Ultra-small template inheritance in PHP

Readme.md

Template Inheritance

view([filename], array $data);

Then inside [filename] you have helper functions $block(key, [default]), $start(key), and $end(). In addition, you can include a parent view using $extends = [parentview];.

Values and blocks from a child view will overwrite the values defined in a parent view (or grandparent view, etc..) allowing you to safely inherit things like a page title from multiple nested children. Suppose you view('post') and it inherited from post which in turn inherited from layout:

Layout: <?= $block('page_title', 'Welcome!'); ?>
	Page.php: <?php $page_title = 'Article Title'; ?>
		Post.php <?php $page_title = $post->title; ?>

The result would be $post->title and not "Article Title" or "Welcome!" dispite the fact they were defined in the parent views.

one.php

<?php $start('nav'); ?>
ONE-NAV
<?php $end(); ?>

<?php $one = 'one'; ?>
<?php $shared = 'one'; ?>

One Content

<?php $extends = 'two'; ?>

sample_output.txt

// view('one') renders:

ONE-NAV

1. one 
2. two 
3. one 

Three Content

three.php

<?= $block('nav', 'THREE-NAV'); ?>

1. <?= $block('one'); ?> 
2. <?= $block('two'); ?> 
3. <?= $block('shared'); ?> 

Three Content

two.php

<?php $start('nav'); ?>
TWO-NAV
<?php $end(); ?>

<?php $one = 'two'; ?>
<?php $two = 'two'; ?>
<?php $shared = 'two'; ?>

Two Content

<?php $extends = 'three'; ?>

view.php

<?php

/**
 * This looks like a mess, and it is, but it's a powerful mess.
 * Auto-scoped $block('name') and template inheritance.
 *
 * "foo.php" child view:
 *
 * 		<?php $title = 'SEO Title'; ?>
 * 		<?php $nav = view('nav', array('links'=> $links_array))); ?>
 * 		This is the content of foo.php
 * 		<?php $extends = 'layout'; ?>
 * 
 * "nav.php" view:
 *
 * 		<ul>
 * 		<?php foreach($links as $a => $link): ?>
 * 			<li><a href="<?= $a; ?>"><?= $link; ?></a></li>
 * 		<?php endif; ?>
 * 		</ul>
 *
 * Then inside 'layout.php':
 *
 * 		<?= $block('nav', '<ul>...</ul>'); ?>
 * 		<h1><?= $block('title', 'Hello World'); ?></h1>
 * 		<?= $block('content'); ?>
 * 		&copy; 2014 Company
 */
function view($file, $data = array())
{
	$__scope = $data;
	unset($data);
	$extends = $file;
	while(isset($extends)) {
		$__file = $extends;
		unset($extends, $content);

		$__v = $__scope = $__scope + array_diff_key(get_defined_vars(), array('__file'=>0, '__scope'=>0));
 
		$start = function($name) use(&$__v) {
			ob_start(function($buffer) use(&$name, &$__v) {
				if(empty($__v[$name])) {
					$__v[$name] = $buffer;
				}
				return $__v[$name];
			});
		};
 
		$end = function() {
			ob_end_flush();
		};
		
		$block = function($key, $default = null) use(&$__v) {
			return isset($__v[$key]) ? $__v[$key] : $default;
		};
 
		ob_start();
		require("theme/$__file.php");

		$content = trim(ob_get_contents());
		extract($__v, EXTR_SKIP);

		// $content is a funny variable (keep the original unless this is the last parent)
		if(isset($__v['content'])) {
			if(empty($__scope['content'])) {
				$__scope['content'] = $__v['content'];
			}
		}

		unset($__v, $__file, $block, $start, $end);
		ob_end_clean();
	}
 
	return $content;
}

As much as I've tried, I cannot nest a partial and pass additional data to is, such as on line 10 of view.php .

<?php $nav = view('nav', array('links'=> $links_array))); ?>

Does the passed data need to be in a set array format?

In my case there is a variable $settings set on the index page.

This is passed to the view function,

echo view('home', $settings);

The home.php template file references the passed $settings variable, but then nothing happens

<?php
  $nav = view('partials/nav', array('links' => $settings['menu']));
?>

I created a small test project, adding an index file, that calls the view function.
https://github.com/onebitrocket/php-ti