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Error! No text of specified style in document. Warnings: . MSIE version 4 does not support the Netscape Navigator privilege model. Therefore scripts are always unprivileged. The MSIE security model is based on zones. This is a fairly coarse grained approach and simply allows scripts to be executed or not as a whole. The Netscape Navigator model allows access to be controlled object by object. . Being so closely related to the MSIE browser, the WebTV box also does not support signed scripts. See also: AuthentiCode, Code signing, Data-tainting, export, import, JellyScript, Requesting privileges, Same origin Web-references: http://developer.netscape.com/software/signedobj/ http://developer.netscape.com/library/documentation/signedobj/signtool/ Single line comment (Definition) A pair of slash characters (//) indicates single line comments. Single line comments are indicated by a pair of slash characters (//) and are completed by a line terminator. The pair of slash characters and everything following them to the end of the line is considered to be a comment. Comments are discarded during the interpretation phase of a line of script. A pair of slash characters would not behave as a comment delimiter if one of them were escaped with a backslash character or if they appeared inside a single or double quoted string literal. See also: Comment, Comment (//and /* … */), Line Cross-references: ECMA 262 edition 2 section 7.3 ECMA 262 edition 3 section 7.4 Wrox Instant JavaScript page 17 Slide() (Filter/transition) A transition effect with the appearance of one image sliding over another. Availability: JScript 5.5 Internet Explorer 5.5 Refer to: Filter Slide() 1931

Chapter number Signed scripts (Security related) A means of giving scripts a privilege to access secure content. Netscape Navigator allows scripts to have digital signatures attached to them. These signatures can control the level of privilege that a script is allowed to have in a web browser. This is ultimately under user control but if the user allows, the scripts can be secured at source. The signature combines the identity of the signatory and a checksum of the content. The content cannot be modified without invalidating the checksum and hence voiding the signature. It would be difficult to establish the exact security criteria beforehand, so Netscape Navigator forces scripts to request the privileges they need. Then, you can allow or deny the access which can be stored and mapped against the identity of the person signing the script. This means a security policy can gradually be established by training the browser to recognize and make decisions on access. Initially, no access is available but after some time, your browser preferences will contain a very sophisticated set of rules that govern the access to the secure values. To sign your scripts, you will need additional tools and utilities. These are available from Netscape and should form part of your publishing pipeline. An alternative is to serve your scripts separately from a secure server. Scripts served in this way will assumed to have been signed by the secure server itself. As a way round the inconvenience of signing scripts after every minor correction, you can sign the codebase of a script. This means you can establish a security setting for scripts from a specific web server. It is slightly less secure than signing a checksum but more convenient during development. It is recommended that proper signing be used; once the script changes are less frequent and the development process is complete, the scripts will be more stable and signing will be carried out less frequently. With some automation in the publishing work flow, you may be able to sign scripts as part of the releasing procedure that your developers employ. Your web page may contain more than one script. For signed script access control to work, all of the scripts on a page must be signed. If an unsigned script is present, it defeats the entire signing status of the whole page. Scripts can be signed by more than one person. Netscape Navigator will try and find the highest most complete coverage of the scripts in a page. Ideally it will find a particular signer who has signed all of the scripts. Other signers may have conferred a higher level of security but not on all of the scripts. The more complete coverage will prevail. Although these fairly strict same-signer policies apply to the scripts within a window, scripts in multiple windows may operate under a slightly relaxed policy. The “same signer” policy is a variation of the “same origin” policy. Different signers cause the browser to behave as if the pages were from different origins. Both scripts may have rights to request UniversalBrowserRead access which might work around the problem. Unsigned scripts have quite restricted access to window properties for windows that contain signed scripts. This means that untrusted and insecure scripts cannot access secure data by subverting an already trusted script. 1930

Error! No text of specified style in document. Refer to: Window.showModelessDialog() .shtm (File extension) Server-side processed HTML file. Refer to: File extensions .shtml (File extension) Server-side processed HTML file. Refer to: File extensions Side effect (Definition) The changes to the execution environment due to some code being executed. When functions are executed, they may alter some item in memory or cause some change to occur aside from simply returning a value. For example, a function may create an object and add it to a persistent array and return some value such as the number of elements in that array. The calling expression was not aware that the array was extended and simply received a numeric value as a result of evaluating the function. The side effect was that the array became longer by one element. See also: Expression, Script execution Sidebar object (Object/Navigator) A new object introduced with Netscape 6.0 to manage the left side navigation bar. Availability: JavaScript 1.5 Netscape 6.0 N myWindow.sidebar JavaScript syntax: N sidebar This is a new object which needs to be explored as we get to know the netscape Navigator 6.0 browser. It encapsulates the behavior and appearance of the sidebar frame on the left of the browser window. See also: Window.sidebar 1929

