savant2.php

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<?php

/**
* 
* Error constants.
* 
*/

define('SAVANT2_ERROR_ASSIGN',       -1);
define('SAVANT2_ERROR_ASSIGNREF',    -2);
define('SAVANT2_ERROR_COMPILER',     -3);
define('SAVANT2_ERROR_NOFILTER',     -4);
define('SAVANT2_ERROR_NOPLUGIN',     -5);
define('SAVANT2_ERROR_NOSCRIPT',     -6);
define('SAVANT2_ERROR_NOTEMPLATE',   -7);
define('SAVANT2_ERROR_COMPILE_FAIL', -8);


/**
* 
* Error messages.
* 
*/

if (! isset($GLOBALS['_SAVANT2']['error'])) {
	$GLOBALS['_SAVANT2']['error'] = array(
		SAVANT2_ERROR_ASSIGN       => 'assign() parameters not correct',
		SAVANT2_ERROR_ASSIGNREF    => 'assignRef() parameters not correct',
		SAVANT2_ERROR_COMPILER     => 'compiler not an object or has no compile() method',
		SAVANT2_ERROR_NOFILTER     => 'filter file not found',
		SAVANT2_ERROR_NOPLUGIN     => 'plugin file not found',
		SAVANT2_ERROR_NOSCRIPT     => 'compiled template script file not found',
		SAVANT2_ERROR_NOTEMPLATE   => 'template source file not found',
		SAVANT2_ERROR_COMPILE_FAIL => 'template source failed to compile'
	);
}


/**
* 
* Provides an object-oriented template system.
* 
* Savant2 helps you separate model logic from view logic using PHP as
* the template language. By default, Savant2 does not compile templates.
* However, you may pass an optional compiler object to compile template
* source to include-able PHP code.
* 
* Please see the documentation at {@link http://phpsavant.com/}, and be
* sure to donate! :-)
* 
* $Id: Savant2.php,v 1.32 2006/03/05 16:58:38 pmjones Exp $
* 
* @author Paul M. Jones <[e-mail]>
* 
* @package Savant2
* 
* @version 2.4.3 stable
* 
* @license LGPL http://www.gnu.org/copyleft/lesser.html
* 
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
* 
*/

class Savant2 {
	
	
	/**
	* 
	* PHP5 ONLY:  Whether or not to use __autoload().  Default is false.
	* 
	* @access private
	* 
	* @var bool
	* 
	*/
	
	var $_autoload = false;
	
	
	/**
	* 
	* PHP5 ONLY: What method __call() will alias to.
	* 
	* Generally 'plugin' or 'splugin' (as __call() is intended for those).
	* 
	* @access private
	* 
	* @var string
	* 
	*/
	
	var $_call = 'plugin';
	
	
	/**
	* 
	* The custom compiler (pre-processor) object, if any.
	* 
	* @access private
	* 
	* @var object
	* 
	*/
	
	var $_compiler = null;
	
	
	/**
	* 
	* The class type to use when instantiating error objects.
	* 
	* @access private
	* 
	* @var string
	* 
	*/
	
	var $_error = null;
	
	
	/**
	* 
	* Array of callbacks used to escape output.
	* 
	* @access private
	* 
	* @var array
	* 
	* @see setEscape()
	* 
	* @see addEscape()
	* 
	* @see escape()
	* 
	* @see _()
	* 
	*/
	
	var $_escape = array('htmlspecialchars');
	
	
	/**
	* 
	* Whether or not to extract assigned variables into fetch() scope.
	* 
	* When true, all variables and references assigned to Savant2 are
	* extracted into the local scope of the template script at fetch()
	* time, and may be addressed as "$varname" instead of
	* "$this->varname".  The "$this->varname" notation will also work.
	* 
	* When false, you //must// use "$this->varname" in your templates to
	* address a variable instead of "$varname".  This has three
	* benefits: speed (no time spent extracting variables), memory use
	* (saves RAM by not making new references to variables), and clarity
	* (any $this->varname is obviously an assigned var, and vars created
	* within the template are not prefixed with $this).
	* 
	* @access private
	* 
	* @var bool
	* 
	*/
	
	var $_extract = false;
	
