<?php
/***************************************************************************  
 *                              template.inc
 *                            -------------------                         
 *   begin                : Saturday, Feb 13, 2001 
 *   copyright            : (C) 2001 The phpBB Group        
 *   email                : support@phpbb.com                           
 *                                                          
 *   $Id$
 *                                                            
 * 
 ***************************************************************************/ 

/***************************************************************************  
 *                                                     
 *   This program is free software; you can redistribute it and/or modify    
 *   it under the terms of the GNU General Public License as published by   
 *   the Free Software Foundation; either version 2 of the License, or  
 *   (at your option) any later version.                      
 *                                                          
 * 
 ***************************************************************************/ 

/**
 * Template class. By Nathan Codding of the phpBB group.
 * The interface was originally inspired by PHPLib templates,
 * and the template file formats are quite similar.
 *  
 */


// global variable that holds all the data we'll be substituting into
// the compiled templates.

// This will end up being a multi-dimensional array like this:
// $_tpldata[block.][iteration#][child.][iteration#][child2.][iteration#][variablename] == value
// if it's a root-level variable, it'll be like this:
// $_tpldata[.][0][varname] == value

if (!isset($_tpldata))
{
	$_tpldata = array();
}


class Template {
  var $classname = "Template";

  // Hash of filenames for each template handle.
  var $files = array();

  // Root template directory.
  var $root = "";
  
  // this will hash handle names to the compiled code for that handle.
  var $compiled_code = array();
  
  // This will hold the uncompiled code for that handle.
  var $uncompiled_code = array();
  
  /**
   * Constructor. Simply sets the root dir.
   * 
   */
  function Template($root = ".") 
  {
    $this->set_rootdir($root);
  }

	/**
	 * Destroys this template object. Should be called when you're done with it, in order
	 * to clear out the template data so you can load/parse a new template set.
	 */
	function destroy()
	{
		global $_tpldata;
		$_tpldata = array();
	}

  /**
   * Sets the template root directory for this Template object.
   */  
  function set_rootdir($dir) 
  {
    if (!is_dir($dir)) 
    {
      return false;
    }
    
    $this->root = $dir;
    return true;
  }

  /** 
   * Sets the template filenames for handles. $filename_array
   * should be a hash of handle => filename pairs.
   */
  function set_filenames($filename_array) 
  {
  	if (!is_array($filename_array))
  	{
  		return false;	
  	}
  	
		reset($filename_array);
		while(list($handle, $filename) = each($filename_array)) 
		{
		  $this->files[$handle] = $this->make_filename($filename);
		}
		
		return true;
  }

  
  /**
   * Load the file for the handle, compile the file,
   * and run the compiled code. This will print out
   * the results of executing the template.
   */
  function pparse($handle)
  {
  	global $_tpldata;
  	
  	if (!$this->loadfile($handle))
  	{
  		die("Template->pparse(): Couldn't load template file for handle $handle");	
  	}
  	
  	// actually compile the template now.
  	if (!isset($this->compiled_code[$handle]) || empty($this->compiled_code[$handle]))
  	{
  		// Actually compile the code now.
    	$this->compiled_code[$handle] = $this->compile($this->uncompiled_code[$handle]);
  	}
  	
  	// Run the compiled code.
  	eval($this->compiled_code[$handle]);

		return true;
  }
  
  /**
   * Inserts the uncompiled code for $handle as the
   * value of $varname in the root-level. This can be used
   * to effectively include a template in the middle of another 
   * template.
   * Note that all desired assignments to the variables in $handle should be done
   * BEFORE calling this function.
   */
  function assign_var_from_handle($varname, $handle)
  {
  	global $_tpldata;
  	if (!$this->loadfile($handle))
  	{
  		die("Template->assign_var_from_handle(): Couldn't load template file for handle $handle");	
  	}
  	
  	// Compile it, with the "no echo statements" option on.
  	$code = $this->compile($this->uncompiled_code[$handle], true);
  	// turn it into a variable assignment.
  	$code = '$_str = \'' . $code . '\';';
  	
  	// evaluate the variable assignment.
  	eval($code);
  	
