====== Controllers ======

**What Are They?**
Controllers take care of event handle, make queries to Models and finally  pass data to Views.

**Basic Usage**
Let's say you want to make a page about yourself. We are going to create a new controller just for that. Create a new PHP file at application/controllers/about.php. This file will be our new controller.

When the web browser requests the page /about (remember inside route array set an element 'about' => 'about.index'),  Salem will load the about.php controller and run the index() function. If the controller or the function is missing then It will display a 404 error page (not found error).

Now in our new controller create the controller class and the index() function.
<code php| about.php>
<?php
namespace Controller; //Never forget
use Salem\load, Salem\db, Salem\View, Salem\input, Salem\Validate, Salem\Url; //only if you will use some of this core Salem libraries

class About {

	public function index() {
		echo "This is a page about myself !";	
	}
}
?>
</code>

Now if you visit /about in your web browser you should see "This is a page about myself !".

**Arguments**
URLs can be infinitely long. What that means is that after the controller and function portions on the URL all other portions are just arguments for the controller function. Create a function youSaid() inside about class and remember inside route array set an element 'about/you/:words' => 'about.youSaid') so it looks like this:

<code php| about.php>
<?php
namespace Controller; //Never forget
use Salem\load, Salem\db, Salem\View, Salem\input, Salem\Validate, Salem\Url; //only if you will use some of this core Salem libraries

class About {

	public function index() {
		echo "This is a page about myself !";	
	}
        
        public function youSaid($message)
        {
                echo "You said: ".$message;
        }
}
</code>
Now if you visit /about/you/cool it will display "You said: cool".

Now there is one problem with this. If you where to visit /about/you then you would get a 404 error! This is because you can't just run youSaid(), it has a required argument! If you want people to still be able to visit the page, then you need to make your argument optional:
<code php>
public function youSaid($message = 'nothing at all')
{
  echo "You said: ".$message;
}
</code>
Now visiting /about/you will produce "You said: nothing at all", althoughthis if you visiting /about/you/cool will still display"You said: cool".

At this point you should try experimenting around with adding additional controllers, functions, and arguments and see what happens.

**Parent Controllers**
In Salem is possible to make controller classes extend from other controller classes. For example if you want to extend your about.php controller:

<code php| extabout.php>
<?php
namespace Controller;
use Salem\load;//In this case I use the Load library

load::parentController('about');

class ExtAbout extends About{
  function index(){
    $this->youSaid("I'm cool!");
  }
}
?>
</code>
----
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