path: root/include/template.php

<?php
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// | PhpWebGallery - a PHP based picture gallery                           |
// | Copyright (C) 2002-2003 Pierrick LE GALL - pierrick@phpwebgallery.net |
// | Copyright (C) 2003-2005 PhpWebGallery Team - http://phpwebgallery.net |
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// | it under the terms of the GNU General Public License as published by  |
// | the Free Software Foundation                                          |
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// | 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      |
// | General Public License for more details.                              |
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// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
// | USA.                                                                  |
// +-----------------------------------------------------------------------+

/**
 * 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.
 */

class Template {

  var $classname = "Template";
  
  // 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 :
  // $this->_tpldata[block.][iteration#][child.][iteration#][child2.][iteration#][variablename] == value
  // if it's a root-level variable, it'll be like this:
  // $this->_tpldata[.][0][varname] == value
  var $_tpldata = array();
  
  // 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()
    {
      $this->_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($handle)
    {
      if (!$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.
      //echo ("<!-- ".$this->compiled_code[$handle]." -->");
      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, $handle)
    {
      if (!$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.
      $_str = "";
      $code = $this->compile($this->uncompiled_code[$handle], true, '_str');
      
      // 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, $vararray)
    {
      if (strstr($blockname, '.'))
      {
        // Nested block.
        $blocks = explode('.', $blockname);
        $blockcount = sizeof($blocks) - 1;
        $str = '$this->_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.
        $this->_tpldata[$blockname . '.'][] = $vararray;
      }
      
      return true;
    }
  
  /**
   * Root-level variable assignment. Adds to current assignments, overriding
   * any existing variable assignment with the same name.
   */
  function assign_vars($vararray)
    {
      reset ($vararray);
      while (list($key, $val) = each($vararray))
      {
        $this->_tpldata['.'][0][$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)
    {
      $this->_tpldata['.'][0][$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) != '/')
      {
        $filename = realpath($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($handle)
    {
      // If the file for this handle is already loaded and compiled, do
      // nothing.
      if (isset($this->uncompiled_code[$handle])
          and !empty($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, $retvar = '')
    {
      // 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
      $code = preg_replace('#\{([a-z0-9\-_]*?)\}#is', '\' . ( ( isset($this->_tpldata[\'.\'][0][\'\1\']) ) ? $this->_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))
        {
          $n[0] = $m[0];
          $n[1] = $m[1];
          
          // Added: dougk_ff7-Keeps templates from bombing if begin is on
          // the same line as end.. I think. :)
          if ( preg_match('#<!-- END (.*?) -->#', $code_lines[$i], $n) )
          {
            $block_nesting_level++;
            $block_names[$block_nesting_level] = $m[1];
            if ($block_nesting_level < 2)
            {
              // Block is not nested.
              $code_lines[$i] = '$_' . $n[1] . '_count = ( isset($this->_tpldata[\'' . $n[1] . '.\']) ) ?  sizeof($this->_tpldata[\'' . $n[1] . '.\']) : 0;';
              $code_lines[$i] .= "\n" . 'for ($_' . $n[1] . '_i = 0; $_' . $n[1] . '_i < $_' . $n[1] . '_count; $_' . $n[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] = '$_' . $n[1] . '_count = ( isset(' . $varref . ') ) ? sizeof(' . $varref . ') : 0;';
              $code_lines[$i] .= "\n" . 'for ($_' . $n[1] . '_i = 0; $_' . $n[1] . '_i < $_' . $n[1] . '_count; $_' . $n[1] . '_i++)';
              $code_lines[$i] .= "\n" . '{';
            }
            
            // We have the end of a block.
            unset($block_names[$block_nesting_level]);
            $block_nesting_level--;
            $code_lines[$i] .= '} // END ' . $n[1];
            $m[0] = $n[0];
            $m[1] = $n[1];
          }
          else
          {
            // 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] = '$_' . $m[1] . '_count = ( isset($this->_tpldata[\'' . $m[1] . '.\']) ) ? sizeof($this->_tpldata[\'' . $m[1] . '.\']) : 0;';
              $code_lines[$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 = ( isset(' . $varref . ') ) ? sizeof(' . $varref . ') : 0;';
              $code_lines[$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";';
          }
          else
          {
            $code_lines[$i] = '$' . $retvar . '.= \'' . $code_lines[$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: '
   * . $this->_tpldata['parent'][$_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.
      
      // Append the variable reference.
      $varref .= '[\'' . $varname . '\']';
      
      $varref = '\' . ( ( isset(' . $varref . ') ) ? ' . $varref . ' : \'\' ) . \'';
      
      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:
   * $this->_tpldata['parent'][$_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;
      $varref = '$this->_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;
    }
  
}

?>