  	// assign the value of the generated variable to the given varname.
  	$this->assign_var($varname, $_str);
  	
  	return true;
  }
  
  /**
   * Block-level variable assignment. Adds a new block iteration with the given
   * variable assignments. Note that this should only be called once per block 
   * iteration.
   */
  function assign_block_vars($blockname, $vararray)
  {
  	global $_tpldata;
  	
  	if (strstr($blockname, '.'))
  	{
  		// Nested block.	
  		$blocks = explode('.', $blockname);
  		$blockcount = sizeof($blocks) - 1;
  		$str = '$_tpldata';
  		for ($i = 0; $i < $blockcount; $i++)
  		{
  			$str .= '[\'' . $blocks[$i] . '.\']';
  			eval('$lastiteration = sizeof(' . $str . ') - 1;');
  			$str .= '[' . $lastiteration . ']';
  		}
  		// Now we add the block that we're actually assigning to.
  		// We're adding a new iteration to this block with the given
  		// variable assignments.
  		$str .= '[\'' . $blocks[$blockcount] . '.\'][] = $vararray;';
  		
  		// Now we evaluate this assignment we've built up.
  		eval($str);
  	}
  	else
  	{
  		// Top-level block.
  		// Add a new iteration to this block with the variable assignments
  		// we were given.
  		$_tpldata[$blockname . '.'][] = $vararray;
  	}
  	
  	return true;
  }
  
  /**
   * Root-level variable assignment. Adds to current assignments, overriding
   * any existing variable assignment with the same name.
   */
  function assign_vars($vararray)
  {
  	global $_tpldata;
  	
  	reset ($vararray);
  	while (list($key, $val) = each($vararray))
  	{
  		$_tpldata['.'][0][$key] = $val;	
  	}
  	
  	return true;
  }
  
	/**
   * Root-level variable assignment. Adds to current assignments, overriding
   * any existing variable assignment with the same name.
   */
	function assign_var($varname, $varval)
	{
		global $_tpldata;
		
		$_tpldata['.'][0][$varname] = $varval;
		
		return true;	
	}
	  
  
  /** 
   * Generates a full path+filename for the given filename, which can either
   * be an absolute name, or a name relative to the rootdir for this Template
   * object.
   */
  function make_filename($filename) 
  {
    // Check if it's an absolute or relative path.
    if (substr($filename, 0, 1) != '/')
    {
      $filename = $this->root . '/' . $filename;
    }
    
    if (!file_exists($filename))
    {
      die("Template->make_filename(): Error - file $filename does not exist");
    }
    
    return $filename;
  }
  
	
  /**
   * If not already done, load the file for the given handle and populate
   * the uncompiled_code[] hash with its code. Do not compile.
   */
  function loadfile($handle) 
  {
  	global $_tpldata;
  	
    // If the file for this handle is already loaded and compiled, do nothing.
    if (isset($this->uncompiled_code[$handle]) && !empty($this->uncompiled_code[$handle]))
    {
      return true;
    }

		// If we don't have a file assigned to this handle, die.
    if (!isset($this->files[$handle])) 
    {
      die("Template->loadfile(): No file specified for handle $handle");
    }
    
    $filename = $this->files[$handle];

    $str = implode("", @file($filename));
    if (empty($str)) 
    {
      die("Template->loadfile(): File $filename for handle $handle is empty");
    }
		
		$this->uncompiled_code[$handle] = $str;
    
    return true;
  }
  
  
  
	/**
	 * Compiles the given string of code, and returns
	 * the result in a string.
	 * If "do_not_echo" is true, the returned code will not be directly
	 * executable, but can be used as part of a variable assignment 
	 * for use in assign_code_from_handle().
	 */
	function compile($code, $do_not_echo = false)
	{
		global $_tpldata;
		
		// replace \ with \\ and then ' with \'.
		$code = str_replace('\\', '\\\\', $code);
		$code = str_replace('\'', '\\\'', $code);
		
		// change template varrefs into PHP varrefs
		
		// This one will handle varrefs WITH namespaces
		$varrefs = array();
		preg_match_all('#\{(([a-z0-9\-_]+?\.)+?)([a-z0-9\-_]+?)\}#is', $code, $varrefs);
		$varcount = sizeof($varrefs[1]);
		for ($i = 0; $i < $varcount; $i++)
		{
			$namespace = $varrefs[1][$i];
			$varname = $varrefs[3][$i];
			$new = $this->generate_block_varref($namespace, $varname);
			
			$code = str_replace($varrefs[0][$i], $new, $code);
		}
		
		// This will handle the remaining root-level varrefs
		$code = preg_replace('#\{([a-z0-9\-_]*?)\}#is', '\' . $_tpldata[\'.\'][0][\'\1\'] . \'', $code);
		
		// Break it up into lines.
		$code_lines = explode("\n", $code);
		
		$block_nesting_level = 0;
		$block_names = array();
		$block_names[0] = ".";
		
