices

This is a summary from the blog post we posted on Kode Blog 10 REST API Design Best Practices That Will Make Developers Love Your API. Read the article for detailed explanations of this summary.

1. Best Practice # 1: Use HTTP VERBS to determine action to be taken
2. Best Practice # 2: API Versioning
3. Best Practice # 3: Use plurals to describe resources
4. Best Practice # 4: Use query strings to build relations
5. Best Practice # 5: Partial responses
6. Best Practice # 6: Response Codes and Error Handling
7. Best Practice # 7: Limit the number of request in a given time period from the same IP Address
8. Best Practice # 8: Use OAuth latest version for authentication
9. Best Practice # 9: use JSON as the default
10. Best Practice # 10: Cache GET results for less frequently changing data

Larashop API

For now, we will only display the products and categories. Our API will implement basic authentication only. Future tutorial updates will include more functionality.
Our API will have the following URLs. All the URLs will use the HTTP verb GET

S/N	Resource	URL	Description	Status Code
1	Product	/api/v1/products	List products	200
2	Product	/api/v1/products/1	List product with id 1	200
3	Category	/api/v1/categories	List categories	200
4	Category	/api/v1/categories/1	List category with id 1	200

Let’s now create the routes that will give us

1. Open /app/Http/routes.php
2. Add the following routes

// API routes...
Route::get('/api/v1/products/{id?}', ['middleware' => 'auth.basic', function($id = null) {
if ($id == null) {
    $products = App\Product::all(array('id', 'name', 'price'));
} else {
    $products = App\Product::find($id, array('id', 'name', 'price'));
}
return Response::json(array(
            'error' => false,
            'products' => $products,
            'status_code' => 200
        ));
}]);

Route::get('/api/v1/categories/{id?}', ['middleware' => 'auth.basic', function($id = null) {
if ($id == null) {
    $categories = App\Category::all(array('id', 'name'));
} else {
    $categories = App\Category::find($id, array('id', 'name'));
}
return Response::json(array(
            'error' => false,
            'user' => $categories,
            'status_code' => 200
        ));
}]);

HERE,

• Route::get('/api/v1/products/{id?}', ['middleware' => 'auth.basic', function($id = null) defines a RESTful URL for version 1 of the API. The requested resource is Products. {id?} specifies an optional parameter. The id is used to retrieve a single product. The API uses basic authentication
• The routes are calling the respective models to retrieve the data from the database.
• return Response::json(…) returns the results in JSON format.

Load the following URL in your web browser

http://localhost/larashop/public/api/v1/products

You will get the following basic Authentication login window

User a registered email address and password from the previous tutorial on Authetication You will get the following results

Summary

Building a basic REST API in Laravel is no more than retrieving data using models and formatting the response to JSON. The future tutorial updates will build a fairly complex API that will do more.