CodeIgniter 3 Tutorial 1: Download, Installation, Introduction and Welcome!

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This is the first part of CodeIgniter 3 tutorials. CodeIgniter 3.0 introduced a lot of upgrades over 2.x versions of CodeIgniter. Users who wish to upgrade to CodeIgniter 3 may have to perform changes as mentioned here in the official CodeIgniter 3.0 documentation.

Here are my Tutorials for CodeIgniter:

CodeIgniter 3 Tutorials
CodeIgniter 2.2 Tutorials

This tutorial series is for new users of CodeIgniter users who wish to start with CodeIgniter 3.x. We will start with downloading Codeigniter.

CodeIgniter can be obtained from any of the two places.

  1. Official Website Here
  2. Official Github Repository Here

Lets download from the official website

Now, install XAMPP as I have explained here and also here for my CodeIgniter 2.2 Tutorials Series.

Now, once you have installed XAMPP and downloaded CodeIgniter 3, we can now start installing CodeIgniter. Follow the following steps.

  1. Assuming you installed XAMPP in D:\, go to D:\xampp\htdocs
  2. For this example, create a subfolder “tutorial” so we now have,
  3. Now, extract the contents of downloaded CodeIgniter files here.
  4. You will now have the following base structure of CodeIgniter.
  5. CodeIgniter is INSTALLED!
  6. Here is the simple explanation of all of these files and folders (You can skip if you are already familiar otehrwise, I highly recommend reading the brief descriptions below):
    1. \application\
      (108Kb, 45 Files)
      This folder contains the web application that you will develop using CodeIgniter.
    2. \system\
      (2.05MB, 202 Files)
      This folder contains the actual CodeIgniter framework. In other words, the cool stuff! It is not necessary, but it would be nice to open this folder by yourself and see how everything works behind the scenes. Also, this is the folder that is affected with each version. So yuou might be required to make changes to this folder if you ever wish to upgrade.
    3. \user_guide\
      (6.41MB, 191 Files)
      This folder contains the latest CodeIgniter documentation at the time of release of whichever version that you downloaded. It is SAFE TO DELETE this folder at the cost of losing offline official guide. I personally delete these from my projects to save size.
    4. \.gitignore
      This file tells Github to ignore the specified files and folders to be ignored when committing to a repository.
    5. \composer.json
      This file is used with composer to keep the packages up to date.
    6. \
      Simply put, this is a readme file for “contributing to the CodeIgniter project” topic.
    7. \index.php
      This file contains variables that control how your application behaves. For example,

      1. Error Reporting levels
      2. \system\ folder name (which it allows to be changed)
      3. Want to know how to change \application\ folder name? This file does it!
      4. Want to move the \application\view\ folder out of the \application\ folder? index.php does it!
      5. Override application routing.
      6. Meddle with the config parameters.


And some more parameters which should not be touched and if you did, then God help you.


    • \license.txt
      Legal stuff about CodeIgniter Project
    • \readme.rst
      Official Readme of the CodeIgniter project!
    • You will see the following default welcome screen:

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