Chapter 19: JavaScript: Adding Dynamic Content to Web Pages

Note: this page applies to the now-obsolete first edition of the book. For the second edition, please see http://www.corewebprogramming.com.

Contents

• Programs/Documents in this Chapter
• URLs in this Chapter
• Core Web Programming on-line ordering page. 20% off at amazon.com; ships in 24 hours.
• Books with more details on JavaScript.

Programs/Documents in this Chapter

• JavaScriptTemplate.html. Shows the basic structure of how you insert SCRIPT elements into the BODY part of an HTML document.
• FirstScript.html. A very simple page where JavaScript builds part of the HTML.
• ShowInfo.html. A page that shows information about the page and browser. Illustrates that JavaScript can generate different HTML in different situations.
• NonJavaScriptVersion.html. One alternative for building sites that support both JavaScript and non-JavaScript browsers. In this approach, the original page is written without JavaScript, but has a single JavaScript entry that forwards JavaScript-capable browsers to a new page.
• JavaScriptVersion.html. This is the page people with JavaScript browsers end at when visiting NonJavaScriptVersion.html.
• DontClick.html. A simple illustration that JavaScript can be used to monitor user events, not just to dynamically build HTML.
• ForIn.html. An illustration of the use of the for(field in object) construct.
• DynamicTable.html. An example of how JavaScript can be used to selectively make use of browser extensions. Here, the table headings are white text on black background in Netscape and IE 3 or later, but not in Netscape 2, which understands the "use white text" part but not the "use a black background" part, and would otherwise have unreadable white-on-white headings.
• Strawberries.html. Illustrates that in JavaScript 1.2 (Netscape 4), you can look up the browser window size and adjust image and font sizes appropriately.
• Plugins.html. Shows how JavaScript 1.1 and 1.2 can access information about your browser's available plugins.
• ImageButton.html. Using JavaScript to animate images, you can create an image button that, when clicked, takes you to a specific URL and is briefly displayed in inverse video when clicked.
• HighPeaks.html. Illustrates the use of JavaScript to "highlight" clickable images when they are under the mouse. The actual JavaScript code is in the HighPeaksNavBar.html frame cell.
• HighPeaksNavBar.html. Used in the HighPeaks example, this frame cell has the actual JavaScript image-manipulation code. It works on all JavaScript browsers that support images, but does not cause errors on those that don't.
• HighPeaksIntro.html. This frame cell shows the initial "main text" in the HighPeaks example.
• Camps.html. This illustrates the use of JavaScript to manipulate HTML "layers". Here, the layers appear/disappear and move around on the screen based on user actions.
• CheckText.html. An example of using JavaScript to validate individual CGI form fields one at a time. Note that there is not really a CGI program at the other end that shows available training courses; the field validation via JavaScript is the point here.
• Numbers.html. An illustration of how to validate the format of numbers in different JavaScript versions.
• CheckSeveral.html. An example of using JavaScript to validate multiple CGI form fields in one fell swoop when the form is submitted. Note that there is not really a CGI program at the other end that registers you for camp; the field validation via JavaScript is the point here.
• Widgets.html. This illustrates how JavaScript can manipulate cookies: reading and parsing existing values, and asking you to store them persistently.
• ShowURL.html. Shows how JavaScript can manipulate frames. Here, a URL entered in one cell is displayed in another. This file is the place to start for trying it out, but GetURL.html is the place to go to see the actual JavaScript code.
• GetURL.html. Code used in ShowURL.html.
• DisplayURL.html. Initial frame cell contents for ShowURL.html.
• Summary of how to call Java from JavaScript. On-line excerpt from section 19.9.
• CallJava.html. This illustrates how JavaScript with LiveConnect can call builtin Java methods directly. Works only in Netscape 3 and 4 and the Windows 95/NT versions of Internet Explorer 4.
• Wonder-Widget.html. This illustrates how JavaScript with LiveConnect can call methods in applets that are embedded in the current page. In this particular case, the applet provides the client hostname (something JavaScript can't check directly), and different resumes are provided depending on whether the reader is inside the company or outside. Works only in Netscape 3 and 4 and the Windows 95/NT versions of Internet Explorer 4.
• GetHost.java. This is the applet used by Wonder-Widget.html.
• ResumeLoyal.html. This is the resume given to readers of Wonder-Widget.html who are reading from company computers.
• ResumeReal.html. This is the resume given to external readers of Wonder-Widget.html.
• MoldSimulation.html. Shows how JavaScript can control applets. Works only in Netscape 3 and 4 and the Windows 95/NT versions of Internet Explorer 4.
• RandomCircles.java. The applet embedded in MoldSimulation.html.
• Summary of how to call JavaScript from Java. On-line excerpt from section 19.10.
• ShowHTML.java. A Netscape-3 specific way of building HTML on-the-fly and displaying it, all from a Java applet that does not use the JSObject class.
• TestHTML.java. Driver/test applet for the ShowHTML class.
• TestHTML.html. On-line test of the TestHTML applet. This will only work if you try it from Netscape 3.x.
• TestHTMLTop.html. Frame cell used in TestHTML example.
• TestHTMLBottom.html. Frame cell used in TestHTML example.
• MatchColor.html. Shows how Java can call JavaScript to get information about the page the applet is embedded in. Here, it looks up the color of the surrounding page and matches it. Works only in Netscape 3 and 4 and the Windows 95/NT versions of Internet Explorer 4.
• MatchColor.java. Applet used by MatchColor.html.
• Everest.html. A Java applet that controls HTML form values. Works only in Netscape 3 and 4 and the Windows 95/NT versions of Internet Explorer 4. Note that the form submission button is not really attached to anything; the Java-JavaScript interaction is the point here.
• Everest.java. Code used for applet in Everest.html. Requires the LabeledCostSlider, CostSlider, Slider, and ScrollbarPanel classes.
• LabeledCostSlider.java. A numeric slider class with attached label. Used in the Everest example.
• CostSlider.java. A slider class that lets you read numeric values. Used in the LabeledCostSlider class.
• Slider.java. A slider class: a combination of Scrollbar and TextField. Used in the CostSlider class.
• ScrollbarPanel.java. A Panel with adjustable top and bottom insets, used by the Slider class to change the thickness of the Slider.

URLs in this Chapter

• JavaScript Documentation from Netscape: http://developer.netscape.com/library/documentation/javascript.html
• JScript Documentation from Microsoft: http://www.microsoft.com/JScript/us/techinfo/jsdocs.htm