<?php

 /*

  * Session Management for PHP3

  *

  * (C) Copyright 1999-2000 NetUSE GmbH

  *                    Kristian Koehntopp

  *

  * $Id: template.class.php,v 1.9 2008/06/26 00:26:43 blaine Exp $

  *

  */

 /*

  * Change log since version 7.2c

  *

  * Bug fixes to version 7.2c compiled by Richard Archer <rha@juggernaut.com.au>:

  * (credits given to first person to post a diff to phplib mailing list)

  *

  * Normalised all comments and whitespace (rha)

  * replaced "$handle" with "$varname" and "$h" with "$v" throughout (from phplib-devel)

  * added braces around all one-line if statements in: get_undefined, loadfile and halt (rha)

  * set_var was missing two sets of braces (rha)

  * added a couple of "return true" statements (rha)

  * set_unknowns had "keep" as default instead of "remove" (from phplib-devel)

  * set_file failed to check for empty strings if passed an array of filenames (phplib-devel)

  * remove @ from call to preg_replace in subst -- report errors if there are any (NickM)

  * set_block unnecessarily required a newline in the template file (Marc Tardif)

  * pparse now calls this->finish to replace undefined vars (Layne Weathers)

  * get_var now checks for unset varnames (NickM & rha)

  * get_var when passed an array used the array key instead of the value (rha)

  * get_vars now uses a call to get_var rather than this->varvals to prevent undefined var warning (rha)

  * in finish, the replacement string referenced an unset variable (rha)

  * loadfile would try to load a file if the varval had been set to "" (rha)

  * in get_undefined, only match non-whitespace in variable tags as in finish (Layne Weathers & rha)

  * more elegant fix to the problem of subst stripping '$n', '\n' and '\\' strings (rha)

  *

  *

  * Changes in functionality which go beyond bug fixes:

  *

  * changed debug handling so set, get and internals can be tracked separately (rha)

  * added debug statements throughout to track most function calls (rha)

  * debug output contained raw HTML -- is now escaped with htmlentities (rha)

  * Alter regex in set_block to remove more whitespace around BEGIN/END tags to improve HTML layout (rha)

  * Add "append" option to set_var, works just like append in parse (dale at linuxwebpro.com, rha)

  * Altered parse so that append is honored if passed an array (Brian)

  * Converted comments and documentation to phpdoc style (rha)

  * Added clear_var to set the value of variables to "" (rha)

  * Added unset_var to usset variables (rha)

  *

  */

 /**

  * The template class allows you to keep your HTML code in some external files

  * which are completely free of PHP code, but contain replacement fields.

  * The class provides you with functions which can fill in the replacement fields

  * with arbitrary strings. These strings can become very large, e.g. entire tables.

  *

  * Note: If you think that this is like FastTemplates, read carefully. It isn't.

  *

  */

 class Template

 {

  /**

   * Serialization helper, the name of this class.

   *

   * @var       string

   * @access    public

   */

   var $classname = 'Template';

  /**

   * Determines how much debugging output Template will produce.

   * This is a bitwise mask of available debug levels:

   * 0 = no debugging

   * 1 = debug variable assignments

   * 2 = debug calls to get variable

   * 4 = debug internals (outputs all function calls with parameters).

   *

   * Note: setting $this->debug = true will enable debugging of variable

   * assignments only which is the same behaviour as versions up to release 7.2d.

   *

   * @var       int

   * @access    public

   */

   var $debug    = false;

  /**

   * The base directory from which template files are loaded.

   *

   * @var       string

   * @access    private

   * @see       set_root

   */

   var $root     = '.';

  /**

   * A hash of strings forming a translation table which translates variable names

   * into names of files containing the variable content.

   * $file[varname] = "filename";

   *

   * @var       array

   * @access    private

   * @see       set_file

   */

   var $file     = array();

  /**

   * A hash of strings forming a translation table which translates variable names

   * into values for their respective varkeys.

   * $varvals[varname] = "value"

   *

   * @var       array

   * @access    private

   * @see       set_var

   */

   var $varvals  = array();

  /**

   * Determines how to output variable tags with no assigned value in templates.

