$.id = function(id){
  return document.getElementById(id);
}

$.fn.dbg = function(obj) {
  var buf = '';
  var o = obj || this;
  if (o) {
    for (var i in o) {
      if ((o[i] instanceof Function)
       || (o[i] == null)
       || (i.toUpperCase() == i)) continue;
      buf += i + '=' + o[i] + ', ';
    }
  } else buf = 'Null Object';
//  log(buf);,
  alert(buf);
  return o;
}

log = function(message) {
  if (! _log_timeout)
    _log_timeout = window.setTimeout(dump_log, 1000);
  _log_messages.push(message);
  function dump_log() {
    var message = '';
    for (var i = 0; i < _log_messages.length; i++)
      message += _log_messages[i] + '\n';
    alert(message);
    _log_timeout = null;
    delete _log_messages;
    _log_messages = new Array();
  }
}
_log_messages = new Array();
_log_timeout = null;

$.fn.link = function(target, callback) {
  this.click(function(e){
    e.preventDefault();
    $(this.rel || target).load(this.href || "", null, callback);
  });
  return this;
};

/**
 * Initial frontend function to submit form variables. This function
 * is for registering coordinates, in the case of an image being used
 * as the submit element, and sets up an event to listen and wait for
 * a form submit click. It then calls any following chained functions
 * to actually gather the variables and submit them.
 *
 * Usage examples, when used with getForm().putForm():
 *
 * 1. Just eval the results returned from the backend.
 *    $('#form-id').form();
 *
 * 2. Render backend results directly to target ID (expects (x)HTML).
 *    $('#form-id').form('#target-id');
 *
 * 3. Submit to backend URL (form action) then call this function.
 *    $('#form-id').form(post_callback);
 *
 * 4. Load target ID with backend results then call a function.
 *    $('#form-id').form('#target-id', null, post_callback);
 *
 * 5. Call a browser function (for validation) and then (optionally)
 *    load server results to target ID.
 *    $('#form-id').form('#target-id', pre_callback);
 *
 * 6. Call validation function first then load server results to
 *    target ID and then also call a browser function.
 *    $('#form-id').form('#target-id', pre_callback, post_callback);
 *
 * @param target   arg for the target id element to render
 * @param pre_cb   callback function before submission
 * @param post_cb  callback after any results are returned
 * @return         "this" object
 * @see            getForm(), putForm()
 * @author         Mark Constable (markc@renta.net)
 * @author         G. vd Hoven, Mike Alsup, Sam Collet
 * @version        20060606
 */
$.fn.form = function(target, pre_cb, post_cb) {
  $('input[@type="submit"],input[@type="image"]', this)
  .click(function(ev){
    this.form.clicked = this;
    if (ev.offsetX != undefined) {
      this.form.clicked_x = ev.offsetX;
      this.form.clicked_y = ev.offsetY;
    } else {
      this.form.clicked_x = ev.pageX - this.offsetLeft;
      this.form.clicked_y = ev.pageY - this.offsetTop;
    }
  });
  this.submit(function(e){
    e.preventDefault();
    $(this).getForm().putForm(target, pre_cb, post_cb);
    return this;
  });
};

/**
 * This function gathers form element variables into an array that
 * is embedded into the current "this" variable as "this.vars". It
 * is normally used in conjunction with form() and putForm() but can
 * be used standalone as long as an image is not used for submission.
 *
 * Standalone usage examples:
 *
 * 1. Gather form vars and return array to LHS variable.
 *    var myform = $('#form-id').getForm();
 *
 * 2. Provide a serialized URL-ready string (after 1. above).
 *    var mystring = $.param(myform.vars);
 *
 * 3. Gather form vars and send to RHS plugin via "this.vars".
 *    $('#form-id').getForm().some_other_plugin();
 *
 * @return         "this" object
 * @see            form(), putForm()
 * @author         Mark Constable (markc@renta.net)
 * @author         G. vd Hoven, Mike Alsup, Sam Collet
 * @version        20060606
 */
$.fn.getForm = function() {
  var a = [];
  var ok = {INPUT:true, TEXTAREA:true, OPTION:true};
  $('*', this).each(function() {
    if (this.disabled || this.type == 'reset'
     || (this.type == 'checkbox' && !this.checked)
     || (this.type == 'radio' && !this.checked)) return;

