Codeigniter - Model-View-Controller

CodeIgniter is based on the Model-View-Controller development pattern. MVC is a software approach that separates application logic from presentation. In practice, it permits your web pages to contain minimal scripting since the presentation is separate from the PHP scripting.

• The Model represents your data structures. Typically your model classes will contain functions that help you retrieve, insert, and update information in your database.
• The View is the information that is being presented to a user. A View will normally be a web page, but in CodeIgniter, a view can also be a page fragment like a header or footer. It can also be an RSS page, or any other type of "page".
• The Controller serves as an intermediary between the Model, the View, and any other resources needed to process the HTTP request and generate a web page.

CodeIgniter has a fairly loose approach to MVC since Models are not required. If you don't need the added separation, or find that maintaining models requires more complexity than you want, you can ignore them and build your application minimally using Controllers and Views. CodeIgniter also enables you to incorporate your own existing scripts, or even develop core libraries for the system, enabling you to work in a way that makes the most sense to you.

Codeigniter Installation Instructions

CodeIgniter is installed in four steps:

1. Unzip the package. (http://codeigniter.com/downloads/)
2. Upload the CodeIgniter folders and files to your server. Normally the index.php file will be at your root.
3. Open the application/config/config.php file with a text editor and set your base URL. If you intend to use encryption or sessions, set your encryption key.
4. If you intend to use a database, open the application/config/database.php file with a text editor and set your database settings.

If you wish to increase security by hiding the location of your CodeIgniter files you can rename the system and application folders to something more private. If you do rename them, you must open your main index.php file and set the $system_folder and $application_folder variables at the top of the file with the new name you've chosen.
For the best security, both the system and any application folders should be placed above web root so that they are not directly accessible via a browser. By default, .htaccess files are included in each folder to help prevent direct access, but it is best to remove them from public access entirely in case the web server configuration changes or doesn't abide by the .htaccess.
After moving them, open your main index.php file and set the $system_folder and $application_folder variables, preferably with a full path, e.g. '/www/MyUser/system'.
One additional measure to take in production environments is to disable PHP error reporting and any other development-only functionality. In CodeIgniter, this can be done by setting the ENVIRONMENT constant, which is more fully described on the security page.
That's it!

Getting started CodeIgniter

CodeIgniter is an Application Development Framework - a toolkit - for people who build web sites using PHP. Its goal is to enable you to develop projects much faster than you could if you were writing code from scratch, by providing a rich set of libraries for commonly needed tasks, as well as a simple interface and logical structure to access these libraries. CodeIgniter lets you creatively focus on your project by minimizing the amount of code needed for a given task.

CodeIgniter is right for you if:

• You want a framework with a small footprint.
• You need exceptional performance.
• You need broad compatibility with standard hosting accounts that run a variety of PHP versions and configurations.
• You want a framework that requires nearly zero configuration.
• You want a framework that does not require you to use the command line.
• You want a framework that does not require you to adhere to restrictive coding rules.
• You do not want to be forced to learn a templating language (although a template parser is optionally available if you desire one).
• You eschew complexity, favoring simple solutions.
• You need clear, thorough documentation.

Can't start portgresql in F15, F16

First please login as follows in your terminal :

# su - postgres

Then type

$ pg_ctl init

---------------------------------

After execute above command try to start the server as normal way :

systemctl start postgresql.service or /etc/init.d/postgresql start

If you want to start the server from start-up please type as following in your terminal:

chkconfig postgresql on