   *

   * @var       string

   * @access    private

   * @see       set_unknowns

   */

   var $unknowns = 'remove';

  /**

   * Determines how Template handles error conditions.

   * "yes"      = the error is reported, then execution is halted

   * "report"   = the error is reported, then execution continues by returning "false"

   * "no"       = errors are silently ignored, and execution resumes reporting "false"

   *

   * @var       string

   * @access    public

   * @see       halt

   */

   var $halt_on_error  = 'yes';

  /**

   * The last error message is retained in this variable.

   *

   * @var       string

   * @access    public

   * @see       halt

   */

   var $last_error     = '';

  /******************************************************************************

   * Class constructor. May be called with two optional parameters.

   * The first parameter sets the template directory the second parameter

   * sets the policy regarding handling of unknown variables.

   *

   * usage: Template([string $root = "."], [string $unknowns = "remove"])

   *

   * @param     $root        path to template directory

   * @param     $string      what to do with undefined variables

   * @see       set_root

   * @see       set_unknowns

   * @access    public

   * @return    void

   */

   function Template($root = '.', $unknowns = 'remove') {

     if ($this->debug & 4) {

       echo "<p><b>Template:</b> root = $root, unknowns = $unknowns</p>\n";

     }

     $this->set_root($root);

     $this->set_unknowns($unknowns);

   }

  /******************************************************************************

   * Checks that $root is a valid directory and if so sets this directory as the

   * base directory from which templates are loaded by storing the value in

   * $this->root. Relative filenames are prepended with the path in $this->root.

   *

   * Returns true on success, false on error.

   *

   * usage: set_root(string $root)

   *

   * @param     $root         string containing new template directory

   * @see       root

   * @access    public

   * @return    boolean

   */

   function set_root($root) {

     if ($this->debug & 4) {

       echo "<p><b>set_root:</b> root = $root</p>\n";

     }

     if (substr ($root, -1) == '/') {

       $root = substr ($root, 0, -1);

     }

     if (!is_dir($root)) {

       $this->halt("set_root: $root is not a directory.");

       return false;

     }

     $this->root = $root;

     return true;

   }

  /******************************************************************************

   * Sets the policy for dealing with unresolved variable names.

   *

   * unknowns defines what to do with undefined template variables

   * "remove"   = remove undefined variables

   * "comment"  = replace undefined variables with comments

   * "keep"     = keep undefined variables

   *

   * Note: "comment" can cause unexpected results when the variable tag is embedded

   * inside an HTML tag, for example a tag which is expected to be replaced with a URL.

   *

   * usage: set_unknowns(string $unknowns)

   *

   * @param     $unknowns         new value for unknowns

   * @see       unknowns

   * @access    public

   * @return    void

   */

   function set_unknowns($unknowns = 'remove') {

     if ($this->debug & 4) {

       echo "<p><b>unknowns:</b> unknowns = $unknowns</p>\n";

     }

     $this->unknowns = $unknowns;

   }

  /******************************************************************************

   * Defines a filename for the initial value of a variable.

   *

   * It may be passed either a varname and a file name as two strings or

   * a hash of strings with the key being the varname and the value

   * being the file name.

   *

   * The new mappings are stored in the array $this->file.

   * The files are not loaded yet, but only when needed.

   *

   * Returns true on success, false on error.

   *

   * usage: set_file(array $filelist = (string $varname => string $filename))

   * or

   * usage: set_file(string $varname, string $filename)

   *

   * @param     $varname      either a string containing a varname or a hash of varname/file name pairs.

