tailieunhanh - JavaScript Bible, Gold Edition part 141

JavaScript Bible, Gold Edition part 141. This book will bring programmers and non-technical professionals, including casual programmers and scripters, painlessly up to speed on all aspects of mastering JavaScript. Key topics include programming fundamentals, JavaScript language elements and how to use them effectively, and how to easily and efficiently add powerful new functionality to HTML documents and Java applets. | 1248 Part V Putting JavaScript to Work value code about the content of the signed items at the instant they were signed. In the case of a single page containing signed scripts the JAR file contains only the certificate and hash values of the signed scripts within the document. If the document links in an external .js script library file that library file is also packaged in the JAR file. Thus a page with signed scripts occupies space on the server for the HTML file and its companion JAR file. The SignTool program combines the JAR Packager with the script signing functions originally a separate program called . Follow links on the SignTool download page to the latest instructions on packaging and signing your finished files from the command line there is no GUI for this tool . But before you reach that point you need to compose your pages in a way that the security mechanism can protect your scripts. Preparing scripts for signing Signifying which items in a page are script items that require signing is up to the page author. It is important to remember that if you want to sign even one script element in a document every script in the document must be signed. By document I mean an object model document. Because the content of an NN4-only LAYER tag exists in its own document you don t have to sign its scripts if they don t require it nor communicate with the signed scripts in the main document. The first concept you have to master is recognizing what a script is. For signing purposes a script is more than just the set of statements between a SCRIPT and SCRIPT tag boundary. An event handler even one that calls a function living in a SCRIPT tag is also a script that needs signing. So too is a JavaScript entity used to supply a value to an HTML tag attribute. Each one of these items is a script as far as script signing is concerned. Your job is to mark up the file with special tag attributes that do two things 1 help SignTool know what items to sign in a file