VDaemon PHP Library | VDaemon Extension | Table of Contents

VDaemon User Guide
How VDaemon works

VDaemon can perform server side and client side validation. Client side (javascript) validation is optional and can be turned off (default is on). VDaemon performs validation on the server even if the validation have already performed on the client. It helps prevent users from being able to bypass validation by disabling or changing the client script.

Server-Side Validation

When the user submits a form to the server, VDaemon code is invoked to review the user's input. If an error has occurred in any of the input controls, the page itself is set to an invalid state (validation failed) and user is redirected back to the form page with displayed error messages. If validation passed, user code specified on form processing page is invoked. Thus, VDaemon doesn't change HTML forms behavior except it always redirects visitor to the form page until visitor enters fully valid data. It allows easily incorporate VDaemon validation into existing web sites.

Client-Side Validation

If the user is working with browser that support DHTML and W3C DOM Level1, VDaemon can perform validation using client script. Because in this case immediate feedback is provided (without a round trip to the server), the user experience with the page is enhanced.

Under most circumstances, you do not have to make any changes to your page or to the validators to use client-side validation. VDaemon automatically detects if the browser supports DHTML and performs its checking accordingly. Client-side validation uses the same error display mechanism as server-side checking.

Currently client-side validation is tested for IE 6, Netscape 7, Opera 7.