REST API Best Practices & Implementing in Codeigniter

REST API &
Implementing it in
CodeIgniter

Who Am I
• PHP Developer & Consultant
• Reviewed “Testing with Qunit”
• Helped to bring out thesis on “Business
Prospective of cloud computing”
• Founder of Website “WebGunny.com”
RIP Jun 2010 - Dec 2011

In this talk...
• Why REST API is a heart of every product
• REST API – As developer UI
• Best Practices of REST API
• REST API in codeigniter

Developer is your API customer

Building Developer Friendly API

Let’s Start with best practices
API End Point :
https://www.YourApp.com/Api/
OR
https://Api.YourApp.com/
Finally Format:
https://www.YourApp.com/Api/ResourceName

Identifying resources
• You can make the resources more sensible
based on your product
• For example
– Tasks
– Comments
– Notifications
– Users
– Projects
– Files

Make Use of HTTP Verbs
• GET /task - Retrieves a list of task
• GET /task/12 - Retrieves a specific task
• POST /task - Creates a new task
• PUT /task/12 - Updates task #12
• PATCH /task/12 - Partially updates task #12
• DELETE /task/ - Deletes all task
• DELETE /task/12 - Deletes task #12

Map the relationships
• GET /task/12/comments - Retrieves list of comments
for task #12
• GET /task /12/comments/5 - Retrieves comment #5 for
task #12
• POST /task /12/comments - Creates a new comments
in task #12
• PUT /task /12/comments/5 - Updates comments #5 for
task #12
• PATCH /task /12/comments/5 - Partially updates
comment #5 for task #12
• DELETE /task/12/comments/5 - Deletes comment #5
for task #12

Search Sort & Filter
• GET /tasks?sort=-priority - Retrieves a list of
task in descending order of priority
• GET /tasks?sort=-priority,created_at -
Retrieves a list of tasks in descending order of
priority then by date created

Aliases for common queries
To make the API experience more pleasant for
the average consumer
GET /tasks?status=completed
GET /tasks/recently_completed

Allow the fields to be selected
The API consumer doesn't always need the full
representation of a resource.
GET /task?fields=id,title,updated_at

Paging of data
Paging makes the API fast & responsive
GET /notification?page=1&per_page=50

Return full resource after action
• A PUT, POST or PATCH call may make
modifications to fields
• Return the updated (or created)
representation as part of the response.
• Prevent an API consumer from having to hit
the API again

Auto loading related
resources
{ "id" : 12,
“TaskName" : "I have a question!",
"summary" : "Hi, ....",
"customer" : { "name" : "Bob" },
assigned_user: { "id" : 42, "name" : "Jim", }
}

Make Error Message Friendly
• The API should always return sensible HTTP
status codes
• 400 series status codes for client issues & 500
series status codes for server issues
• API should standardize that all 400 series errors
come with consumable JSON error
representation
{ "code" : 1234,
"message" : “task field validation failed ",
"description" : “Due date is not set"
}

REST API in Codeigniter
UI/ Controller
Your App
Your API
Rest Client

What we need
• Codeigniter
• chriskacerguis/codeigniter-restserver
• Router implementation

Structuring the project
/application
/controller/
api/ //For all api controllers
/libraries //For the third-party libraries
REST_server.php
Format.php
/config //For all config files
Router.php
Rest_server.php

Router Implementation
//res/id/function/id --> res/function/id/num/sid/num
$route['api/([a-z_]+)/(:any)/([a-z_]+)/(:any)'] = 'api/$1/$3/id/$2/rid/$4';
//res/id/function --> res/function/id/num
$route['api/([a-z_]+)/(:any)/([a-z_]+)'] = 'api/$1/$3/id/$2';
//res/function --> res/function
$route['api/([a-z_]+)/([a-z_]+)'] = 'api/$1/$2/';
//res/id --> res/index/id/num
$route['api/([a-z_]+)/(:any)'] = 'api/$1/index/id/$2';
//res/ --> //res/
$route['api/([a-z_]+)'] = 'api/$1';

Creating a first API controller
require(APPPATH . '/libraries/Rest_Service.php');
class task extends REST_Service{
public function index_get() { //Logic }
public function index_post() { //Logic }
public function index_put() { //Logic }
public function index_patch() { //Logic }
public function index_delete() { //Logic }
}

Every Function has 2 Reaction
public function index_get() {
if($this->get('id'))
{
//Application Logic
$this->response($results,$code);
}
else
{
//Application Logic
$this->response($results,$code);
}
}

HTTP Action Vs SQL
• Get (select)
– Get All
– Get by ID
• Post (Insert)
• Put (update all fields )
• Patch (update selected fields)
• Delete (delete)
– Delete All
– Delete by ID

Summary
• REST API is heart of product
• REST API is a developer UI
• Follow the best practices of REST API
• Use “chriskacerguis/codeigniter-restserver” to
implement REST in codeigniter

Questions ?
Website:SachinGKulkarni.com
Twitter:@sachingk30
Email:sachingk.30@gmail.com

REST API Best Practices & Implementing in Codeigniter

In this document