• ";


/// Functions

function s($var) {
/// returns $var with HTML characters (like "<", ">", etc.) properly quoted,

    if (empty($var)) {
        return "";
    }
    return htmlSpecialChars(stripslashes_safe($var));
}

function p($var) {
/// prints $var with HTML characters (like "<", ">", etc.) properly quoted,

    if (empty($var)) {
        echo "";
    }
    echo htmlSpecialChars(stripslashes_safe($var));
}

function nvl(&$var, $default="") {
/// if $var is undefined, return $default, otherwise return $var 

    return isset($var) ? $var : $default;
}

function strip_querystring($url) {
/// takes a URL and returns it without the querystring portion 

    if ($commapos = strpos($url, '?')) {
        return substr($url, 0, $commapos);
    } else {
        return $url;
    }
}

function get_referer() {
/// returns the URL of the HTTP_REFERER, less the querystring portion 

    return strip_querystring(nvl($_SERVER["HTTP_REFERER"]));
}


function me() {
/// returns the name of the current script, WITH the querystring portion.
/// this function is necessary because PHP_SELF and REQUEST_URI and SCRIPT_NAME
/// return different things depending on a lot of things like your OS, Web
/// server, and the way PHP is compiled (ie. as a CGI, module, ISAPI, etc.) 

    if (!empty($_SERVER["REQUEST_URI"])) {
        return $_SERVER["REQUEST_URI"];

    } else if (!empty($_SERVER["PHP_SELF"])) {
        if (!empty($_SERVER["QUERY_STRING"])) {
            return $_SERVER["PHP_SELF"]."?".$_SERVER["QUERY_STRING"];
        }
        return $_SERVER["PHP_SELF"];

    } else if (!empty($_SERVER["SCRIPT_NAME"])) {
        if (!empty($_SERVER["QUERY_STRING"])) {
            return $_SERVER["SCRIPT_NAME"]."?".$_SERVER["QUERY_STRING"];
        }
        return $_SERVER["SCRIPT_NAME"];

    } else {
        notify("Warning: Could not find any of these web server variables: \$REQUEST_URI, \$PHP_SELF or \$SCRIPT_NAME");
        return false;
    }
}


function qualified_me() {
/// like me() but returns a full URL 

    if (!empty($_SERVER["HTTP_HOST"])) {
        $hostname = $_SERVER["HTTP_HOST"];
    } else if (!empty($_ENV["HTTP_HOST"])) {
        $hostname = $_ENV["HTTP_HOST"];
    } else if (!empty($_ENV["SERVER_NAME"])) {
        $hostname = $_ENV["SERVER_NAME"];
    } else {
        notify("Warning: could not find the name of this server!");
        return false;
    }

    $protocol = (isset($_SERVER["HTTPS"]) and $_SERVER["HTTPS"] == "on") ? "https://" : "http://";
    $url_prefix = $protocol.$hostname;
    return $url_prefix . me();
}


function match_referer($goodreferer = "") {
/// returns true if the referer is the same as the goodreferer.  If
/// goodreferer is not specified, use qualified_me as the goodreferer 
    global $CFG;

    if (empty($CFG->secureforms)) {    // Don't bother checking referer
        return true;
    }

    if ($goodreferer == "nomatch") {   // Don't bother checking referer
        return true;
    }

    if (empty($goodreferer)) { 
        $goodreferer = qualified_me(); 
    }
    return $goodreferer == get_referer();
}

function data_submitted($url="") {
/// Used on most forms in Moodle to check for data
/// Returns the data as an object, if it's found.
/// This object can be used in foreach loops without
/// casting because it's cast to (array) automatically
/// 
/// Checks that submitted POST data exists, and also 
/// checks the referer against the given url (it uses 
/// the current page if none was specified.

    global $CFG;

    if (empty($_POST)) {
        return false;

    } else {
        if (match_referer($url)) {
            return (object)$_POST;
        } else {
            if ($CFG->debug > 10) {
                notice("The form did not come from this page! (referer = ".get_referer().")");
            }
            return false;
        }
    }
}

function stripslashes_safe($string) {
/// stripslashes() removes ALL backslashes even from strings 
/// so  C:\temp becomes C:temp  ... this isn't good.
/// The following should work as a fairly safe replacement 
/// to be called on quoted AND unquoted strings (to be sure)

    $string = str_replace("\\'", "'", $string);
    $string = str_replace('\\"', '"', $string);
    $string = str_replace('\\\\', '\\', $string);
    return $string;
}

function stri_replace($find, $replace, $string ) {
/// This does a search and replace, ignoring case
/// This function is only here because one doesn't exist yet in PHP
/// Unlike str_replace(), this only works on single values (not arrays)

    $parts = explode(strtolower($find), strtolower($string));

    $pos = 0;

    foreach ($parts as $key => $part) {
        $parts[$key] = substr($string, $pos, strlen($part));
        $pos += strlen($part) + strlen($find);
    }

    return (join($replace, $parts));
}

function read_template($filename, &$var) {
/// return a (big) string containing the contents of a template file with all
/// the variables interpolated.  all the variables must be in the $var[] array or
/// object (whatever you decide to use).
///
/// WARNING: do not use this on big files!! 

    $temp = str_replace("\\", "\\\\", implode(file($filename), ""));
    $temp = str_replace('"', '\"', $temp);
    eval("\$template = \"$temp\";");
    return $template;
}

function checked(&$var, $set_value = 1, $unset_value = 0) {
/// if variable is set, set it to the set_value otherwise set it to the
/// unset_value.  used to handle checkboxes when you are expecting them from
/// a form 

    if (empty($var)) {
        $var = $unset_value;
    } else {
        $var = $set_value;
    }
}

function frmchecked(&$var, $true_value = "checked", $false_value = "") {
/// prints the word "checked" if a variable is true, otherwise prints nothing,
/// used for printing the word "checked" in a checkbox form input 

    if ($var) {
        echo $true_value;
    } else {
        echo $false_value;
    }
}


function link_to_popup_window ($url, $name="popup", $linkname="click here", $height=400, $width=500, $title="Popup window") {
/// This will create a HTML link that will work on both 
/// Javascript and non-javascript browsers.
/// Relies on the Javascript function openpopup in javascript.php
/// $url must be relative to home page  eg /mod/survey/stuff.php

    global $CFG;

    echo "\n";
    echo "\n\n";

}

function close_window_button() {
/// Prints a simple button to close a window

    echo "
      ";
    echo "";
    echo "
      ";
}


function choose_from_menu ($options, $name, $selected="", $nothing="choose", $script="", $nothingvalue="0", $return=false) {
/// Given an array of value, creates a popup menu to be part of a form
/// $options["value"]["label"]
    
    if ($nothing == "choose") {
        $nothing = get_string("choose")."...";
    }

    if ($script) {
        $javascript = "onChange=\"$script\"";
    } else {
        $javascript = "";
    }

    $output = "\n";

    if ($nothing != "") {
        $output .= "   \n";
    }

    foreach ($options as $value => $label) {
        if (substr($label,0,1) == "-") {
            $output .= "