	
	/**
	* 
	* The output of the template script.
	* 
	* @access private
	* 
	* @var string
	* 
	*/
	
	var $_output = null;
	
	
	/**
	* 
	* The set of search directories for resources (plugins/filters) and
	* templates.
	* 
	* @access private
	* 
	* @var array
	* 
	*/
	
	var $_path = array(
		'resource' => array(),
		'template' => array()
	);
	
	
	/**
	* 
	* Array of resource (plugin/filter) object instances.
	* 
	* @access private
	* 
	* @var array
	* 
	*/
	
	var $_resource = array(
		'plugin' => array(),
		'filter' => array()
	);
	
	
	/**
	* 
	* Whether or not to automatically self-reference in plugins and filters.
	* 
	* @access private
	* 
	* @var bool
	* 
	*/
	
	var $_reference = false;
	
	
	/**
	* 
	* Whether or not to restrict template includes only to registered paths.
	* 
	* @access private
	* 
	* @var bool
	* 
	*/
	
	var $_restrict = false;
	
	
	/**
	* 
	* The path to the compiled template script file.
	* 
	* By default, the template source and template script are the same file.
	*
	* @access private
	* 
	* @var string
	* 
	*/
	
	var $_script = null;
	
	
	/**
	* 
	* The name of the default template source file.
	* 
	* @access private
	* 
	* @var string
	* 
	*/
	
	var $_template = null;
	
	
	// -----------------------------------------------------------------
	//
	// Constructor and general property setters
	//
	// -----------------------------------------------------------------
	
	
	/**
	* 
	* Constructor.
	* 
	* @access public
	* 
	* @param array $conf An associative array of configuration keys for
	* the Savant2 object.  Any, or none, of the keys may be set. The
	* keys are:
	* 
	* 'template_path' => The default path string or array of directories
	* to search for templates.
	* 
	* 'resource_path' => The default path string or array of directories
	* to search for plugin and filter resources.
	* 
	* 'error' => The custom error class that Savant2 should use
	* when returning errors.
	* 
	* 'extract' => Whether or not to extract variables into the local
	* scope when executing a template.
	* 
	* 'template' => The default template source name to use.
	* 
	*/
	
	function Savant2($conf = array())
	{
		// set the default template search dirs
		if (isset($conf['template_path'])) {
			// user-defined dirs
			$this->setPath('template', $conf['template_path']);
		} else {
			// default directory only
			$this->setPath('template', null);
		}
		
		// set the default filter search dirs
		if (isset($conf['resource_path'])) {
			// user-defined dirs
			$this->setPath('resource', $conf['resource_path']);
		} else {
			// default directory only
			$this->setPath('resource', null);
		}
		
		// do we allow __autoload() use?
		if (isset($conf['autoload'])) {
			$this->setAutoload($conf['autoload']);
		}
		
		// set the error class
		if (isset($conf['error'])) {
			$this->setError($conf['error']);
		}
		
		// set the extraction flag
		if (isset($conf['extract'])) {
			$this->setExtract($conf['extract']);
		}
		
		// set the restrict flag
		if (isset($conf['restrict'])) {
			$this->setRestrict($conf['restrict']);
		}
		
		// set the Savant reference flag
		if (isset($conf['reference'])) {
			$this->setReference($conf['reference']);
		}
		
		// set the default template
		if (isset($conf['template'])) {
			$this->setTemplate($conf['template']);
		}
		
		// set the output escaping callbacks
		if (isset($config['escape'])) {
			call_user_func_array(
				array($this, 'setEscape'),
				(array) $config['escape']
			);
		}	
	}
	
