<?php
   /***************************************************************/
   /* Template - a PHP templating library 

      Software License Agreement (BSD License)

      Copyright (C) 2007, Edward Eliot.
      All rights reserved.
   
      Redistribution and use in source and binary forms, with or without
      modification, are permitted provided that the following conditions are met:

         * Redistributions of source code must retain the above copyright
           notice, this list of conditions and the following disclaimer.
         * Redistributions in binary form must reproduce the above copyright
           notice, this list of conditions and the following disclaimer in the
           documentation and/or other materials provided with the distribution.
         * Neither the name of Edward Eliot nor the names of its contributors 
           may be used to endorse or promote products derived from this software 
           without specific prior written permission of Edward Eliot.

      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS" AND ANY
      EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
      WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
      DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
      DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
      (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
      LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
      ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
      SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

      Last Updated:  15th June 2007
                                                                  */
   /***************************************************************/
   
   // templates base path
   define('TEMPLATE_PATH', 'templates/');
   
   // enable / disable debugging mode, this will cause problems with doctype and trigger quirks mode so best used as quick test
   define('TEMPLATE_DEBUG', false);
   
   // should HTML be stripped from assigned variables by default
   define('TEMPLATE_STRIP_HTML', true);
   
   // should HTML entities be converted automatically
   define('TEMPLATE_CONVERT_ENTITIES', false);
   define('TEMPLATE_ENCODING', 'ISO-8859-1'); // if so what charset to use
   
   class Template {
      protected $sTemplate;
      protected $sTemplatePath;
      protected $aVars = array();
      protected $aPostFilters = array();
      protected $bDebug;
      
      public function __construct($sTemplate, $sTemplatePath = TEMPLATE_PATH, $bDebug = TEMPLATE_DEBUG) {
         $this->sTemplate = $sTemplate;
         $this->sTemplatePath = $sTemplatePath;
         $this->bDebug = $bDebug;
      }
      
      public function Set($sName, $vValue, $bStripHtml = TEMPLATE_STRIP_HTML, $bConvertEntities = TEMPLATE_CONVERT_ENTITIES, $sCharSet = TEMPLATE_ENCODING) {
         $this->aVars[$sName] = $vValue;
         
         // variable value might be a reference to a sub-template
         if (!($vValue instanceof Template) && is_scalar($vValue)) {
            if ($bStripHtml) {
               $this->aVars[$sName] = strip_tags($this->aVars[$sName]);
            }

            if ($bConvertEntities) {
               $this->aVars[$sName] = htmlentities($this->aVars[$sName], $sCharSet);
            }
         }
      }
      
      public function AddPostFilter($sFunctionName) {
         $this->aPostFilters[] = $sFunctionName;
      }
      
      public function Display() {
         $sOutput = '';
         
         // looping rather than using extract because we need to determine the value type before assigning
         foreach ($this->aVars as $sKey => &$vValue) {
            // is this variable a reference to a sub-template
            if ($vValue instanceof Template) {
               // pass variables from parent to sub-template but don't override variables in sub-template if they already exist as they are more specific
               foreach ($this->aVars as $sSubKey => $vSubValue) {
                  if (!($vSubValue instanceof Template) && !array_key_exists($sSubKey, $vValue->aVars)) {
                     $vValue->aVars[$sSubKey] = $vSubValue;
                  }
               }
               // display sub-template and assign output to parent variable
               $$sKey = $vValue->Display();
            } else {
               $$sKey = $vValue;
            }
         }
         if ($this->bDebug) {
            $sOutput .= "\n<!-- start $this->sTemplate -->\n";
         }
         // use output buffers to capture data from require statement and store in variable
         ob_start();
         require($this->sTemplatePath.$this->sTemplate);
         $sOutput .= ob_get_clean();
         if ($this->bDebug) {
            $sOutput .= "\n<!-- end $this->sTemplate -->\n";
         }
         
         // process content against defined post filters
         foreach ($this->aPostFilters as $sPostFilter) {
            $sOutput = $sPostFilter($sOutput);
         }
         return $sOutput;
      }
   }
?>