Authentication is the process of confirming that a person is who they say they are. In software the most common method of authentication is the use of a password that only the person knows.

Zend_Auth

Zend framework provides Zend_Auth as an interface to authenticate a user against different back-ends (Database, LDAP, etc…). Since all adapters that use Zend_Auth share the same interface you can use any of them with almost no changes in the code.

Authentication is sometimes confused with authorization (the process of verifying if a person has access to a resource), and although they do different things they are related because you have to know the identity of the user before you can check if they have permission to a resource.

Static analysis is the practice of analyzing code without actually executing it. The analysis can do a wide variety of checks with different tools. I will focus my attention on the most common tools available for PHP code analysis.

For installing some of the tools in this article you will need to have these packages installed on your system:

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sudo apt-get install php-pear
sudo apt-get install php5-xsl
sudo apt-get install php5-dev
sudo apt-get install default-jdk
sudo apt-get install ant

PHP Code Sniffer

PHP Code Sniffer is a tool that helps us make sure our coding style standards are being followed. To install you just need to:

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sudo pear install PHP_CodeSniffer

In my journey to learn python, the next step is to learn Django. Django is a web framework powered by python, so to use it we need to make sure we have python installed:

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adrian@my-xubuntu:~$ python -V
Python 2.7.3

Now we can go ahead and install the Django package

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sudo apt-get install python-django

That installation makes Django automatically available to python, so you can do something like this:

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adrian@my-xubuntu:~$ python
Python 2.7.3 (default, Sep 26 2012, 21:51:14)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> django.VERSION
(1, 4, 1, 'final', 0)

Xdebug is a great tool for debugging our PHP code, but another thing it does very well is help us find bottlenecks in our applications. For instructions on installing xDebug you can see my article Debugging PHP code with xDebug.

Enabling the profiler

We can tell xDebug to profile our code by adding this in our php.ini file:

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xdebug.profiler_enable = 1
xdebug.profiler_output_dir = '/path/to/folder/'

xdebug.profiler_output_dir is the folder where xDebug will dump the profile information. Make sure this folder is writable by apache or you won’t see any file generated in that folder.

When you get this error the only thing you need to do is add a line similar to this one to your php.ini file:

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date.timezone = "America/Mexico_City"

You can get a list of the supported timezones on this URL: http://php.net/manual/en/timezones.php. The error should go away after you restart apache.

For Linux systems there are some times two php.ini files, one for apache and one for CLI. Make sure you add the line to both files.

JavaScript Object Orientation is very different from most other popular languages (C++, Java, PHP), so if you come from one of those languages it becomes a little hard to wrap your mind on how things work in JS.

Prototypal inheritance is one of those things where people have trouble when they arrive to JS. Let’s see it in action:

When working with floating elements there is one problem web developers usually face. Since float elements are removed from the normal flow of the page, this causes some other side effects that may be seen as undesireable.

Lets begin with this HTML structure:

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<ul>
    <li>One</li>
    <li>Two</li>
</ul>

To be able to successsfully work with the DOM, first we need to understand what it is. DOM stands for Document Object Model and it is the way browsers represent the structure of your HTML (XHTML or XML) document so JS can navigate it (actually it is supposed to be language agnostic, but I’ll explain how to interact with it using JS), or modify it.

The way you can access the DOM in a typical browser is by refering to the window variable. The window variable gives you access to attributes like history, location and document. In this articule I will focus on window.document.

This is a very special scenario and you may never want to really do this, but I found myself in the necessity of changing the visibility of an object’s methods an attributes at runtime so I could access them directly.

To do this I had to use reflection and magic methods in a magic way. Since we can’t just plug methods to an object in PHP, I had to create a class with already defined magic methods that would allow me to access the protected and private members of an object using reflection.

This is the class I created with an explanation of what it does:

Xdebug is a PHP extension which provides debugging, tracing and profiling capabilities.

Installing xDebug in an Ubuntu based distribution is very easy using apt-get:

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sudo apt-get install php5-xdebug

Just by installing xDebug you will get two very basic but useful rewards: Pretty var_dumps and pretty error messages.