	/**
	* 
	* Sets whether or not __autoload() is used when loading classes.
	* 
	* @access public
	* 
	* @param bool $flag True to use __autoload(), false to not use it.
	* 
	* @return void
	* 
	*/
	
	function setAutoload($flag) {
		$this->_autoload = (bool) $flag;
	}
	
	
	/**
	* 
	* Sets a custom compiler/pre-processor for template sources.
	* 
	* By default, Savant2 does not use a compiler; use this to set your
	* own custom compiler (pre-processor) for template sources.
	* 
	* @access public
	* 
	* @param object $compiler The compiler object; it must have a
	* "compile()" method.  If null or false, the current compiler object
	* is removed from Savant2.
	* 
	* @return void
	* 
	* @throws object An error object with a SAVANT2_ERROR_COMPILER code.
	* 
	*/
	
	function setCompiler(&$compiler)
	{
		if (! $compiler) {
			// nullify any current compiler
			$this->_compiler = null;
		} elseif (is_object($compiler) && method_exists($compiler, 'compile')) {
			// refer to a compiler object
			$this->_compiler =& $compiler;
		} else {
			// no usable compiler passed
			$this->_compiler = null;
			return $this->error(SAVANT2_ERROR_COMPILER);
		}
	}
	
	
	/**
	* 
	* Sets the method that __call() will alias to.
	* 
	* @access public
	* 
	* @param string $method The Savant2 method for __call() to alias to,
	* generally 'plugin' or 'splugin'.
	* 
	* @return void
	* 
	*/
	
	function setCall($method = 'plugin')
	{
		$this->_call = $method;
	}
	
	
	/**
	* 
	* Sets the custom error class for Savant2 errors.
	* 
	* @access public
	* 
	* @param string $error The name of the custom error class name; if
	* null or false, resets the error class to 'Savant2_Error'.
	* 
	* @return void
	* 
	*/
	
	function setError($error)
	{
		if (! $error) {
			$this->_error = null;
		} else {
			$this->_error = $error;
		}
	}
	
	
	/**
	*
	* Turns path checking on/off.
	* 
	* @access public
	*
	* @param bool $flag True to turn on path checks, false to turn off.
	*
	* @return void
	*
	*/
	
	function setRestrict($flag = false)
	{
		if ($flag) {
			$this->_restrict = true;
		} else {
			$this->_restrict = false;
		}
	}
	
	
	/**
	*
	* Turns extraction of variables on/off.
	* 
	* @access public
	*
	* @param bool $flag True to turn on extraction, false to turn off.
	*
	* @return void
	*
	*/
	
	function setExtract($flag = true)
	{
		if ($flag) {
			$this->_extract = true;
		} else {
			$this->_extract = false;
		}
	}
	
	
	/**
	*
	* Sets the automated Savant reference for plugins and filters.
	*
	* @access public
	*
	* @param bool $flag Whether to reference Savant2 or not.
	*
	* @return void
	*
	*/
	
	function setReference($flag = false)
	{
		$this->_reference = $flag;
	}
	
	
	/**
	*
	* Sets the default template name.
	*
	* @access public
	*
	* @param string $template The default template name.
	*
	* @return void
	*
	*/
	
	function setTemplate($template)
	{
		$this->_template = $template;
	}
	
	
	/**
	* 
	* Internal version of class_exists() to allow for differing behaviors.
	* 
	* Under PHP4, there is only 1 param to class_exists(); in PHP5, there 
	* are two.  However, if you pass 2 params to the PHP4 version, you get
	* a parameter count warning; hence, this method.
	* 
	* Under PHP5, checks $this->_autload to see if __autoload() should be
	* called.
	* 
	* @access public
	* 
	* @param string $class A class name.
	* 
	* @return bool Whether or not the class exists.
	* 
	*/
	
	function _classExists($class) {
		if (PHP_VERSION < '5') {
			// version 4.x
			return class_exists($class);
		} else {
			// version 5.x
			return class_exists($class, $this->_autoload);
		}
	}
	
	
	// -----------------------------------------------------------------
	//
	// Output escaping and management.
	//
	// -----------------------------------------------------------------
	
	
	/**
	* 
	* Clears then sets the callbacks to use when calling $this->escape().
	* 
	* Each parameter passed to this function is treated as a separate
	* callback.  For example:
	* 
	* <code>
	* $savant->setEscape(
	*	 'stripslashes',
	*	 'htmlspecialchars',
	*	 array('StaticClass', 'method'),
	*	 array($object, $method)
	* );
	* </code>
	* 
	* @access public
	*
	* @return void
	*