    if (this.type == 'submit' || this.type == 'image') {
      if (this.form.clicked != this) return;
      if (this.type == 'image') {
        if (this.form.clicked_x) {
          a.push({name: this.name+'_x', value: this.form.clicked_x});
          a.push({name: this.name+'_y', value: this.form.clicked_y});
          return;
        }
      }
    }
    if (!ok[this.nodeName.toUpperCase()]) return;
    var par = this.parentNode;
    var p = par.nodeName.toUpperCase();
    if ((p == 'SELECT' || p == 'OPTGROUP') && !this.selected) return;
    var n = this.name || par.name;
    if (!n && p == 'OPTGROUP' && (par = par.parentNode))
      n = par.name;
    if (n == undefined) return;
    a.push({name: n, value: this.value});
  });
  this.vars = a;
  return this;
}

/**
 * Final form submission plugin usually used in conjunction with
 * form() and getForm(). If a second argument is a valid function
 * then it will be called before the form vars are sent to the
 * backend. If this pre-submit function returns exactly "false"
 * then it will abort further processing otherwise the process
 * will continue according to the first and third arguments.
 *
 * If the first argument is a function, and it exists, then the form
 * values will be submitted and that callback function called. If
 * the first argument is a string value then the "load()" plugin
 * will be called which will populate the innerHTML of the indicated
 * element and a callback will be called if there is third argument.
 * If there are no arguments then the form values are submitted with
 * an additional variable (evaljs=1) which indicates to the backend
 * to to prepare the returned results for evaluation, ie; the result
 * needs to valid javascript all on a single line.
 *
 * Usage example:
 *
 * $.fn.myvars = function() {
 *   this.vars = [];
 *   for (var i in this) {
 *     if (this[i] instanceof Function || this[i] == null) continue;
 *     this.vars.push({name: i, value: this[i].length});
 *   }
 *   return this;
 * }
 *
 * precb = function(vars) {
 *   return confirm('Submit these values?\n\n'+$.param(vars));
 * }
 *
 * $('*').myvars().putForm('#mytarget',precb,null,'myhandler.php');
 *
 * @param target   arg for the target id element to render
 * @param pre_cb   callback function before submission
 * @param post_cb  callback after any results are returned
 * @param url      form action override
 * @param mth      form method override
 * @return         "this" object
 * @see            form(), getForm(), load(), xml()
 * @author         Mark Constable (markc@renta.net)
 * @author         G. vd Hoven, Mike Alsup, Sam Collet
 * @version        20060606
 */
$.fn.putForm = function(target, pre_cb, post_cb, url, mth) {
  var f = this.get(0);
  if (pre_cb && pre_cb.constructor == Function)
    if (pre_cb(this.vars) === false) return;
  var url = url || f.action || '';
  var mth = mth || f.method || 'POST';

  if (target && target.constructor == Function) {
    $.xml(mth, url, $.param(this.vars), target);
  } else if (target && target.constructor == String) {
    $(target).load(url, this.vars, post_cb);
  } else {
    this.vars.push({name: 'evaljs', value: 1});
    $.xml(mth, url, $.param(this.vars), function(r){
      eval(r.responseText);});
  }
  return this;
}

$.fn.changer = function(form, target, pre_cb, post_cb) {
  $(form).submit(function(e){
    e.preventDefault();
    return false;
  });
  this.change(function(e){
    e.preventDefault();
    $(form).getForm().putForm(target, pre_cb, post_cb);
    return this;
  });
}