preg_match and that stuff..

Tanax · 12-21-2007, 04:49 PM

Hey!

I don't know barely anything about this, and I want to create a simple template system where I would replace variables.

What I would want is like this:

HTML Code:

Hello and welcome {user.username}!
Your last visit was {user.lastvisit} here on {site.name}!

The "username" is the key in the "user" array.
So

HTML Code:

{user.lastvisit}

would fetch

PHP Code:


			
$user['lastvisit']

PHP Code:


			
$user = array();

$user['lastvisit'] = 'something';

$user['username'] = 'Tanax';



$site = array();

$site['name'] = 'TalkPHP';



$values = array();

$values[] = $user;

$values[] = $site;



$tpl->parse('index', $values);

How would the function parse look like??

sjaq · 12-21-2007, 06:47 PM

I tried it a couple of different ways but this seems to work fine:
Template.php

PHP Code:


			
<?php 

    class Template
    {
        public $data;
        const TEMPLATE_PATH = './';
        
        public function parse($template, array $values)
        {
            $this->data = $values;
            if(!file_exists(self::TEMPLATE_PATH . $template . '.php')) {
                die('Template file doesn\'t exist');
            } else {
                $fb = fopen(self::TEMPLATE_PATH . $template . '.php', 'r');
                $contents = fread($fb, filesize(self::TEMPLATE_PATH . $template . '.php'));
                fclose($fb);
                
                $replaced = preg_replace_callback('/\{([a-z0-9\.]+)\}/i', array($this, 'replace_callback'), $contents);
                
                print $replaced;
            }
        }
        
        private function replace_callback($matches) 
        {
            $depth = explode('.', $matches[1]);
            $out = $this->data;
            
            if(count($depth) > 1) {
                foreach($depth as $ar) {
                    $out = $out[$ar];
                }
            } else {
                $out = $out[$depth[0]];
            }
            
            return $out;
        }
    }

?>

Test.php (the template)

Code:

Hello and welcome {user.username}!
Your last visit was {user.lastvisit} here on {site.name}!
Your postcount is: {user.posts.count}!

index.php

PHP Code:


			
<?php 

    require './template.php';
    
    $tpl = new Template;
    
    $tpl->parse('test', array(
        'user' => array(
            'lastvisit' => 'yesterday',
            'username' => 'Sjaq',
            'posts' => array('count' => 10)
        ),
        'site' => array(
            'name' => 'TalkPHP'
        )
    ));

?>

(My indentation style is a bit inconsistent, I'm trying to adapt the BSD/Allman style)

Tanax · 12-21-2007, 07:13 PM

Quote:

Originally Posted by sjaq

I tried it a couple of different ways but this seems to work fine:
Template.php

PHP Code:


			
<?php 



    class Template

    {

        public $data;

        const TEMPLATE_PATH = './';

        

        public function parse($template, array $values)

        {

            $this->data = $values;

            if(!file_exists(self::TEMPLATE_PATH . $template . '.php')) {

                die('Template file doesn\'t exist');

            } else {

                $fb = fopen(self::TEMPLATE_PATH . $template . '.php', 'r');

                $contents = fread($fb, filesize(self::TEMPLATE_PATH . $template . '.php'));

                fclose($fb);

                

                $replaced = preg_replace_callback('/\{([a-z0-9\.]+)\}/i', array($this, 'replace_callback'), $contents);

                

                print $replaced;

            }

        }

        

        private function replace_callback($matches) 

        {

            $depth = explode('.', $matches[1]);

            $out = $this->data;

            

            if(count($depth) > 1) {

                foreach($depth as $ar) {

                    $out = $out[$ar];

                }

            } else {

                $out = $out[$depth[0]];

            }

            

            return $out;

        }

    }



?>

Test.php (the template)

Code:

Hello and welcome {user.username}!
Your last visit was {user.lastvisit} here on {site.name}!
Your postcount is: {user.posts.count}!

index.php

PHP Code:


			
<?php 



    require './template.php';

    

    $tpl = new Template;

    

    $tpl->parse('test', array(

        'user' => array(

            'lastvisit' => 'yesterday',

            'username' => 'Sjaq',

            'posts' => array('count' => 10)

        ),

        'site' => array(

            'name' => 'TalkPHP'

        )

    ));



?>

(My indentation style is a bit inconsistent, I'm trying to adapt the BSD/Allman style)

Wow, thanks!! I will study the code more carefully :D

Also one thing, does this also work with variables?
Like if I do:

Code:

You are currently on page {page}

And that would be replaced with the value of

PHP Code:


			
$page

???

THanks once again :)

sjaq · 12-21-2007, 07:18 PM

Quote:

Originally Posted by Tanax

Wow, thanks!! I will study the code more carefully :D

Also one thing, does this also work with variables?
Like if I do:

Code:

You are currently on page {page}

And that would be replaced with the value of

PHP Code:


			
$page

???

THanks once again :)

No, it won't.

It gets all the data out of the array so if you would like to replace {page} with the contents of $page you'll have to do something like this:

PHP Code:


			
<?php 



    $values = array(

        'page' => $page

    );



    $tpl->parse('test', $values);



?>

Tanax · 12-21-2007, 09:07 PM

Quote:

Originally Posted by sjaq

No, it won't.

It gets all the data out of the array so if you would like to replace {page} with the contents of $page you'll have to do something like this:

PHP Code:


			
<?php 

    $values = array(
        'page' => $page
    );

    $tpl->parse('test', $values);

?>

Thanks! THat worked :D
Oh this is awesome ;)

Thanks a bunch!

Edit:
Can you explain this line?

PHP Code:


			
$replaced = preg_replace_callback('/\{([a-z0-9\.]+)\}/i', array($this, 'replace_callback'), $contents);

???

sjaq · 12-21-2007, 09:46 PM

Quote:

Originally Posted by Tanax

Can you explain this line?

PHP Code:


			
$replaced = preg_replace_callback('/\{([a-z0-9\.]+)\}/i', array($this, 'replace_callback'), $contents);

???

I'm assuming you understand regular expressions and I don't have to explain that part..

What that line does is that it searches for all occurrences of {([a-z0-9\.]+)} within the template file (which contents are in $contents) and then parses the matched string to $this->replace_callback.

Then the replace_callback method gets a string eg. "user.posts.count". It then "explodes" that string by each occurrence of "." so we get an array which looks something like this:

PHP Code:


			
Array

(

    [0] => user

    [1] => posts

    [2] => count

)

And then it selects the correct data from the array(the second argument of the parse method) and returns it to the preg_replace_callback method, which in turn replaces the matched string by the returned data in the $contents string.

I recommend that you read the php site..