// ----------------------------------------------------------------------
// Javascript form validation routines.
// Author: Stephen Poley
// Adaptation: haj
//
// Simple routines to quickly pick up obvious typos.
// All validation routines return true if executed by an older browser:
// in this case validation must be left to the server.
//
// Update Jun 2005: discovered that reason IE wasn't setting focus was
// due to an IE timing bug. Added 0.1 sec delay to fix.
//
// Update Oct 2005: minor tidy-up: unused parameter removed
//
// Update Jun 2006: minor improvements to variable names and layout
// ----------------------------------------------------------------------

var nbsp = 160;                // non-breaking space char
var node_text = 3;             // DOM text node-type
var emptyString = /^\s*$/ ;
var global_valfield;           // retain valfield for timer thread

function validateOnSubmit() {
  // var elem;
  var errs=0;

  // execute all element validations in reverse order, so focus gets
  // set to the first one in error.
  if (!validateComment (document.forms.commentform.comment, 'inf_comment')) errs += 1;
  if (!validateUrl   (document.forms.commentform.url,   'inf_url',  false)) errs += 1;
  if (!validateEmail (document.forms.commentform.email, 'inf_email', true)) errs += 1;
  if (!validateAuthor(document.forms.commentform.author,'inf_author'))      errs += 1;

  if (errs>1)  alert(errs+' Eingabefelder muessen vor dem Abschicken korrigiert werden');
  if (errs==1) alert('Ein Eingabefeld muss vor dem Abschicken korrigiert werden');

  return (errs==0);
};

// --------------------------------------------
//                  trim
// Trim leading/trailing whitespace off string
// --------------------------------------------

function trim(str)
{
  return str.replace(/^\s+|\s+$/g, '');
}


// --------------------------------------------
//                  setfocus
// Delayed focus setting to get around IE bug
// --------------------------------------------

function setFocusDelayed()
{
  global_valfield.focus();
}

function setfocus(valfield)
{
  // save valfield in global variable so value retained when routine exits
  global_valfield = valfield;
  setTimeout( 'setFocusDelayed()', 100 );
}


// --------------------------------------------
//                  msg
// Display warn/error message in HTML element.
// commonCheck routine must have previously been called
// --------------------------------------------

function msg(fld,     // id of element to display message in
             msgtype, // class to give element ("warn" or "error")
             message) // string to display
{
  // alert('fld = '+fld+', msgtype = '+msgtype+', message = '+message);
  // setting an empty string can give problems if later set to a
  // non-empty string, so ensure a space present. (For Mozilla and Opera one could
  // simply use a space, but IE demands something more, like a non-breaking space.)
  var dispmessage;
  if (emptyString.test(message))
    dispmessage = String.fromCharCode(nbsp);
  else
    dispmessage = message;

  var elem = document.getElementById(fld);
  elem.firstChild.nodeValue = dispmessage;

  elem.className = msgtype;   // set the CSS class to adjust appearance of message
}

// --------------------------------------------
//            commonCheck
// Common code for all validation routines to:
// (a) check for older / less-equipped browsers
// (b) check if empty fields are required
// Returns true (validation passed),
//         false (validation failed) or
//         proceed (don't know yet)
// --------------------------------------------

var proceed = 2;

function commonCheck    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var empty_text = "Fehler: Bitte fuell' das Eingabefeld aus";
  var original_text;

  switch (infofield) {
    case 'inf_author':
      original_text = 'Name (erforderlich)';
      break;
    case 'inf_email':
      original_text = 'E-mail (wird nicht veroeffentlicht) (erforderlich)';
      break;
    case 'inf_url':
      original_text = 'Webseite';
      break;
    case 'inf_comment':
      original_text = 'Kommentar (erforderlich)';
      break;
    default:
      original_text = '';
      break;
  }

  if (!document.getElementById)
    return true;  // not available on this browser - leave validation to the server
  var elem = document.getElementById(infofield);
  if (!elem.firstChild) return true;  // not available on this browser
  if (elem.firstChild.nodeType != node_text) return true;  // infofield is wrong type of node

  if (emptyString.test(valfield.value)) {
    if (required) {
      msg (infofield, "error", empty_text);
      setfocus(valfield);
      return false;
    }
    else {
      msg (infofield, "small_txt", original_text);   // OK
      return true;
    }
  }
  // alert('infofield = '+infofield+', original_text='+original_text);
  // msg (infofield, "small_txt", original_text);   // OK
  return proceed;
}

// --------------------------------------------
//            validateAuthor
// Validate if something has been entered
// Returns true if so
// --------------------------------------------

function validateAuthor(valfield,   // element to be validated
                        infofield ) // id of element to receive info/error msg
{
  var original_text = 'Name (erforderlich)';
  var stat = commonCheck (valfield, infofield, true);

  if (stat != proceed) return stat;

  msg (infofield, "small_txt", original_text);
  return true;
}

// --------------------------------------------
//               validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateEmail  (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var original_text = 'E-mail (wird nicht veroeffentlicht) (erforderlich)';
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;
  if (!email.test(tfld)) {
    msg (infofield, "error", "Fehler: E-mail-Adresse ist nicht gueltig");
    setfocus(valfield);
    return false;
  }

  var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/  ;
  if (!email2.test(tfld))
    msg (infofield, "warn", "E-mail-Adresse ist ungewoehnlich - klaere, ob sie korrekt ist");
  else
    msg (infofield, "small_txt", original_text);
  return true;
}


// --------------------------------------------
//            validateComment
// Validate comment textarea
// Returns true if so (and also if could not be executed because of old browser)
// Permits spaces, hyphens, brackets and leading +
// --------------------------------------------

function validateComment(valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var original_text = 'Kommentar (erforderlich)';
  var stat = commonCheck (valfield, infofield, true);

  if (stat != proceed) return stat;

  msg (infofield, "small_txt", original_text);
  return true;
}

// --------------------------------------------
//             validateUrl
// Validate entered URL
// Returns true if OK
// --------------------------------------------

function validateUrl    (valfield,   // element to be validated
                         infofield,  // id of element to receive info/error msg
                         required)   // true if required
{
  var stat = commonCheck (valfield, infofield, required);
  if (stat != proceed) return stat;

  var tfld = trim(valfield.value);
  var urlRE = /^http:\/\/[a-zA-z0-9\.\/]*$/
  if (!urlRE.test(tfld)) {
    msg (infofield, "error", "Fehler: Webseiten-Adresse ist nicht gueltig (muss mit 'http://' beginnen)");
    setfocus(valfield);
    return false;
  }

  return true;
}