WB 2.08.x

<?php

// $Id$

/*

 * Session Management for PHP3

 *

 * (C) Copyright 1999-2000 NetUSE GmbH

 *                    Kristian Koehntopp

 *

 * $Id$

 *

 */

/*

 * 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)

 * parse uses get_var to obtain return value (Jordi via SF)

 * set_block reports an error if the block could not be extracted (rha)

 * filename is now windows-pathname aware (krabu @ SF)

 *

 *

 * Changes in functionality which go beyond bug fixes:

 *

 * added ability for filename comments to be output (from phplib-users layne)

 * 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;

 /**

  * Determines whether Template outputs filename comments.

  * false = no filename outputs

  * true = HTML comments (e.g. <!-- START FILE $filename -->) placed in output

  *

  * @var       int

  * @access    public

  */

  var $filename_comments = false;

 /**

  * Determines the regular expression used to find unknown variable tags.

  * "loose"  = traditional match all curly braces with no whitespace between

  * "strict" = adopts PHP's variable naming rules

  *              ("loose" has a nasty habit of deleting JavaScript RegEx components)

  *              (should future major version releases of PHPLib default this "strict"?)

  *

  * @var       string

  * @access    public

  */

  var $unknown_regexp = "loose";

 /**

  * 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 regular expressions for themselves.

  * $varkeys[varname] = "/varname/"

  *

  * @var       array

  * @access    private

  * @see       set_var

  */

  var $varkeys  = 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(ereg('/$', $root)) {

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

    }

    if ($this->debug & 4) {

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

    }

    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 {

      reset($varname);

      while (list($v, $f) = each($varname)) {

        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 varkeys and 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);

/* workaround to avoid problems with some WB files/modules (e.g. massmail)

    if (!isset($m[1][0])) {

      $this->halt("set_block: unable to set block $varname.");

      return false;

    }

*/

    $str = preg_replace($reg, "{" . $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 $varkeys and

  * $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>\n", $varname, htmlentities($value));

        }

        $this->varkeys[$varname] = "/".$this->varname($varname)."/";

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

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

        } else {

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

        }

      }

    } else {

      reset($varname);

      while (list($k, $v) = each($varname)) {

        if (!empty($k)) {

          if ($this->debug & 1) {

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

          }

          $this->varkeys[$k] = "/".$this->varname($k)."/";

          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 $varkeys and $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>\n", $varname);

        }

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

      }

    } else {

      reset($varname);

      while (list($k, $v) = each($varname)) {

        if (!empty($v)) {

          if ($this->debug & 1) {

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

        }

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

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

      }

    } else {

      reset($varname);

      while (list($k, $v) = each($varname)) {

        if (!empty($v)) {

          if ($this->debug & 1) {

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

          }

          unset($this->varkeys[$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) {

    $varvals_quoted = array();

    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;

    }

    // quote the replacement strings to prevent bogus stripping of special chars

    reset($this->varvals);

    while (list($k, $v) = each($this->varvals)) {

      $varvals_quoted[$k] = preg_replace(array('/\\\\/', '/\$/'), array('\\\\\\\\', '\\\\$'), $v);

    }

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

    $str = preg_replace($this->varkeys, $varvals_quoted, $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 $varkeys and

  * $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 {

      reset($varname);

      while (list($i, $v) = each($varname)) {

        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 $this->get_var($target);

  }

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

  * 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, $clear = true) { // added $clear: whether to delete undefined vars or not (needed for wb-module code) - thorn

    if ($this->debug & 4) {

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

    }

		if(!$clear) {

			$unknowns = $this->unknowns;

			$this->set_unknowns('keep');

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

			$this->set_unknowns($unknowns);

		} else {

			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";

    }

    reset($this->varkeys);

    while (list($k, $v) = each($this->varkeys)) {

      $result[$k] = $this->get_var($k);

    }

    return $result;

  }

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

  * 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>\n", $varname, htmlentities($str));

      }

      return $str;

    } else {

      reset($varname);

      while (list($k, $v) = each($varname)) {

        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>\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(

        (("loose" == $this->unknown_regexp) ? "/{([^ \t\r\n}]+)}/" : "/{([_a-zA-Z]\\w+)}/"),

        $this->get_var($varname),

        $m);

    $m = $m[1];

    if (!is_array($m)) {

      return false;

    }

    reset($m);

    while (list($k, $v) = each($m)) {

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

        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(

            (("loose" == $this->unknown_regexp) ? "/{([^ \t\r\n}]+)}/" : "/{([_a-zA-Z]\\w+)}/"),

            "",

            $str);

      break;

      case "comment":

        $str = preg_replace(

             (("loose" == $this->unknown_regexp) ? "/{([^ \t\r\n}]+)}/" : "/{([_a-zA-Z]\\w+)}/"),

            "<!-- 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";

    }

    if (substr($filename, 0, 1) != "/" 

       && substr($filename, 0, 1) != "\\"

       && substr($filename, 1, 2) != ":\\"

       && substr($filename, 1, 2) != ":/"

    ) {

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

    }

    if (!file_exists($filename)) {

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

    }

    return $filename;

  }

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

  * This function will construct a regexp for a given variable name with any

  * special chars quoted.

  *

  * Returns: a string containing an escaped variable name.

  *

  * usage: varname(string $varname)

  *

  * @param     $varname    a string containing a variable name

  * @access    private

  * @return    string

  */

  function varname($varname) {

    return preg_quote("{" . $varname . "}");

  }

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

  * 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];

    /* use @file here to avoid leaking filesystem information if there is an error */

    $str = implode("", @file($filename));

    if (empty($str)) {

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

      return false;

    }

    if ($this->filename_comments) {

      $str = "<!-- START FILE $filename -->\n$str<!-- END FILE $filename -->\n";

    }

    if ($this->debug & 4) {

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

    }

    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) {

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

  }

}

?>