   * @param     $filename     if varname is a string this is the filename otherwise filename is not required

   * @access    public

   * @return    boolean

   */

   function set_file($varname, $filename = '') {

     if (!is_array($varname)) {

       if ($this->debug & 4) {

         echo "<p><b>set_file:</b> (with scalar) varname = $varname, filename = $filename</p>\n";

       }

       if ($filename == '') {

         $this->halt("set_file: For varname $varname filename is empty.");

         return false;

       }

       $this->file[$varname] = $this->filename($filename);

     } else {

       foreach ($varname as $v => $f) {

         if ($this->debug & 4) {

           echo "<p><b>set_file:</b> (with array) varname = $v, filename = $f</p>\n";

         }

         if ($f == '') {

           $this->halt("set_file: For varname $v filename is empty.");

           return false;

         }

         $this->file[$v] = $this->filename($f);

       }

     }

     return true;

   }

  /******************************************************************************

   * A variable $parent may contain a variable block defined by:

   * <!-- BEGIN $varname --> content <!-- END $varname -->. This function removes

   * that block from $parent and replaces it with a variable reference named $name.

   * The block is inserted into the varvals hashes. If $name is

   * omitted, it is assumed to be the same as $varname.

   *

   * Blocks may be nested but care must be taken to extract the blocks in order

   * from the innermost block to the outermost block.

   *

   * Returns true on success, false on error.

   *

   * usage: set_block(string $parent, string $varname, [string $name = ""])

   *

   * @param     $parent       a string containing the name of the parent variable

   * @param     $varname      a string containing the name of the block to be extracted

   * @param     $name         the name of the variable in which to store the block

   * @access    public

   * @return    boolean

   */

   function set_block($parent, $varname, $name = '') {

     if ($this->debug & 4) {

       echo "<p><b>set_block:</b> parent = $parent, varname = $varname, name = $name</p>\n";

     }

     if (!$this->loadfile($parent)) {

       $this->halt("set_block: unable to load $parent.");

       return false;

     }

     if ($name == '') {

       $name = $varname;

     }

     $str = $this->get_var($parent);

     $reg = "/[ \t]*<!--\s+BEGIN $varname\s+-->\s*?\n?(\s*.*?\n?)\s*<!--\s+END $varname\s+-->\s*?\n?/sm";

     preg_match_all($reg, $str, $m);

     $str = str_replace($m[0][0], '{' . $name . '}', $str);

     $this->set_var($varname, $m[1][0]);

     $this->set_var($parent, $str);

     return true;

   }

  /******************************************************************************

   * This functions sets the value of a variable.

   *

   * It may be called with either a varname and a value as two strings or an

   * an associative array with the key being the varname and the value being

   * the new variable value.

   *

   * The function inserts the new value of the variable into the $varvals hashes.

   * It is not necessary for a variable to exist in these hashes before calling

   * this function.

   *

   * An optional third parameter allows the value for each varname to be appended

   * to the existing variable instead of replacing it. The default is to replace.

   * This feature was introduced after the 7.2d release.

   *

   *

   * usage: set_var(string $varname, [string $value = ""], [boolean $append = false])

   * or

   * usage: set_var(array $varname = (string $varname => string $value), [mixed $dummy_var], [boolean $append = false])

   *

   * @param     $varname      either a string containing a varname or a hash of varname/value pairs.

   * @param     $value        if $varname is a string this contains the new value for the variable otherwise this parameter is ignored

   * @param     $append       if true, the value is appended to the variable's existing value

   * @access    public

   * @return    void

   */

   function set_var($varname, $value = '', $append = false) {

     if (!is_array($varname)) {

       if (!empty($varname)) {

         if ($this->debug & 1) {

           printf("<b>set_var:</b> (with scalar) <b>%s</b> = '%s'<br" . XHTML . ">\n", $varname, htmlentities($value));

         }

         if ($append && isset($this->varvals[$varname])) {

           $this->varvals[$varname] .= $value;

         } else {

           $this->varvals[$varname] = $value;

         }

       }

     } else {

       foreach ($varname as $k => $v) {

         if (!empty($k)) {

           if ($this->debug & 1) {

             printf("<b>set_var:</b> (with array) <b>%s</b> = '%s'<br" . XHTML . ">\n", $k, htmlentities($v));

           }

           if ($append && isset($this->varvals[$k])) {

             $this->varvals[$k] .= $v;

           } else {

             $this->varvals[$k] = $v;

           }

         }

       }

     }

   }

  /******************************************************************************

   * This functions clears the value of a variable.

