Pocket PCs which run Windows CE 3.0, a version of Windows, is designed to be as compact and modular as possible. As a result, not all the features you've come to expect on a Windows PC are present-but a surprising number are available, including the Windows Script engines. JScript and Visual Basic Scripting Edition (VBScript) are available on all Pocket PCs to provide access to the script engines in applications such as Pocket Internet Explorer .
Pocket PC ships with a version of Internet Explorer, affectionately known as PIE (Pocket Internet Explorer). PIE has a bunch of interesting features, one of which is the ability to run script code in an HTML page. Because memory is at a premium on Pocket PCs, PIE allows only one script language, JScript, to be used in HTML pages. The JScript version that runs on Pocket PC is based on the JScript 3.0 code base.
Here are the few features available/not available in PIE.
|
Pocket Internet Explorer |
| HTML |
HTML3.2+ TABLE + FORM + FRAME |
| XHTML |
No |
| DynamicHTML |
No |
| Script |
WindowsCE JScript |
| CSS |
No |
| Image files |
GIF, JPEG, BMP, XBM |
| Security |
SSL 2.0/3.0, PCT, SGC |
| Cookie |
Yes |
| Multi-windows |
No |
| Bookmarks |
Yes |
| Page memo storage |
No |
| File upload |
No |
| External application helper |
No |
| Zoom |
No |
| Image save |
No |
| Auto-cruise |
No |
Using Script to Build Applications in HHT
To illustrate how we might use script to build applications on Pocket PCs, we have built some simple applications that use some of the JavaScript functionalities .One of the key challenges is how to get some form of dynamic content to the user without access to the rich object model that Internet Explorer on Windows provides.
Getting dynamic content in an HTML 3.2 world means that we have to rely on some old favorites,| in particular, alert and document. write. Luckily, both methods are supported in PIE, and they work pretty much identically to their counterparts in the desktop version of Internet Explorer. A word of caution, though: PIE is stricter about properly formatting your HTML page, so be sure that you have <HTML> and <BODY> tags in place.
PIE doesn't support the notion of being able to open new windows, so calling window. open in script code won't work. As a result, the only way we can get information to and from the user is via the alert and prompt methods. Using alert results in a slightly different title on the dialog box, and the OK button is on the title bar, in all Pocket PC applications. Apart from those differences, it's pretty much identical to the alert method in Internet Explorer.
Using Html/Web Controls to build applications in HHT
Certain JavaScript functionalities are not supported here as the PIE uses Jscript 3.0 code base and HTML 3.2. The type able dropdown list doesn't function properly in PIE and similarly the tree view web control behaves in a weird manner by posting back each time on clicking of expand or collapse button, which is different from the behavior of the tree view web control, executing on IE 6.0 on a PC. All these are due to the limited JavaScript support offered by PIE.
Conclusion:
The web application developed for Windows PC with DHTML,DOM and ASP.NET cannot be directly run on PDA/Pocket PC/HHT.
Possible solution is that PIE in mobile devices must be reinstalled with new version of Jscript which is not currently available (Only Jscript3.0), else the paid third party browsers like Net Access or Thunder Hawk etc which provide some support for JavaScript can be installed on mobile devices.