		// Second: prepend echo ', append ' . "\n"; to each line.
		$line_count = sizeof($code_lines);
		for ($i = 0; $i < $line_count; $i++)
		{
			$code_lines[$i] = chop($code_lines[$i]);
			if (preg_match('#<!-- BEGIN (.*?) -->#', $code_lines[$i], $m))
			{
				// We have the start of a block.
				$block_nesting_level++;
				$block_names[$block_nesting_level] = $m[1];
				
				if ($block_nesting_level < 2)
				{
					// Block is not nested.
					$code_lines[$i] = '$_' . $m[1] . '_count = sizeof($_tpldata[\'' . $m[1] . '.\']);';
					$code_lines[$i] .= "\n" . 'for ($_' . $m[1] . '_i = 0; $_' . $m[1] . '_i < $_' . $m[1] . '_count; $_' . $m[1] . '_i++)';
					$code_lines[$i] .= "\n" . '{';
				}
				else
				{
					// This block is nested.
					
					// Generate a namespace string for this block.
					$namespace = implode('.', $block_names);
					// strip leading period from root level..
					$namespace = substr($namespace, 2);
					// Get a reference to the data array for this block that depends on the 
					// current indices of all parent blocks.
					$varref = $this->generate_block_data_ref($namespace, false);
					// Create the for loop code to iterate over this block.
					$code_lines[$i] = '$_' . $m[1] . '_count = sizeof(' . $varref . ');';
					$code_lines[$i] .= "\n" . 'for ($_' . $m[1] . '_i = 0; $_' . $m[1] . '_i < $_' . $m[1] . '_count; $_' . $m[1] . '_i++)';
					$code_lines[$i] .= "\n" . '{';
				}
			}
			else if (preg_match('#<!-- END (.*?) -->#', $code_lines[$i], $m))
			{
				// We have the end of a block.
				unset($block_names[$block_nesting_level]);
				$block_nesting_level--;
				$code_lines[$i] = '} // END ' . $m[1];
			}
			else
			{
				// We have an ordinary line of code.
				if (!$do_not_echo)
				{
					$code_lines[$i] = 'echo \'' . $code_lines[$i] . '\' . "\\n";';
				}
			}
			
		}
		
		// Bring it back into a single string of lines of code.
		$code = implode("\n", $code_lines);
			
		return $code	;
		
	}
  
  
  /**
   * Generates a reference to the given variable inside the given (possibly nested)
   * block namespace. This is a string of the form:
   * ' . $_tpldata['parent'][$_parent_i]['$child1'][$_child1_i]['$child2'][$_child2_i]...['varname'] . '
   * It's ready to be inserted into an "echo" line in one of the templates.
   * NOTE: expects a trailing "." on the namespace.
   */
  function generate_block_varref($namespace, $varname)
  {
  	// Strip the trailing period.
  	$namespace = substr($namespace, 0, strlen($namespace) - 1);
  	
  	// Get a reference to the data block for this namespace.
  	$varref = $this->generate_block_data_ref($namespace, true);
  	// Prepend the necessary code to stick this in an echo line.
  	$varref = '\' . ' . $varref;
  	// Append the variable reference.
  	$varref .= '[\'' . $varname . '\'] . \'';
  	
  	return $varref;
  		
  }
  
  
	/**
	 * Generates a reference to the array of data values for the given 
	 * (possibly nested) block namespace. This is a string of the form:
	 * $_tpldata['parent'][$_parent_i]['$child1'][$_child1_i]['$child2'][$_child2_i]...['$childN']
	 *
	 * If $include_last_iterator is true, then [$_childN_i] will be appended to the form shown above.
	 * NOTE: does not expect a trailing "." on the blockname.
	 */
  function generate_block_data_ref($blockname, $include_last_iterator)
  {
  	// Get an array of the blocks involved.
  	$blocks = explode(".", $blockname);
  	$blockcount = sizeof($blocks) - 1;
  	$varref = '$_tpldata';
  	// Build up the string with everything but the last child.
  	for ($i = 0; $i < $blockcount; $i++)
  	{
  		$varref .= '[\'' . $blocks[$i] . '.\'][$_' . $blocks[$i] . '_i]';	
  	}
  	// Add the block reference for the last child.
  	$varref .= '[\'' . $blocks[$blockcount] . '.\']';
  	// Add the iterator for the last child if requried.
  	if ($include_last_iterator)
  	{
  		$varref .= '[$_' . $blocks[$blockcount] . '_i]';
  	}
  	
  	return $varref;
  }

}
?>