formChecker object class v0.2

// shorthand for getElementById
function $lm(obj){
  if ( document.getElementById(obj) ) return document.getElementById(obj);
  else return false;
}

// object's first child with the given class
function firstChildofClass(p,cl) {
  if (!p || !p.childNodes.length)return;
  var ch = p.childNodes;
  for ( var i = 0; i < ch.length; i++ ){
    if (gotClass(ch[i],cl))return ch[i];
  }
  return;
}

// shorthand for firstChildOfClass
function $fc(p, cl){
  return firstChildofClass(p,cl);
}

function gotClass(obj,cl) {
    var r = new RegExp("\\b" + cl + "\\b", "i");
    var ob = ( typeof(obj) == "object" ) ? obj : $lm(obj);
    if ( ob && ob.className && ob.className.match(r) !== null ) return true;
    return false;
}

// object's all children with given class
function getChildElementsByClassName(obj,cl){
  var oc = ( obj != undefined ) ? obj.childNodes : document.body.childNodes;
  var ch = [];
  for ( var i = 0; i < oc.length; i++ ){
    if (gotClass(oc[i],cl)) ch.push(oc[i]);
  }
  return ch;
}

// shorthand for getChildElementsByClassName
function $cc(obj,cl){
  return getChildElementsByClassName(obj,cl);
}

// shorthand for parseFloat
function pf(n){return parseFloat(n);}

// set object's css style
function setStyle(obj,st,vl){
    var a = obj.style.cssText;
    obj.style.cssText = (a.length>0) ? a + ";" + st + ":" + vl : st + ":" + vl ;
}

// trim and compress spaces
String.prototype.clean = function(){
    return this.replace(/^(\s+)/g,"").replace(/(\s+)$/g , "").replace(/\s\s+/g , " ");
}

// add given class to object's className
function addClass(obj,c){
    obj.className = (obj.className.length > 0) ? obj.className + " " + c : c;
}

// remove given class from object's className
function removeClass(obj,c){
    var r = new RegExp("(\\b" + c + "\\b)", "gi");
    obj.className = obj.className.replace( r , " " ).clean();
}

/* formChecker class definition
 * parameters:
 * fm - the form to be verified
 * rule - form rules in JSON format
 * rule record (object) properties:
 * sbj - input class
 *      if the form contains more than one input of the same class, each one will be verified
 * fnc - verifier function (these are methods of the chk() object class)
 *      see functions for more details
 * prm - value to verify against
 *      can be a fixed value or a form elem value defined by class or id (css-like definitions -> ".myclass" or "#myid")
 *
 * usage:
 *      1) design your own checker functions into chk() class definition if necessary
 *      2) design your own rules
 *      3) design callback functions (init, success, failure, error)
 *      4) insert init code
 *
 *      for live example see my pastebin
 *
**/

function formChecker(fm,rule,cf,sf,ff,ef){

    if (!fm) return;

    this.fm = fm;       // form DOM object
    this.rule = rule;   // rule JSON object-list
    this.res = [];      // result array
    this.nof = 0;       // number of fails

    if ( cf == undefined || typeof cf != "function" )cf = null;
    if ( sf == undefined || typeof sf != "function" )sf = null;
    if ( ff == undefined || typeof ff != "function" )ff = null;
    if ( ef == undefined || typeof ef != "function" )ef = null;

    this.chk = function(){

        var r,val,lm,c,prm;

        // clear earlier results
        cf(this.fm);

        // rules
        for (var i in this.rule){

            r = this.rule[i];

            // check only if object exists
            if ( $fc(this.fm,r.sbj) ){

                // handle parameters
                // only try to find css-like object reference, if not number and not regexp
                // css-style DOM reference lookup with ".myclass" and "#myid"

                prm = r.prm;

                if ( isNaN(prm) && r.fnc != "rg" ){

                    // ".myclass"
                    if ( /^\.\w+$/i.test(prm) ){

                        var tst = true;
                        // only first object of the same class
                        if ( $fc( this.fm , prm.substr(1) ) )prm = $fc( this.fm , prm.substr(1) ).value;

                    }

                    // "#myid"
                    else if ( /^#\w+$/i.test(prm) ){

                        var tst = true;
                        if ( $lm( prm.substr(1) ) )prm = $lm( prm.substr(1) ).value;

                    }

                }

                // if there's more than one input of the same class, verify each
                lm = $cc(this.fm,r.sbj);
                for (var i = 0; i < lm.length; i++){

                    c = new chk(lm[i]);
                    try{

                        val = c.exec(r.fnc,prm);

                        // fail
                        if(!val){

                            ff(lm[i],r.msg);
                            this.nof++;

                        }

                        // success
                        else sf(lm[i],"");

                    } catch(er) {

                        // error
                        val = ef(er);

                    }

                    this.res.push(val);

                }

            }

        }

        return this.nof;

    }

}

function chk(obj){

    this.v = (obj.value) ? obj.value : obj.innerHTML;

    // numeric "equals"
    this.eq = function(b){
        if (pf(this.v) == pf(b))return true;
        return false;
    }

    // string equals ("exact")
    this.ex = function(b){
      if (this.v == b)return true;
      return false;
    }

    // numeric "lesser than"
    this.lt = function(b){
        if (pf(this.v) < pf(b))return true;
        return false;
    }

    // numeric "lesser or equals"
    this.le = function(b){
      if (pf(this.v) <= pf(b))return true;
        return false;
    }

    // numeric "greater than"
    this.gt = function(b){
      if (pf(this.v) > pf(b))return true;
        return false;
    }

    // numeric "greater or equals"
    this.ge = function(b){
      if (pf(this.v) >= pf(b))return true;
        return false;
    }

    // empty ?
    this.nn = function(){
        if (this.v.toString().length > 0)return true;
        return false;
    }

    // regexp pattern
    this.rg = function(b){
        var bb = new RegExp(b[0],b[1]);
        return bb.test(this.v);
    }

    this.exec = function(f, arg) {

        return this[f](arg);

    }

}