bayleedev/LayeredTemplate.php

## LayeredTemplate.php
<?php

class LayeredTemplate {

	/**
	 * The methods defined in this class.
	 *
	 * We want to determine if class B (extends A)
	 * has method C, but not if class A has it.
	 *
	 * @var array
	 */
	public static $definedBlocks = array();

	/**
	 * Determines if a block method exists for a given class.
	 * It does not count if defined within a parent.
	 *
	 * @param string $name Name of the block you are searching for.
	 * @return bool
	 */
	public static function blockExists($name) {
		return in_array($name, static::$definedBlocks);
	}

	/**
	 * Iterates the class tree starting from `$class`, finds all that have the `$block`
	 * defined within them, not a parent.
	 *
	 * @param string $class Class to start with.
	 * @param string $block Block method you are searching for.
	 * @return array
	 */
	public static function topTwoClassesWithBlock($class, $block) {
		$classes = array();
		do {
			if ($class::blockExists($block)) {
				$classes[] = $class;
			}
		} while ($class = get_parent_class($class));
		return array_slice($classes, 0, 2);
	}

	/**
	 * Given a list of classes, will statically call all methods `$block` and return their values.
	 *
	 * This calls them "statically" but if within this class structure calls it as an instance
	 * method using PHP magic.
	 *
	 * @param array $classes Classes you want to render the block on.
	 * @param string $block Block method you want to render.
	 * @return array
	 */
	public function renderBlocksOnClasses($classes, $block) {
		$output = array();
		foreach ($classes as $class) {
			$output[] = $class::$block();
		}
		return $output;
	}

	/**
	 * Renders a given block.
	 *
	 * This is necessary to support `{:child}` in themes.
	 *
	 * @param string $blockName Block you wish to process.
	 */
	public function renderBlock($blockName) {
		$classes = static::topTwoClassesWithBlock(get_called_class(), $blockName);
		$output = $this->renderBlocksOnClasses($classes, $blockName);
		if (empty($output[1]) || strpos($output[1], '{:child}') === false) {
			return $output[0];
		}
		return str_replace('{:child}', $output[0], $output[1]);
	}

}

class Theme extends LayeredTemplate {

	public static $definedBlocks = array('main');

	public function main() {
		?><html><head><title><?=$this->title();?></title></head><body><?=$this->body();?></body></html><?php
	}

}

class ChildTheme extends Theme {
	public static $definedBlocks = array('title');
	public function title() {
		return 'foo {:child}';
	}
}

class Guides extends ChildTheme {
	public static $definedBlocks = array();
}

class Acne extends Guides {

	public static $definedBlocks = array('title');
	public function title() {
		return 'bar';
	}

}

class AcnePage2 extends Acne {
	public static $definedBlocks = array();
}


$foo = new AcnePage2();
echo $foo->title() . PHP_EOL; // => "bar"
echo $foo->renderBlock('title') . PHP_EOL; // => "foo bar"

## LayeredTemplate.rb
require 'pry'

class Template
  def main
    "<html><head><title><?=$this->title();?></title></head><body>#{body}</body></html>"
  end

  def two_top_klasses(method)
    klasses = []
    klasses << self.class.instance_method(method).owner
    klasses << klasses[0].ancestors[1].instance_method(method).owner
    klasses
  rescue
    klasses
  end

  def get_klass_method_outputs(method)
    [].tap do |out|
      two_top_klasses(method).each do |klass|
        out.unshift(klass.instance_method(method).bind(self).call)
      end
    end
  end

  def render(method)
    out = get_klass_method_outputs(method)
    out.shift.gsub!('{:child}', out.shift)
  end

end

class ChildTheme < Template
  def title
    "foo {:child}"
  end
end

class Guides < ChildTheme
end

class Acne < Guides
  def title
    "bar"
  end
end

class AcnePage2 < Acne
end

AcnePage2.new.title # => "bar"
p AcnePage2.new.render(:title) # => "foo bar"
	<?php

	class LayeredTemplate {

	/**
	* The methods defined in this class.
	*
	* We want to determine if class B (extends A)
	* has method C, but not if class A has it.
	*
	* @var array
	*/
	public static $definedBlocks = array();

