Basic of Codeigniter

Speaker:

 JhA KUMAR PANKA J

Our Agenda ➢

What is CodeIgniter ?

➢

What makes CodeIgniter a smart framework to use?

➢

Why MVC?

➢

Routing Basics

➢

Installation and Configuration

➢

Model View Controller

➢

Template Integration

➢

Template Engine

What is CodeIgniter ? ➢

A proven, agile & open PHP web application fr amework

➢

Enables developers to build web applications faster

➢

Offers many helpful code libraries and helpers

➢

Based on MVC design pattern

➢

Developed by EllisLab

What makes CodeIgniter a smart framework? ➢

Exceptional performance

➢

MVC approach to development

➢

Generates search engine friendly clean URLs

➢

Easily extensible

➢

Runs on both PHP 4 (4.3.2+) and 5

➢

Support for most major databases including MySQL (4.1+), MySQLi, MS SQL, Postgres, Oracle, SQLite, and ODBC.

➢

Application security is a focus

➢

Easy caching operations

➢

Many libraries and helpers to help you with complex operations such as email, image manipulation,form validation etc

➢

Most libraries are only loaded when needed which cuts back on resources needed

Why MVC? ➢

MVC stands for Model, View, Controller

➢

Model:  Model:  The model deals with the raw data and database interaction. Component is not required and can be included in the controller.

➢

View:  View:  The view deals with displaying the data and interface controls to the user.

➢

Controller: The controller acts as the in between of view and model.The controller is the place to load libraries and helpers.

Routing Basics

[ GlobAl CodESTER

Installation and Configuration

]

Download CodeIgniter ➢

Download CodeIgniter and upload it to your server. http://ellislab.com/codeigniter/download

➢

 All you need to do is unzip and up load it to your PHP and MySQL enabled server.

CI Directory Structure ➢

The application directory contains model,view,controller,helper,library model,view,controller,helper,library and so on.

➢

The system directory is the core and consists of the core framework files. When a new version is released, you can update your existing application just by replacing this system directory with the latest release.

➢

The user_guide houses user_guide houses the user guide to CI.

➢

The index.php file index.php file is the bit that does all the CI magic.

Application Directory Structure ➢

cache folder stores all the caches generated by the caching library. The cache folder

➢

This config directory config  directory includes settings/configuration related information like database settings, route information etc.

➢

The core directory needed to extend the functionality of core classes like controller,loader,router etc.

➢

The errors folder stores all the template error pages for the application.

➢

The helpers folder stores all the helpers which are specific to your application like email, imageMagick etc.

➢

The hooks folder is for hooks which modify the functioning of CI’s core files.

➢

The language folder stores lines of text which can be loaded through the language library to create multilingual sites.

➢

The libraries folder stores all the libraries which are specific to your application.

➢

The third_party directory third_party directory will include library files, but only those, which are imported from third-party.

System Directory Structure ➢

The database folder stores all the database drivers and class which enable you to connect to database.

➢

The fonts folder fonts folder stores all the fonts which can be used by the image manipulation library.

➢

The helpers folder helpers folder stores all of CI’s core helpers but you can place your own helpers in here which can be accessed by all of your applications.

➢

The language folder stores all of CI’s core language files which its libraries and helpers use.

➢

The libraries folder stores all of CI’s core libraries but you can place your own libraries.

Configuration ➢

Need to set up “base_url” up “base_url”.. To do this, open up system/application/config/config.php

➢

Need to set up “database “ database”” To use a database, open up system/application/config/database.php

➢

Add “database “database”” to the autoload libraries To do this, open up system/application/config/autoload.php

Testing CodeIgniter

 y !  l  l  f u  s  s  c c e  u  s  e r    t t  i  g n  I g  e  o d  C  r e d  u  g  i g  n f  o  u c  o  n , y    o o  i  a t  l  u  r a t  g  n  C o

[ GlobAl CodESTER

Model View Controller

]

What is a controller? A Controller is simply a class file that is named in a way that can be associated with a URI. http://localhost/news_system/index.php/news http://localhost/news_system/index.php/ news Here CI will find news.php  Controller 

Let's create a simple news controller so you can see it in action. Then save the file “news.php” to “application/controllers/” folder.  class News extends CI_Controller { public function __construct() {   parent::__construct();   $this->load->model('news_model'); } public function index() { $data['news'] = $this->news_model->get_news(); $data['title'] = 'News archive'; $this->load->view('templates/header', $data); $this->load->view('news/index', $data); $this->load->view('templates/footer'); } }

Important Note: Class names must start with an uppercase letter.

Passing URI segments to function function name

class News extends CI_Control CI_Controller ler { 

http://localhost/news_system/index.php/news/view/initializing-the-class http://localhost/news_system/index.php/news/view/ initializing-the-class

 public function function __construct() __construct() { 

parent::__construct();

CI allow to pass more than t han one segments  }  }

Class Constructors If you intend to use a constructor in Controllers, MUST MUST place  place parent::__construct(); Constructors are useful if you need to set some default values, or run a default process when your class is instantiated.

