CD-532 Part VI ✦ Appendixes are perfectly usable in if conditional phrases). If this kind of browser detection occurs frequently in your pages, consider moving these functions into an external .js source library for inclusion in your pages (see Chapter 13). When you load this page, it presents fields that display the results of each function depending on the type of browser and client operating system you use. Listing 28-1: Functions to Examine Browsers <HTML> <HEAD> <TITLE>UserAgent Property Library</TITLE> <SCRIPT LANGUAGE=”JavaScript”> // basic brand determination function isNav() { return (navigator.appName == “Netscape”) } function isIE() { return (navigator.appName == “Microsoft Internet Explorer”) } // operating system platforms function isWindows() { return (navigator.appVersion.indexOf(“Win”) != -1) } function isWin95NT() { return (isWindows() && (navigator.appVersion.indexOf(“Win16”) == -1 && navigator.appVersion.indexOf(“Windows 3.1”) == -1)) } function isMac() { return (navigator.appVersion.indexOf(“Mac”) != -1) } function isMacPPC() { return (isMac() && (navigator.appVersion.indexOf(“PPC”) != -1 || navigator.appVersion.indexOf(“PowerPC”) != -1)) } function isUnix() { return (navigator.appVersion.indexOf(“X11”) != -1) } // browser versions function isGeneration2() { return (parseInt(navigator.appVersion) == 2) } navigator.appCodeName CD-533 Appendix F ✦ Examples from Parts III and IV function isGeneration3() { return (parseInt(navigator.appVersion) == 3) } function isGeneration3Min() { return (parseInt(navigator.appVersion.charAt(0)) >= 3) } function isNav4_7() { return (isNav() && parseFloat(navigator.appVersion) == 4.7) } function isMSIE4Min() { return (isIE() && navigator.appVersion.indexOf(“MSIE”) != -1) } function isMSIE5_5() { return (navigator.appVersion.indexOf(“MSIE 5.5”) != -1) } function isNN6Min() { return (isNav() && parseInt(navigator.appVersion) >= 5) } // element referencing syntax function isDocAll() { return (document.all) ? true : false } function isDocW3C() { return (document.getElementById) ? true : false } // fill in the blanks function checkBrowser() { var form = document.forms[0] form.brandNN.value = isNav() form.brandIE.value = isIE() form.win.value = isWindows() form.win32.value = isWin95NT() form.mac.value = isMac() form.ppc.value = isMacPPC() form.unix.value = isUnix() form.ver3Only.value = isGeneration3() form.ver3Up.value = isGeneration3Min() form.Nav4_7.value = isNav4_7() form.Nav6Up.value = isNN6Min() form.MSIE4.value = isMSIE4Min() form.MSIE5_5.value = isMSIE5_5() form.doc_all.value = isDocAll() Continued navigator.appCodeName CD-534 Part VI ✦ Appendixes Listing 28-1 (continued) form.doc_w3c.value = isDocW3C() } </SCRIPT> </HEAD> <BODY onLoad=”checkBrowser()”> <H1>About This Browser</H1> <FORM> <H2>Brand</H2> Netscape Navigator:<INPUT TYPE=”text” NAME=”brandNN” SIZE=5> Internet Explorer:<INPUT TYPE=”text” NAME=”brandIE” SIZE=5> <HR> <H2>Browser Version</H2> 3.0x Only (any brand):<INPUT TYPE=”text” NAME=”ver3Only” SIZE=5><P> 3 or Later (any brand): <INPUT TYPE=”text” NAME=”ver3Up” SIZE=5><P> Navigator 4.7: <INPUT TYPE=”text” NAME=”Nav4_7” SIZE=5><P> Navigator 6+: <INPUT TYPE=”text” NAME=”Nav6Up” SIZE=5><P> MSIE 4+: <INPUT TYPE=”text” NAME=”MSIE4” SIZE=5><P> MSIE 5.5:<INPUT TYPE=”text” NAME=”MSIE5_5” SIZE=5><P> <HR> <H2>OS Platform</H2> Windows: <INPUT TYPE=”text” NAME=”win” SIZE=5> Windows 95/98/2000/NT: <INPUT TYPE=”text” NAME=”win32” SIZE=5><P> Macintosh: <INPUT TYPE=”text” NAME=”mac” SIZE=5> Mac PowerPC: <INPUT TYPE=”text” NAME=”ppc” SIZE=5><P> Unix: <INPUT TYPE=”text” NAME=”unix” SIZE=5><P> <HR> <H2>Element Referencing Style</H2> Use <TT>document.all</TT>: <INPUT TYPE=”text” NAME=”doc_all” SIZE=5><P> Use <TT>document.getElementById()</TT>: <INPUT TYPE=”text” NAME=”doc_w3c” SIZE=5><P> </FORM> </BODY> </HTML> Sometimes you may need to use more than one of these functions together. For example, if you want to create a special situation for the window.open() bug that afflicts UNIX and Macintosh versions of Navigator 2, then you have to put your Boolean operator logic powers to work to construct a fuller examination of the browser: function isWindowBuggy() { return (isGeneration2() && (isMac() || isUnix())) } navigator.appCodeName CD-535 Appendix F ✦ Examples from Parts III and IV You can see many more examples of browser sniffing, including more details about handling AOL browsers, in an article by Eric Krock at: http://developer. netscape.com:80/docs/examples/javascript/browser_type.html . appMinorVersion NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓ Example Use The Evaluator (Chapter 13) to examine the two related version properties of your IE browser(s). Type the following two statements into the