static void

ASP Valid-o-matic

Generate the validators for standard SQLServer datatypes (MSDN SQLServer-.Net datatype translation)

Change IDs and ControlToValidate (plus errormessages if required). NB bigint is a Currency type for validation purposes; int is the same so uses compareValidator instead of a rangeValidator.

• Remember Page.Validate() is called AFTER Page.Load (and not if control.CausesValidation=false).
• Currency type doesn't work with currency symbol. Beware when binding:
  Text='<%# Bind("Money", "{0:C}") %>' will not validate! (even with new CultureInvariant flag)
• Default Display="Static" which hides the message (or asterisk) with visibility (vertical alignment problems)- use Dynamic or None with a ValidationSummary
• To validate user and custom controls, add ValidationPropertyAttribute("valueproperty")
• ASP 2- Putting sets of controls into ValidationGroups is useful.
• See also Business Validation class for server side "business" errors

Highlight on error

Version 1: (Very) basic. To change the control dynamically, add (clientside) onchange function pointing to the control and validation id / clientID (in the latter case, inject via ScriptManager)

function MyFieldOnChange() {
   // Do nothing if client validation is not active
   if (typeof(Page_Validators) == "undefined")  return;
   // Change the color of the label
   MyField.style.color = MyFieldValidator.isvalid ? "Black" : "Red";
}

Version 2: Asp Ajax methods. The pageLoad initialization uses asp ajax methods ($addhandler == addEvent, $get == document.getElementById) but you can also use onchange="showIfError(this)".

function pageLoad() {
	if($addhandler) { //or your addEvent
		for (var i = 0; i < Page_Validators.length; i++) {  
		  var v = Page_Validators[i];
		  var id = v.controltovalidate;
		  var ctl= $get(id);
		  //if is textbox, monitor the change event
		  if(obj.type && (obj.type == 'text' || obj.type == 'textarea')) {
			  $addhandler(ctl, "change", showIfError);
		  }
		 }
	}
}

function showIfError(obj) {
	if(!checkValidators(obj.id) && obj.className.indexOf(" error") == -1)
		obj.className+= " error";
	else
		obj.className = new String(obj.className).replace(new RegExp("(?:^|\\s+)error(?:\\s+|$)", "g"), '');
}

function checkValidators(id) {
	for (var i = 0; i < Page_Validators.length; i++) {  
	  var v = Page_Validators[i];
	  if(v.controltovalidate == id) { //validate just this field
		ValidatorValidate(v); //force a validation
		if (v.isvalid == false) return false; //not valid
	   }
	}
	return true;
}

Version 3: JQuery. Here's a slightly more evolved JQuery script, which survives postbacks and sets the control with a class of "error".

$(document).ready(function() {
    if (self.ValidatorUpdateDisplay) {
        BaseValidatorUpdateDisplay = ValidatorUpdateDisplay;
        ValidatorUpdateDisplay = function(val) {
            BaseValidatorUpdateDisplay(val);
            $(function() {
                var errorCssClass = 'error';
                var ctl = document.getElementById(val.controltovalidate);
                if (ctl == null)
                    return;
                var vals;
                if (!ctl.Validators)
                    return;
                var vals = ctl.Validators;
                var showerror = false;
                for (var i = 0; i < vals.length; i++) {
                    if (!vals[i].isvalid) {
                        showerror = true;
                        break;
                    }
                }
                if (showerror) {
                    $(ctl).addClass(errorCssClass);
                }
                else {
                    $(ctl).removeClass(errorCssClass);
                }
            });
        }
    }

    //loop thru Page_Validators
    if (self.Page_Validators)
        return;
    var i, val;
    for (i = 0; i < Page_Validators.length; i++) {
        val = Page_Validators[i];
        if (!val.isvalid && val.controltovalidate.length > 0) {
            var ctl = document.getElementById(val.controltovalidate);
            if (ctl != null) {
                $(ctl).addClass('error');
            }
        }
    }
});