	/**
	* Determines if a block method exists for a given class.
	* It does not count if defined within a parent.
	*
	* @param string $name Name of the block you are searching for.
	* @return bool
	*/
	public static function blockExists($name) {
	return in_array($name, static::$definedBlocks);
	}

	/**
	* Iterates the class tree starting from `$class`, finds all that have the `$block`
	* defined within them, not a parent.
	*
	* @param string $class Class to start with.
	* @param string $block Block method you are searching for.
	* @return array
	*/
	public static function topTwoClassesWithBlock($class, $block) {
	$classes = array();
	do {
	if ($class::blockExists($block)) {
	$classes[] = $class;
	}
	} while ($class = get_parent_class($class));
	return array_slice($classes, 0, 2);
	}

	/**
	* Given a list of classes, will statically call all methods `$block` and return their values.
	*
	* This calls them "statically" but if within this class structure calls it as an instance
	* method using PHP magic.
	*
	* @param array $classes Classes you want to render the block on.
	* @param string $block Block method you want to render.
	* @return array
	*/
	public function renderBlocksOnClasses($classes, $block) {
	$output = array();
	foreach ($classes as $class) {
	$output[] = $class::$block();
	}
	return $output;
	}

	/**
	* Renders a given block.
	*
	* This is necessary to support `{:child}` in themes.
	*
	* @param string $blockName Block you wish to process.
	*/
	public function renderBlock($blockName) {
	$classes = static::topTwoClassesWithBlock(get_called_class(), $blockName);
	$output = $this->renderBlocksOnClasses($classes, $blockName);
	if (empty($output[1]) \|\| strpos($output[1], '{:child}') === false) {
	return $output[0];
	}
	return str_replace('{:child}', $output[0], $output[1]);
	}

	}

	class Theme extends LayeredTemplate {

	public static $definedBlocks = array('main');

	public function main() {
	?><html><head><title><?=$this->title();?></title></head><body><?=$this->body();?></body></html><?php
	}

	}

	class ChildTheme extends Theme {
	public static $definedBlocks = array('title');
	public function title() {
	return 'foo {:child}';
	}
	}

	class Guides extends ChildTheme {
	public static $definedBlocks = array();
	}

	class Acne extends Guides {

	public static $definedBlocks = array('title');
	public function title() {
	return 'bar';
	}

	}

	class AcnePage2 extends Acne {
	public static $definedBlocks = array();
	}


	$foo = new AcnePage2();
	echo $foo->title() . PHP_EOL; // => "bar"
	echo $foo->renderBlock('title') . PHP_EOL; // => "foo bar"
	require 'pry'

	class Template
	def main
	"<html><head><title><?=$this->title();?></title></head><body>#{body}</body></html>"
	end

	def two_top_klasses(method)
	klasses = []
	klasses << self.class.instance_method(method).owner
	klasses << klasses[0].ancestors[1].instance_method(method).owner
	klasses
	rescue
	klasses
	end

	def get_klass_method_outputs(method)
	[].tap do \|out\|
	two_top_klasses(method).each do \|klass\|
	out.unshift(klass.instance_method(method).bind(self).call)
	end
	end
	end

	def render(method)
	out = get_klass_method_outputs(method)
	out.shift.gsub!('{:child}', out.shift)
	end

	end

	class ChildTheme < Template
	def title
	"foo {:child}"
	end
	end

	class Guides < ChildTheme
	end

	class Acne < Guides
	def title
	"bar"
	end
	end

	class AcnePage2 < Acne
	end

	AcnePage2.new.title # => "bar"
	p AcnePage2.new.render(:title) # => "foo bar"