By means of a simple and well-designed toolkit, Code igniter is a commanding PHP framework. If we consider web applications with advanced features, then to create such an application Code igniter is one of the efficient PHP Frameworks. As it makes web application always ready, learning becomes easier. Also due to the usual PHP coding it makes the code portable and only because of this, Compared to other frameworks, Code Igniter is significantly simple and fast.

Derived from the Model-View-Controller (MVC) development pattern, it is a software approach to unscramble application logic and presentation by alienating from PHP scripting. But in reality, web pages containing minimal scripting are allowable by code igniter.

MVC structure of Code igniter:

Model: Basically data is represented by model and all its functions retrieve, insert and restructure the database information as model contains data logic and also represents classes, data structures etc.

Despite the fact of data validation, validation class validates the data by defining the validating object with a few assigned rules and certain error messages that have been programmed. In case of data sent by URL, automatic validation procedure has been provided by validation object.

View: is the information- in general a web page which is accessible to users. Just like a header or footer, we can say a page scrap in Code Igniter, which can either be RSS page or any page.

Controller: is just a name of a class file linked with a URI and it is loaded by Code Igniter. But, for loading purpose not only matching of controller’s name with first segment of Url is necessary, but also first character of class name is required in upper case. Here, the parent controller class is extended and all its functions are inherited by controller class. Function of controller, need to call is determined by second segment of the URL as it loads “index” function when clears.

For example:

<?php
Class ABC extends XY_Controller {

        Public function index ()
        {
                Echo ‘Hello World!’;
        }

        public function wishes ()
        {
                echo ‘Good Morning!’;
        }
}
?>

Now, it displays “Good Morning!” after loading example.com/index.php/abc/wishes/

When either a URL is absent or just a site root URL is requested, in that case loading of Default Controller is required. Thus, effectively, Controller serves as a mediator between the Model, the View, and any other resources essential for processing the HTTP request and generating a web page.

Remapping Function Calls:

Using function remap ( ), Code Igniter overrides activity of determining controller’s calling function by second segment of the URL. A function named as remap (), is always called apart from the URL if enclosed in controller. Code igniter remaps each URL, through the URL routing feature.

Application flow of Code Igniter as follows:

Front controller initializes base resources which are mandatory to run CodeIgniter and router examines and resolves the HTTP request. Here, an existing cache file can be sent directly to the browser. Hence in security view, prior to loading of an application controller, filtering of HTTP request and user data is necessary. Model, core libraries, helpers, and any other resources, vital in processing the specific request, are loaded by Controller and final interpretation makes finalized View visible to the web browser.

But, if maintenance of model can be done inspite of additional separation and still intricacy is rising, in such a case Code Igniter has a quite loose approach to MVC pattern. Due to this reason, to build an application, just controllers and Views can be used by completely ignoring the model part itself. Also integration of own existing scripts and development of core libraries for the system can be enabled via Code Igniter only.

In short, when a framework with a small track, minimal design, outstanding performance, comprehensible documentation, variety of PHP versions and configurations is required, in such situations Code igniter is the best option as in such a framework, use of command line and specific coding rules is not restricted.

Thus, CodeIgniter Framework helps to develop rapidly, its own application which is very simple to handle and stout in functioning.

Advantages:

1. Easy and hassle-free migration from server hosting to dedicated server hosting.
2. Easy to learn, adopt and deploy
3. Easy handling and customizing.
4. A new functionality has been applied without affecting the customization at all.
5. Offers flexibility and easy management With MVC based framework.
6. Active Record Implementation is simply superb and easy to remember.
7. Provides easier configuration and customization of configuration files.
8. Facilitates easy working with a variety of developers.
9. Good collection of possessed libraries.
10. Awesome documentation of the user guide, which makes it easy for any coder to use the whole framework.
11. Enables to incorporate its own existing scripts as well as develop core libraries for the system,
12. Lightweight and extensive Thai user base

Disadvantages:

1. Its PHP based only and not very object-oriented in some parts
2. PHP4 legacy code,
3. Company-driven instead of community-driven,
4. Irregular releases,
5. Framework itself has no built-in ORM (only via 3rd party solutions).

Benefits of Code Igniter:

1. A small track and astounding presentation
2. Provision of broad compatibility along with standard hosting accounts,
3. Configuration and normal coding rules are not required
4. Depiction of straightforward solutions
5. Free from complex structures and development