ActiveX Controls - Field Validation

ActiveX controls and VBScript are another technology that can be used to validate data entry at the client side. ActiveX was developed by Microsoft and it includes Server components, such as Active Server Pages (.asp), as well as client side components called ActiveX controls. This is the area of interest for this project.

ActiveX controls are similar to Java Applets. They can be invoked from HTML and parameters can be passed in to control their workings. Support for ActiveX controls is included in Microsoft's Internet Explorer browsers starting with version 3.0. A company called NCompass Labs developed a Netscape Plugin to support ActiveX but they have temporarily stopped distributing it due to bugs and technical changes with ActiveX controls.

There are many ActiveX controls, including several from Microsoft, that are already available and can be used as is. There are also 3rd parties who have developed special controls which can be purchased and you always have the option to develop your own controls.

Microsoft claims that a key advantage of ActiveX controls over Java Applets and Netscape plug-ins is that ActiveX controls can also be used in applications written in many programming languages, including all of the Microsoft programming and database languages.

A significant problem with ActiveX is that not all Browsers or Operating Systems support these controls which will limit it's acceptance by Users. Today, it is basically a Microsoft solution which requires Internet Explorer as your Browser.

ADVANTAGES:

Controls can be developed in several languages (including JAVA).
Greater and easier control over page layout and component placement.
Advanced features support exact object placement, object layering, and transparency effects.
Controls are "installed" by the Browser. Once a control is installed, it does not have to be downloaded again.
Some controls come pre-installed with the Browser.
Many ActiveX controls available from 3rd parties.
Automatic version change detection and download of new version.
You can use either VBScript or JavaScript to integrate the controls.
ActiveX Control Pad tool makes adding existing controls to HTML files fairly easy.

DISADVANTAGES:

Limited Browser support.
Limited Operating System support. (There is a UNIX version of Microsoft's Internet Explorer expected by year end.)
Developing you own controls is fairly complex.

ActiveX Control Pad

The ActiveX control pad comes with many controls that can be used to mimic traditional HTML forms or even better, to mimic existing GUIs such as Windows or Motif based interfaces. Some of the available controls are:

Checkbox	ComboBox	CommandButton
Frame	Image	Label
ListBox	MultiPage	OptionButton
ScrollBar	SpinButton	TabStrip
TextBox	ToggleButton

The following examples use these existing ActiveX controls from Microsoft. It is only useable with an ActiveX enabled Browser (Internet Explorer). You may need to install the Microsoft ActiveX Control Pad to get the controls that are used in the examples.

ActiveX Example 1

ActiveX Example 2

NOTE: You can use this link to get the ActiveX Control Pad.

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