Professional CodeIgniter

Chapter 3: A 10,000 - Foot View of CodeIgniter

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//$username and $password are passed in from another process

//most likely a login form and then cleansed

$this- > db- > select(‘email’);

$this- > db- > from(‘users’);

$this- > db- > where(‘username’, $username);

$this- > db- > where(‘password’, $password);

$this- > db- > where(‘status’, ‘live’);

$this- > db- > limit(1);

$Q = $this- > db- > get();

if ($Q- > num_rows() == 1){

$row = $Q- > row();

$this- > session- > set_userdata(‘user_email’], $row- > email);

}

It would then be very simple to retrieve that e - mail if you ever wanted to print it in a view.

< ?php

echo $this- > session- > userdata(‘email’);

? >

Because CodeIgniter sessions are saved in a client - side cookie, many developers don ’ t trust them for

storage of sensitive information. Even with a 32 - character salt for encryption, it ’ s still possible that

somebody might tamper with these data. In this book, you use encryption on sessions but restrict its

usage to unimportant information. For the more sensitive things, like checking for a user login, you

should use PHP sessions.

CodeIgniter Helpers

Helpers , as their name implies, help you with specific tasks. Unlike libraries, helpers are not object -

oriented but procedural in nature. Each helper contains one or more functions, each focusing on a

specific task, with zero dependence on other functions.

Helpers can either be loaded locally or autoloaded in /system/application/config/autoload.php.

CodeIgniter ships with the following built - in helpers:

Array — The Array helper contains functions that help you work with arrays. For example, the

random_element() function takes an array as input and returns a random element from it.

Cookie — The Cookie helper contains functions that help you set, read, and delete cookie data.

Date — The Date helper contains functions that help you work with dates. For example, the

now() function returns the current time as a UNIX time stamp.

Directory — The Directory helper contains a single function that helps you work with directories.

For example, the directory_map function reads a specified directory path and builds an array

of it that contains all of its files and subdirectories.

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