   *

   * It may be called with either a varname as a string or an array with the 

   * values being the varnames to be cleared.

   *

   * The function sets the value of the variable in the $varvals hashes to "".

   * It is not necessary for a variable to exist in these hashes before calling

   * this function.

   *

   *

   * usage: clear_var(string $varname)

   * or

   * usage: clear_var(array $varname = (string $varname))

   *

   * @param     $varname      either a string containing a varname or an array of varnames.

   * @access    public

   * @return    void

   */

   function clear_var($varname) {

     if (!is_array($varname)) {

       if (!empty($varname)) {

         if ($this->debug & 1) {

           printf("<b>clear_var:</b> (with scalar) <b>%s</b><br" . XHTML . ">\n", $varname);

         }

         $this->set_var($varname, '');

       }

     } else {

       foreach ($varname as $v) {

         if (!empty($v)) {

           if ($this->debug & 1) {

             printf("<b>clear_var:</b> (with array) <b>%s</b><br" . XHTML . ">\n", $v);

           }

           $this->set_var($v, '');

         }

       }

     }

   }

  /******************************************************************************

   * This functions unsets a variable completely.

   *

   * It may be called with either a varname as a string or an array with the 

   * values being the varnames to be cleared.

   *

   * The function removes the variable from the $varkeys and $varvals hashes.

   * It is not necessary for a variable to exist in these hashes before calling

   * this function.

   *

   *

   * usage: unset_var(string $varname)

   * or

   * usage: unset_var(array $varname = (string $varname))

   *

   * @param     $varname      either a string containing a varname or an array of varnames.

   * @access    public

   * @return    void

   */

   function unset_var($varname) {

     if (!is_array($varname)) {

       if (!empty($varname)) {

         if ($this->debug & 1) {

           printf("<b>unset_var:</b> (with scalar) <b>%s</b><br" . XHTML . ">\n", $varname);

         }

         unset($this->varvals[$varname]);

       }

     } else {

       foreach ($varname as $v) {

         if (!empty($v)) {

           if ($this->debug & 1) {

             printf("<b>unset_var:</b> (with array) <b>%s</b><br" . XHTML . ">\n", $v);

           }

           unset($this->varvals[$v]);

         }

       }

     }

   }

  /******************************************************************************

   * This function fills in all the variables contained within the variable named

   * $varname. The resulting value is returned as the function result and the

   * original value of the variable varname is not changed. The resulting string

   * is not "finished", that is, the unresolved variable name policy has not been

   * applied yet.

   *

   * Returns: the value of the variable $varname with all variables substituted.

   *

   * usage: subst(string $varname)

   *

   * @param     $varname      the name of the variable within which variables are to be substituted

   * @access    public

   * @return    string

   */

   function subst($varname) {

     if ($this->debug & 4) {

       echo "<p><b>subst:</b> varname = $varname</p>\n";

     }

     if (!$this->loadfile($varname)) {

       $this->halt("subst: unable to load $varname.");

       return false;

     }

 	$varkeys = array_map(

 		create_function('$a', 'return "{" . $a . "}";'),

 		array_keys($this->varvals)

 	);

     $str = $this->get_var($varname);

     $str = str_replace($varkeys, array_values($this->varvals), $str);

     return $str;

   }

  /******************************************************************************

   * This is shorthand for print $this->subst($varname). See subst for further

   * details.

   *

   * Returns: always returns false.

   *

   * usage: psubst(string $varname)

   *

   * @param     $varname      the name of the variable within which variables are to be substituted

   * @access    public

   * @return    false

   * @see       subst

   */

   function psubst($varname) {

     if ($this->debug & 4) {

       echo "<p><b>psubst:</b> varname = $varname</p>\n";

     }

     print $this->subst($varname);

     return false;

   }

  /******************************************************************************

   * The function substitutes the values of all defined variables in the variable

   * named $varname and stores or appends the result in the variable named $target.

   *

   * It may be called with either a target and a varname as two strings or a

   * target as a string and an array of variable names in varname.

