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JavaScript calls

Even if someone downloads your code, it’s now impossible to reverse engineer or otherwise figure out.

All your JavaScript calls from within an HTML file can be used in the exact same way (meaning you

don’t have to worry about encoding your JavaScript calls; just make them as you would normally).

The downside to this technique is that it works only on Internet Explorer on Windows. After it is

encoded, the script is essentially useless to any other browsers on any other operating systems. If you

are sure that your only users are running IE on Windows (such as in a corporate Intranet), this may be

helpful to you. Otherwise it’s best to go with an obfuscating utility that works across all browsers.

Summary

In this chapter, you’ve learned about several issues relating to the deployment of JavaScript to a public

Web site or to a client via a Web application.

The first issue discussed was security. Various security issues, ranging from general concepts (such

as the Same Origin Policy) to browser-specific issues (like Mozilla’s signed scripts), were discussed.

JavaScript’s security limitations in regards to the BOM and the DOM were also covered.

Next, you learned how to optimize JavaScript code. The two ways to optimize JavaScript are to mini-

mize the size of the code (by removing extra white space and comments) and to reduce the time it takes

for the script to execute (by using common programming techniques). I discussed a variety of different

methods to achieve optimization, and I also introduced several utilities that can aid in the process.

The last topic discussed was intellectual property. Code obfuscation and encoding were introduced as

methods to prevent reverse engineering. You learned that obfuscation is a better solution for cross-

browser compatibility than using the Windows Script Encoder, which works only for Internet Explorer

on Windows. Ultimately, the method you use to protect your intellectual property is largely determined

by the Web solution you are developing.

You can learn more about the Microsoft Script Encoder at

http://msdn

.microsoft.com/library/default.asp?url=/library/en-us/script56/

html/seusingscriptencoder.asp

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Deployment Issues

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