Simple-Templates: The Template-Engine

file1.php

<?php
/**
 * 
 * Abstract class WP Simple Templater creates a copy of the template-class and
 * provide the templates to the template-engine
 * @author Ralf Albert
 *
 */
abstract class WP_Simple_Templater extends Formatter
{
	/**
	 * 
	 * Instance of template-class
	 * @var object $templates_object
	 */
	protected $templates_object = NULL;
	
	/**
	 * 
	 * Constructor
	 * Creates an instance of the template-class and setup the delimiters for Formatter
	 * @param WP_Simple_Templates $templates
	 */
	public function __construct( WP_Simple_Templates $templates ){
		
		$this->templates_object = &$templates;
		
		$this->set_delimiter( '%', '%' );
		
	}
	
	/**
	 * 
	 * Return a template by given type. Returns an wp-error on failure
	 * @param string $type
	 * @return string|bool Return a template-string if it was defined by the template-class. Or false if no such template was defined
	 */
	protected function get_templates( $templatetype = '', $type = '' ){
		
		// error message
		$err_msg = '';
		
		// if the sub-type is empty (e.g the template is a string not an array), use the template-type as sub-type
		if( '' == $type )
			$type = $templatetype;
		
		// first check if a template-type was set
		if( '' == $templatetype )
			$err_msg = 'Empty template-type';
		
		// check if a template-class was loaded
		elseif( NULL === $this->templates_object )
			$err_msg = 'No templates defined in <strong>' . get_class( $this ) . '</strong>';					

		// we have a template-type and a template-class. get the template(s)
		else {
			
			 $template = $this->templates_object->get_templates( $templatetype );

			 // get error-message thrown by template-class
			 if( is_wp_error( $template ) )
			 	$err_msg = $template->get_error_message();

			 // check the template.
			 // convert a string into an array. else check if the requested type is in the template-array
			 else {
			 	
				 if( ! is_array( $template ) )
				 	$template[$type] = $template;
	
				 elseif( ! in_array( $type, array_keys( $template ) ) )
				 	$err_msg = $type . ' is not defined.';

			 }
			 
		}

		// if a error occurs, return an error-object
		if( '' != $err_msg ){
			
			return new WP_Error(
					'template_error',
					sprintf(
						'<div class="error"><h4>Template Error</h4>%s</div>',
						$err_msg
					)
				);
						
		}

		// finally all checks are ok, return the template-array
		return $template;
	
	}
	
}

/**
 * 
 * The concrete class WP Simple HTML insert the data in the templates
 * @author Ralf Albert
 *
 */
class WP_Simple_HTML extends WP_Simple_Templater
{
	
	/**
	 * 
	 * Constructor overrides the delimiters in parent class
	 * @param WP_Simple_Templates $templates
	 */
	public function __construct( WP_Simple_Templates $templates ){
		
		parent::__construct( $templates );
		
		$this->set_delimiter( '{', '}' );
		
	}
	
	/**
	 * 
	 * Create a html list (ul, ol or with div-tag)
	 * @param string $type The type of the list. ul, ol or div
	 * @param array $data Data to display inside the list
	 */
	public function get_list( $type = '', $data = array() ){
	
		// get list templates
		$templates = $this->get_templates( 'list', $type );
		
		if( is_wp_error( $templates ) )
			return $templates->get_error_message();
				
		// create list
		$inner	= new stdClass();
		$values	= new stdClass();
		
		foreach( $data as $key => $value ){
		
			$values->key	= $key;
			$values->item	= $value;
			
			$inner->inner	.= self::sprintf( $templates[$type]['inner'], $values );
			
		}
		
		return self::sprintf( $templates[$type]['outer'], $inner );
	
	}
	
	/**
	 * 
	 * Prints a html-list (ul, ol or with div-tag)
	 * @param string $type The type of the list. ul, ol or div
	 * @param array $data Data to display inside the list
	 */
	public function print_list( $type = '', $data = array() ){

		if( ! is_array( $data ) )
			$data = (array) $data;
		
		echo $this->get_list( $type, $data );
		
	}

	/**
	 * 
	 * Create a H1-headline
	 * @param string $text
	 */
	public function get_headline( $text = '' ){
		
		// get headline template
		$template = $this->get_templates( 'hone' );
		
		if( is_wp_error( $template ) )
			return $template->get_error_message();
				
		$data = new stdClass();
		$data->headline = $text;
			
		return self::sprintf( $template, $data );
		
	}
	
	/**
	 * 
	 * Print a H1-headline
	 * @param string $text
	 */
	public function print_headline( $text = '' ){
		
		echo $this->get_headline( $text );
		
	}

}