   *

   * The function inserts the new value of the variable into the $varvals hashes.

   * It is not necessary for a variable to exist in these hashes before calling

   * this function.

   *

   * An optional third parameter allows the value for each varname to be appended

   * to the existing target variable instead of replacing it. The default is to

   * replace.

   *

   * If $target and $varname are both strings, the substituted value of the

   * variable $varname is inserted into or appended to $target.

   *

   * If $handle is an array of variable names the variables named by $handle are

   * sequentially substituted and the result of each substitution step is

   * inserted into or appended to in $target. The resulting substitution is

   * available in the variable named by $target, as is each intermediate step

   * for the next $varname in sequence. Note that while it is possible, it

   * is only rarely desirable to call this function with an array of varnames

   * and with $append = true. This append feature was introduced after the 7.2d

   * release.

   *

   * Returns: the last value assigned to $target.

   *

   * usage: parse(string $target, string $varname, [boolean $append])

   * or

   * usage: parse(string $target, array $varname = (string $varname), [boolean $append])

   *

   * @param     $target      a string containing the name of the variable into which substituted $varnames are to be stored

   * @param     $varname     if a string, the name the name of the variable to substitute or if an array a list of variables to be substituted

   * @param     $append      if true, the substituted variables are appended to $target otherwise the existing value of $target is replaced

   * @access    public

   * @return    string

   * @see       subst

   */

   function parse($target, $varname, $append = false) {

     if (!is_array($varname)) {

       if ($this->debug & 4) {

         echo "<p><b>parse:</b> (with scalar) target = $target, varname = $varname, append = $append</p>\n";

       }

       $str = $this->subst($varname);

       if ($append) {

         $this->set_var($target, $this->get_var($target) . $str);

       } else {

         $this->set_var($target, $str);

       }

     } else {

       foreach ($varname as $i => $v) {

         if ($this->debug & 4) {

           echo "<p><b>parse:</b> (with array) target = $target, i = $i, varname = $v, append = $append</p>\n";

         }

         $str = $this->subst($v);

         if ($append) {

           $this->set_var($target, $this->get_var($target) . $str);

         } else {

           $this->set_var($target, $str);

         }

       }

     }

     if ($this->debug & 4) {

       echo "<p><b>parse:</b> completed</p>\n";

     }

     return $str;

   }

  /******************************************************************************

   * This is shorthand for print $this->parse(...) and is functionally identical.

   * See parse for further details.

   *

   * Returns: always returns false.

   *

   * usage: pparse(string $target, string $varname, [boolean $append])

   * or

   * usage: pparse(string $target, array $varname = (string $varname), [boolean $append])

   *

   * @param     $target      a string containing the name of the variable into which substituted $varnames are to be stored

   * @param     $varname     if a string, the name the name of the variable to substitute or if an array a list of variables to be substituted

   * @param     $append      if true, the substituted variables are appended to $target otherwise the existing value of $target is replaced

   * @access    public

   * @return    false

   * @see       parse

   */

   function pparse($target, $varname, $append = false) {

     if ($this->debug & 4) {

       echo "<p><b>pparse:</b> passing parameters to parse...</p>\n";

     }

     print $this->finish($this->parse($target, $varname, $append));

     return false;

   }

  /******************************************************************************

   * This function returns an associative array of all defined variables with the

   * name as the key and the value of the variable as the value.

   *

   * This is mostly useful for debugging. Also note that $this->debug can be used

   * to echo all variable assignments as they occur and to trace execution.

   *

   * Returns: a hash of all defined variable values keyed by their names.

   *

   * usage: get_vars()

   *

   * @access    public

   * @return    array

   * @see       $debug

   */

   function get_vars() {

     if ($this->debug & 4) {

       echo "<p><b>get_vars:</b> constructing array of vars...</p>\n";

     }

     return $this->varvals;

   }

  /******************************************************************************

   * This function returns the value of the variable named by $varname.

   * If $varname references a file and that file has not been loaded yet, the

   * variable will be reported as empty.