What is a Model? Models are PHP classes that are designed to work with information in your database. Basic prototype for News model class: class News_model extends CI_Model { public function __construct() {   $this->load->database(); } }

Class names must have the first letter capitalized

an t No te  ta mpor t  Im  I File name will be lower case version of class name i.e i .e news_model.php

Loading a Model $this->load->model('Model_name');

Use a Model $this->Model_name->method();

Active Record Class ➢

CodeIgniter uses a modified version of the Active Record Database Pattern.

➢

Pattern allows information to be retrieved retrieved,, inserted inserted,, and updated updated in  in your database with minimal scripting.

➢

A major benefit to using the Active Record features Record features is that it allows you to create database independent applications

Build SQL Select statement ➢

$query = $this->db->get $this->db->get('mytable'); ('mytable'); // Produces: SELECT * FROM mytable

➢

The second and third parameters enable you to set a limit and offset clause: $query = $this->db->get $this->db->get('mytable', ('mytable', 10, 20); // Produces: SELECT * FROM mytable LIMIT 20, 10

➢

$query = $this->db->get_where $this->db->get_where('mytable', ('mytable', array('id' => $id), $limit, $offset); // Produces: SELECT * FROM mytable where id=$id LIMIT $offset, $limit

➢

$this->db->select('title, $this->db->select ('title, content, date'); $query = $this->db->get('m $this->db->get('mytable'); ytable'); // Produces: SELECT title, content, date FROM mytable

Build SQL Select statement ➢

$this->db->select_max('age', $this->db->select_max ('age', 'member_age'); 'member_age'); $query = $this->db->get('members'); $this->db->get('members'); // Produces: SELECT MAX(age) as member_age FROM members

➢

$this->db->order_by('title $this->db->order_by ('title desc, name asc'); // Produces: ORDER BY title DESC, name ASC

➢

$names = array('Frank', 'Todd', 'James'); $this->db->where_in('username', $this->db->where_in ('username', $names); // Produces: WHERE username IN ('Frank', 'Todd', 'James')

Build SQL Insert statement ➢

$data = array( 'title' => 'My title' , 'name' => 'My Name' , 'date' => 'My date'); $this->db->insert('mytable', $this->db->insert ('mytable', $data); // Produces: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date')

➢

$this->db->set('name', $this->db->set ('name', $name); $this->db->insert('mytable'); // Produces: INSERT INTO mytable (name) VALUES ('{$name}') OR $array = array('name' => $name); $this->db->set($array); $this->db->insert('mytable'); //You can also pass an associative array to this function

Build SQL Update statement ➢

$data = array('title' => $title,'name' => $name,'date' => $date); $this->db->where('id', $this->db->where('id', $id); $this->db->update('mytable', $this->db->update ('mytable', $data); // Produces: // UPDATE mytable SET title = '{$title}', name = '{$name}', date = '{$date}' WHERE id = $id

➢

$data = array( array('title' => 'My 'My title','name' => => 'My Name 2' ,'date' => 'My date 2' ), array('title' => 'Another title' ,'name' => 'Another 'Another Name 2' ,'date' => 'Another date 2' ) ); $this->db->update_batch('mytable', $data, 'title'); $this->db->update_batch('mytable', // Produces: // UPDATE `mytable` SET `name` = CASE WHEN `title` = 'My titl e' THEN 'My Name 2' WHEN `title` = 'Another title' THEN 'Another Name 2' ELSE `name` END, `date` = CASE WHEN `title` = 'My title' THEN 'My date 2' WHEN `title` = 'Another title' THEN 'Another date 2' ELSE `date` END WHERE `title` IN ('My title','Another title')

Build SQL Delete statement ➢

$this->db->delete('mytable', $this->db->delete ('mytable', array('id' => $id)); // Produces: // DELETE FROM mytable WHERE id = $id

➢

$this->db->from('mytable'); $this->db->truncate(); $this->db->truncate (); // or

Note: If the TRUNCATE command isn't available, truncate() will execute as "DELETE FROM table".

$this->db->truncate('mytable'); $this->db->truncate ('mytable'); // Produce: // TRUNCATE mytable

What is View? ➢

A view is a web page, or a page fragment, like a header, footer, sidebar, etc.

➢

Views are never called directly, they must be loaded by a controller

My Blog

Loading a View $this->load->view('name');

Welcome to my Blog!

Helper ➢

Helpers means “help you with tasks”.

➢

Each helper file is simply a collection of functions or methods.

➢

Stored in your system/helpers, system/helpers, or application/helpers directory

Few common Helpers are listed below: ➢

URL Helpers, Helpers, that assist in creating links

➢

Form Helpers that Helpers that help you create form elements

➢

Text Helpers perform Helpers perform various text formatting routines

➢

Cookie Helpers set Helpers set and read cookies

➢

File Helpers help Helpers  help you deal with files

Loading a Helper $this->load->helper('name');

[ GlobAl CodESTER

]

Template Integration

Where we put css/js/image css/js/image directory  directory ? ➢

Local CI Directory “news_system”

➢

Configure “base_url“ “base_url“ &  & define one more variable “BASE_URI” To do this, open up system/application/config/config.php

➢

Directory structure of project “news_system”

Create templates directory ➢

Create a “templates” “templates” directory  directory To do this, open up application/views/

➢

Create “header.php” “header.php” &  & “footer.php” files in “templates” directory

Link to css/js/images ➢

For “css” “css” directory  directory