CodeIgniter:
Introduction to CodeIgniter Framework
CodeIgniter Step By Step Tutorial: CodeIgniter (CI) is one of popular php framework. If you are already building PHP Application, CodeIgniter will help you to do it better and more easily. With CodeIgniter, you can save time, make your web more robust, your code will be easier to read and maintenance. It is free, lightweight, and simple to install. In this post, we will know more deep about CodeIgniter before write code.
Nice, CodeIgniter is small and lightweight framework. The
zipped download for version 1.5 is only 737 KB. You don't need long time to
download it. You can get it from http://www.codeigniter.com. CI was written by
Rick Ellis, rock musician turned programmer.
With CodeIgniter, you can cut down the amount of code you
need to type. This is not just good for lazy, but: less type, fewer mistake,
and less time for spend debugging.
But, CodeIgniter is not everything. We will not find 'engine
generator' that can build page self. Several frameworks have features like
that. For example, they can create web page (that to do basic Create, Read,
Update, and Delete operation) automatically. CodeIgniter doesn't do this.
This, I copy from their help page: "Our goal for
CodeIgniter is maximum performance, capability, and flexibility in the
smallest, lightest possible package.
...
From a technical and architectural standpoint, CodeIgniter
was created with the following objectives:
• Dynamic
Instantiation. In CodeIgniter, components are loaded and routines executed only
when requested, rather than globally. No assumptions are made by the system
regarding what may be needed beyond the minimal core resources, so the system
is very light-weight by default. The events, as triggered by the HTTP request,
and the controllers and views you design will determine what is invoked.
• Loose
Coupling. Coupling is the degree to which components of a system rely on each
other. The less components depend on each other the more reusable and flexible
the system becomes. Our goal was a very loosely coupled system.
• Component
Singularity. Singularity is the degree to which components have a narrowly
focused purpose. In CodeIgniter, each class and its functions are highly
autonomous in order to allow maximum usefulness.
..."
Nice feature, CodeIgniter is very flexible. We can apply at
PHP 4.3.2 and above, or PHP 5. It will realy help us when our web hosting still
don't support PHP 5. CI support serveral database: MySQL, MySQLi, MS SQL,
Postgre, Oracle, SQLite, and ODBC.
CodeIgniter:
Installation
CodeIgniter Step By Step Tutorial: After understand about
codeIgniter at this, now, we learn how to install CodeIgniter. We will install
to our local computer. Before follow this instruction, please download
CodeIgniter at www.codeigniter.com.
1. Open your
root web server.
2. Put
CodeIgniter downloaded.
3. Extract
it, you will get a folder named "codeigniter_[version]".
4. For
simple, rename the folder to be "CodeIgniter" only.
5. Now, open
config.php within CodeIgniter\system\application\config.
6. Change
base site url at line 14:
7. Point
your browser to http://localhost/CodeIgniter.
You should get like this:
CodeIgniter:
Creating First Application at CodeIgniter
CodeIgniter Step By Step Tutorial: As usually, we will
create first application by build hello application. But, before write code, we
must know that we will build application use Model Controller View (MVC)
pattern. We ever talk about MVC at here. Hope you read that posting if you
still don't know about MVC. Although that post about Joomla, it doesn't matter.
It is same.
1. First, we make controller, create a file name
"hello.php" within: \system\application\controllers. Enter following
code:
2. Next step, make a view. Create you_view.php
within CodeIgniter\system\application\views. Enter just simple line code like:
3. Now,
test your application. Point your browser to
http://localhost/CodeIgniter/index.php/Hello/you You should get like this:
See, this flow:
CodeIgniter: Creating and Sending
Parameters between Controller and View
CodeIgniter Step By Step Tutorial: We still wok with our
first application at CodeIgniter. But we will build controller and view better.
Create parameters in controller and send it to view. It will make our
application more flexible.
Open your hello.php within
CodeIgniter/system/application/controller. Overwrite become like this:
Now, open your you_view.php within
CodeIgniter/system/application/views. Rewrite with following code:
Point your browser to http://localhost/CodeIgniter/index.php/hello/you.
CodeIgniter: Getting Parameters from GET
CodeIgniter Step By Step Tutorial: If previous post we learn
how to send parameter to view, now, we will learn how to get parameter from
GET. As we know, we can see this parameter from Url. Example:
http://localhost/index.php?name=Andi. Clear, we can get parameter name. How
about in CodeIgniter?
Ok, we learn by doing. Open again your hello.php within
CodeIgniter/system/application/controller. Rewrite with following code:
Now, try pointing your browser to http://localhost/CodeIgniter/index.php/hello/you/Imanda/Fa
This is analysis:
CodeIgniter: Setting Database Configuration
CodeIgniter Step By Step Tutorial: Previous post, we have build
simple first application. That application do not use database. In this post,
we try to set database for CodeIgniter.
Please, open database.php within
CodeIgniter\system\application\config. Set config like below:
Make sure, it matches with your database.
CodeIgniter:
Preparing Database
CodeIgniter Step By Step Tutorial: After set database
configuration,we will learn about showing data from database in CodeIgniter.
But, before that, we prepare a database for practice. This post creates a
database named "codeigniter" and a table named "hello". We
use phpMyAdmin for easy.
1. Open your
phpmyadmin.
2. Enter
database name "codeigniter" in create new database field.
3. Click
Create button. Your database will be created.
4. Create
new table by entering name of new table at create new table field.
5. Enter
number of fields.
6. Click Go
button.
7. Enter
name of field, type, and length
8. Choose
auto increment and check primary key for primary key field.
9. Click
Save button.
10. Now, we
insert data. Click [Insert tab].
11. Enter
data.
12. Click Go
for saving.
CodeIgniter: Showing Simple All Data
CodeIgniter Step By Step Tutorial: We have set database and
create table for CodeIgniter practice. Now, we learn how to show data in
CodeIgniter. As we know, CodeIgniter use MVC pattern. We will use Model for
retrieve data from database.
First, build a model. Create a file named
"employee_model.php" within CodeIgniter/CodeIgniter\system\application\models.
Enter following code:
Next, we make a view. Create a file named
"employee_viewall.php" within CodeIgniter\system\application\views.
Enter folowing code:
Build controller. Create a file named
"employee.php" within CodeIgniter\system\application\controllers.
Enter following code:
Now, try to point your browser to http://localhost/CodeIgniter/index.php/employee/getall
CodeIgniter: Showing Simple One Data
CodeIgniter Step By Step Tutorial: After show all data, We
learn how to show one data. We want a data with certain ID, example ID = 1. We
still use same files with previous practice.
For model: Open "employee_model.php" within
CodeIgniter\system\application\models. Add following function:
For Controller: Open "employee.php" within
CodeIgniter\system\application\controllers. Add following function:
For View: Open "employee_view.php" within
CodeIgniter\system\application\views. Enter following code:
Now, test it. Point your browser to http://localhost/CodeIgniter/index.php/employee/get.
CodeIgniter: Choosing a Data from GET
CodeIgniter Step By Step Tutorial: At previous tutorial, we
learn show a data. But we have defined ID that we want to show. In this post,
we learn how to show a data that ID defined from GET.
For model: Open "employee_model.php" within
CodeIgniter\system\application\models. Add following function:
For Controller: Open "employee.php" within
CodeIgniter\system\application\controllers. Add following function:
Now, test it. Point your browser to http://localhost/CodeIgniter/index.php/employee/get/2.