   *

   * When called with an array of variable names this function will return a a

   * hash of variable values keyed by their names.

   *

   * Returns: a string or an array containing the value of $varname.

   *

   * usage: get_var(string $varname)

   * or

   * usage: get_var(array $varname)

   *

   * @param     $varname     if a string, the name the name of the variable to get the value of, or if an array a list of variables to return the value of

   * @access    public

   * @return    string or array

   */

   function get_var($varname) {

     if (!is_array($varname)) {

       if (isset($this->varvals[$varname])) {

         $str = $this->varvals[$varname];

       } else {

         $str = '';

       }

       if ($this->debug & 2) {

         printf ("<b>get_var</b> (with scalar) <b>%s</b> = '%s'<br" . XHTML . ">\n", $varname, htmlentities($str));

       }

       return $str;

     } else {

       foreach ($varname as $v) {

         if (isset($this->varvals[$v])) {

           $str = $this->varvals[$v];

         } else {

           $str = '';

         }

         if ($this->debug & 2) {

           printf ("<b>get_var:</b> (with array) <b>%s</b> = '%s'<br" . XHTML . ">\n", $v, htmlentities($str));

         }

         $result[$v] = $str;

       }

       return $result;

     }

   }

  /******************************************************************************

   * This function returns a hash of unresolved variable names in $varname, keyed

   * by their names (that is, the hash has the form $a[$name] = $name).

   *

   * Returns: a hash of varname/varname pairs or false on error.

   *

   * usage: get_undefined(string $varname)

   *

   * @param     $varname     a string containing the name the name of the variable to scan for unresolved variables

   * @access    public

   * @return    array

   */

   function get_undefined($varname) {

     if ($this->debug & 4) {

       echo "<p><b>get_undefined:</b> varname = $varname</p>\n";

     }

     if (!$this->loadfile($varname)) {

       $this->halt("get_undefined: unable to load $varname.");

       return false;

     }

     preg_match_all('/{([^ \t\r\n}]+)}/', $this->get_var($varname), $m);

     $m = $m[1];

     if (!is_array($m)) {

       return false;

     }

     foreach ($m as $v) {

       if (!array_key_exists($v, $this->varvals)) {

         if ($this->debug & 4) {

          echo "<p><b>get_undefined:</b> undefined: $v</p>\n";

         }

         $result[$v] = $v;

       }

     }

     if (count($result)) {

       return $result;

     } else {

       return false;

     }

   }

  /******************************************************************************

   * This function returns the finished version of $str. That is, the policy

   * regarding unresolved variable names will be applied to $str.

   *

   * Returns: a finished string derived from $str and $this->unknowns.

   *

   * usage: finish(string $str)

   *

   * @param     $str         a string to which to apply the unresolved variable policy

   * @access    public

   * @return    string

   * @see       set_unknowns

   */

   function finish($str) {

     switch ($this->unknowns) {

       case 'keep':

       break;

       case 'remove':

         $str = preg_replace('/{[^ \t\r\n}]+}/', '', $str);

       break;

       case 'comment':

         $str = preg_replace('/{([^ \t\r\n}]+)}/', "<!-- Template variable \\1 undefined -->", $str);

       break;

     }

     return $str;

   }

  /******************************************************************************

   * This function prints the finished version of the value of the variable named

   * by $varname. That is, the policy regarding unresolved variable names will be

   * applied to the variable $varname then it will be printed.

   *

   * usage: p(string $varname)

   *

   * @param     $varname     a string containing the name of the variable to finish and print

   * @access    public

   * @return    void

   * @see       set_unknowns

   * @see       finish

   */

   function p($varname) {

     print $this->finish($this->get_var($varname));

   }

  /******************************************************************************

   * This function returns the finished version of the value of the variable named

   * by $varname. That is, the policy regarding unresolved variable names will be

   * applied to the variable $varname and the result returned.

   *

   * Returns: a finished string derived from the variable $varname.

