How to implement hook_theme in drupal 7?

solomon_wzs picture solomon_wzs · Oct 20, 2012 · Viewed 15.7k times · Source

I created a new drupal 7 theme and trying to implement hook_theme at template.php like this:

function mytheme_theme($existing, $type, $theme, $path){
    return array(
        'mytheme_header'=>array(
            'template'=>'header',
            'path'=>$path.'/templates',
            'type'=>'theme',
        ),
    );
}

then I placed header.tpl.php into templates directory and cleared all caches, and call theme function:

theme('mytheme_header', $vars);

and header.tpl.php likes this:

<?php
fb('calling header template');//the function of FirePHP to output debug info
print '<div>Header</div>';
//...

I check Firebug and it get the info 'calling header template', it mean it had called header.tpl.php, but it didn't print the html code. What's wrong with my code?

Answer

Muhammad Reda picture Muhammad Reda · Oct 20, 2012

Try to add the variables array in hook_theme

function mytheme_theme($existing, $type, $theme, $path){
    return array(
        'mytheme_header' => array(
            'template' => 'header',
            'path' => $path . '/templates',
            'type' => 'theme',
            'variables' => array(
                'title' => NULL,
                'some_text' => NULL,
            ),
        ),
    );
}

In your header.tpl.php file:

<h1><?php print $title; ?></h1>
<p><?php print $some_text; ?></p>

Then, print it out like this:

$vars = array();
$vars['title'] = "This is a title";
$vars['some_text'] = "Some text...";
print theme('mytheme_header', $vars);