Chapter number showHelp() (Method) Displays the help window. Availability: JScript 3.0 Internet Explorer 4.0 IE myWindow.showHelp() JavaScript syntax: IE showHelp() Refer to: Window.showHelp() showModalDialog() (Method) An alias for the window.showModalDialog() method. JScript 3.0 Availability: Internet Explorer 4.0 Property/method value type: User defined JavaScript syntax: myWindow.showModalDialog(aURL, someArguments) IE showModalDialog(aURL, someArguments) aURL IE Argument list: A URL to load into the modal dialog someArguments Arguments to pass to the modal dialog Refer to: Window.showModalDialog() showModelessDialog() (Method) An alias for the window.showModelessDialog() method. Availability: JScript 5.0 Internet Explorer 5.0 Property/method value type: User defined IE myWindow.showModelessDialog(aURL, someArguments)JavaScript syntax: IE showModelessDialog(aURL, someArguments) aURL A URL to load into the modal dialog Argument list: someArguments Arguments to pass to the modal dialog 1928

Error! No text of specified style in document. Shift operator (Definition) Used to create a shift expression. Availability: Property/method value type: ECMAScript edition 2 Number primitive Shift operators convert their left operands to a 32-bit integer value and shift them according to their right operation. The operator determines the kind of shifting that is applied. Bitwise shift left (<<), Bitwise shift left then assign (<<=), Bitwise shift operator, Bitwise shift right (>>), Bitwise shift right and assign (>>=), Bitwise unsigned shift right (>>>), Bitwise unsigned shift right and assign (>>>=) See also: Cross-references: ECMA 262 edition 2 section 11.7 ECMA 262 edition 3 section 11.7 short (Reserved word) Reserved for future language enhancements. The inclusion of this reserved keyword in the ECMAScript standard suggests that future versions of ECMAScript may be more strongly typed. This keyword also represents a Java data type and the short keyword allows for the potential extension of JavaScript interfaces to access Java applet parameters and return values. See also: double, float, Integer, LiveConnect, long, Reserved word Cross-references: ECMA 262 edition 2 section 7.4.3 ECMA 262 edition 3 section 7.5.3 1927

Chapter number See also: Prototype Based Inheritance, Prototype chain, prototype property Cross-references: ECMA 262 edition 2 section 10.1.4 Shell Scripting with JavaScript (Definition) Unix command line tools written in JavaScript. Once you have a JavaScript interpreter installed on your system, possibly to provide a server-side or CGI handling mechanism, you can easily use it then to do the things you might previously have done in Perl, Tcl, Bourne, Korn or C-Shell. Not that you would necessarily choose JavaScript over the other alternatives but for some projects it might be better suited due to the kind of data you are manipulating or what you need to do to it. The main strength of the Unix environment is the way multiple scripting languages can be used at will and a project may be built from code that runs in many different environments and contexts. See also: CGI Driven JavaScript, Host environment, Platform, Server-side JavaScript Cross-references: Wrox Instant JavaScript page 5 Shift expression (Definition) Shifts the left value by an amount specified by the right value. Availability: Property/method value type: ECMAScript edition 2 Number primitive Bitwise shift operators convert their left operands to a 32-bit integer value and shift them according to their right operation. The operator determines the kind of shifting that is applied. See also: Bitwise shift operator, Expression Cross-references: ECMA 262 edition 2 section 11.7 ECMA 262 edition 3 section 11.7 1926

Error! No text of specified style in document. Refer to: Filter Shadow() Shallow copying (Definition) Copying object references and not the objects. See also: Array.toSource() Refer to: Copying objects Shared Property (Definition) A property contained in a prototype and shared between several instances. Availability: ECMAScript edition 2 You can create several objects and make them share a common ancestor. In a class-based object oriented world, this would be called sub-classing. Instantiating each one means it would inherit properties from its super-class, but objects of the same class in a real object oriented system do not share property values unless the static (class) factory method that instantiates them presets the same values as they are initialized. In JavaScript, because the prototype chain is used to inherit properties from parent objects and not parent classes, then objects will inherit property values unless they override them locally. If you are used to the class-based object oriented way of doing things, this can be quite distracting. Object prototype null A number object A number object An Object objectA string objectA string object String prototype Number prototype 1925

Chapter number setTimeout() (Method) A method for setting a one shot timer. Availability: JavaScript 1.0 JScript 1.0 Internet Explorer 3.02 Netscape 2.0 Opera 3.0 Property/method value type: Number primitive -myWindow.setTimeout(aSourceText, aWaitTime)JavaScript syntax: -setTimeout(aSourceText, aWaitTime) aSourceText Some valid JavaScript source text Argument list: aWaitTime A delay in milliseconds See also: Timer events, Window.setInterval(), Window.setTimeout() setZOptions() (Method) Defines the window stacking behaviour. Availability: JavaScript 1.2 Netscape 4.0 Property/method value type: undefined N myWindow.setZOptions(anOptionValue)JavaScript syntax: N setZOptions(anOptionValue) Argument list: anOptionValue One of a range of possible settings for the feature Refer to: Window.setZOptions() Shadow() (Filter/visual) A visual filter for creating a shadow. Availability: JScript 3.0 Internet Explorer 4.0 1924