   *

   * usage: get(string $varname)

   *

   * @param     $varname     a string containing the name of the variable to finish

   * @access    public

   * @return    void

   * @see       set_unknowns

   * @see       finish

   */

   function get($varname) {

     return $this->finish($this->get_var($varname));

   }

  /******************************************************************************

   * When called with a relative pathname, this function will return the pathname

   * with $this->root prepended. Absolute pathnames are returned unchanged.

   *

   * Returns: a string containing an absolute pathname.

   *

   * usage: filename(string $filename)

   *

   * @param     $filename    a string containing a filename

   * @access    private

   * @return    string

   * @see       set_root

   */

   function filename($filename) {

     if ($this->debug & 4) {

       echo "<p><b>filename:</b> filename = $filename</p>\n";

     }

     // Test if file exist and add physical path as 2nd test

     if (!file_exists($filename)) {

         // Try appending file to template root

         $filename = $this->root.'/'.$filename;

         if (!file_exists($filename)) {

             $this->halt("filename: file $filename does not exist.");

         }

     }

     return $filename;

   }

  /******************************************************************************

   * If a variable's value is undefined and the variable has a filename stored in

   * $this->file[$varname] then the backing file will be loaded and the file's

   * contents will be assigned as the variable's value.

   *

   * Note that the behaviour of this function changed slightly after the 7.2d

   * release. Where previously a variable was reloaded from file if the value

   * was empty, now this is not done. This allows a variable to be loaded then

   * set to "", and also prevents attempts to load empty variables. Files are

   * now only loaded if $this->varvals[$varname] is unset.

   *

   * Returns: true on success, false on error.

   *

   * usage: loadfile(string $varname)

   *

   * @param     $varname    a string containing the name of a variable to load

   * @access    private

   * @return    boolean

   * @see       set_file

   */

   function loadfile($varname) {

     if ($this->debug & 4) {

       echo "<p><b>loadfile:</b> varname = $varname</p>\n";

     }

     if (!isset($this->file[$varname])) {

       // $varname does not reference a file so return

       if ($this->debug & 4) {

         echo "<p><b>loadfile:</b> varname $varname does not reference a file</p>\n";

       }

       return true;

     }

     if (isset($this->varvals[$varname])) {

       // will only be unset if varname was created with set_file and has never been loaded

       // $varname has already been loaded so return

       if ($this->debug & 4) {

         echo "<p><b>loadfile:</b> varname $varname is already loaded</p>\n";

       }

       return true;

     }

     $filename = $this->file[$varname];

     $str = @file_get_contents($filename);

     if (empty($str)) {

       $this->halt("loadfile: While loading $varname, $filename does not exist or is empty.");

       return false;

     }

     if ($this->debug & 4) {

       printf("<b>loadfile:</b> loaded $filename into $varname<br" . XHTML . ">\n");

     }

     $this->set_var($varname, $str);

     return true;

   }

  /******************************************************************************

   * This function is called whenever an error occurs and will handle the error

   * according to the policy defined in $this->halt_on_error. Additionally the

   * error message will be saved in $this->last_error.

   *

   * Returns: always returns false.

   *

   * usage: halt(string $msg)

   *

   * @param     $msg         a string containing an error message

   * @access    private

   * @return    void

   * @see       $halt_on_error

   */

   function halt($msg) {

     $this->last_error = $msg;

     if ($this->halt_on_error != 'no') {

       $this->haltmsg($msg);

     }

     /* we won't be coming back from haltmsg() in that case anyway

     if ($this->halt_on_error == 'yes') {

       die("<b>Halted.</b>");

     }

     */

     return false;

   }

  /******************************************************************************

   * This function prints an error message.

   * It can be overridden by your subclass of Template. It will be called with an

   * error message to display.

   *

   * usage: haltmsg(string $msg)

   *

   * @param     $msg         a string containing the error message to display

   * @access    public

   * @return    void

   * @see       halt

   */

   function haltmsg($msg) {

     if ($this->halt_on_error == 'yes') {

       trigger_error(sprintf("Template Error: %s", $msg));

     } else {

       printf("<b>Template Error:</b> %s<br" . XHTML . ">\n", $msg);

     }

   }

 }

 ?>