top text box and observe the results: navigator.appVersion navigator.minorAppVersion There is a good chance that the values returned are not related to the browser ver- sion number shown after MSIE in the appVersion value. cookieEnabled NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓✓✓ Example Use The Evaluator to see the value of the navigator.cookieEnabled property on your browsers. Enter the following statement into the top text box: navigator.cookieEnabled Feel free to change the cookie preferences setting temporarily to see the new value of the property. You do not have to relaunch the browser for the new setting to take effect. navigator.cookieEnabled CD-536 Part VI ✦ Appendixes cpuClass NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓ Example Use The Evaluator (Chapter 13) to see how IE reports the cpuClass of your PC. Enter the following statement into the top text box: navigator.cpuClass mimeTypes NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓ (✓)(✓)(✓) Example For examples of the mimeTypes property and details about using the mimeType object, see the discussion of this object later in the chapter. A number of simple examples showing how to use this property to see whether the navigator object has a particular MIME type do not go far enough in determining whether a plug-in is installed and enabled to play the incoming data. onLine NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓ Example Use The Evaluator (Chapter 13) to see the online state of your IE browsers. Enter the following statement into the top text box: navigator.onLine navigator.onLine CD-537 Appendix F ✦ Examples from Parts III and IV Verify your browsing mode by checking the Work Offline choice in the File menu. If it is checked, the onLine property should return false. oscpu NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓ Example Use The Evaluator (Chapter 13) with NN6 to see what your client machine reports to you by entering the following statement into the top text box: navigator.oscpu platform NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓✓✓ Example Use The Evaluator (Chapter 13) to see what your computer reports as its operating system. Enter the following statement into the top text box: navigator.platform product productSub vendor vendorSub NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓ navigator.product CD-538 Part VI ✦ Appendixes Example Use The Evaluator (Chapter 13) on your copy of NN6 to see the values returned for these four properties. Enter each of the following statements into the top text box of the page and see the values for each in the Results box: navigator.product navigator.productSub navigator.vendor navigator.vendorSub Also check the value of the navigator.userAgent property to see how many of these four property values are revealed in the userAgent property. systemLanguage userLanguage NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓ Example Use The Evaluator (Chapter 13) with your IE4+ browser to compare the values of the three language-related properties running on your computer. Enter each of the following statements into the top text box: navigator.browserLanguage navigator.systemLanguage navigator.userLanguage Don’t be surprised if all three properties return the same value. Methods preference(name [, val]) NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ navigator.preference() CD-539 Appendix F ✦ Examples from Parts III and IV Example The page in Listing 28-2 displays checkboxes for several preference settings plus one text box to show a preference setting value for the size of the browser’s disk cache. To run this script without signing the scripts, turn on codebase principals as directed in Chapter 46. (The listing file on the CD-ROM does not employ signed scripts.) One function reads all the preferences and sets the form control values accordingly. Another function sets a preference when you click its checkbox. Because of the interaction among three of the cookie settings, it is easier to have the script rerun the showPreferences() function after each setting rather than you trying to man- ually control the properties of the three checkboxes. Rerunning that function also helps verify that you set the preference. Listing 28-2: Reading and Writing Browser Preferences <HTML> <HEAD> <TITLE>Reading/Writing Browser Preferences</TITLE> <SCRIPT LANGUAGE=”JavaScript1.2”> function setPreference(pref, value) { netscape.security.PrivilegeManager.enablePrivilege( “UniversalPreferencesWrite”) navigator.preference(pref, value) netscape.security.PrivilegeManager.revertPrivilege( “UniversalPreferencesWrite”) showPreferences() } function showPreferences() { var form = document.forms[0] netscape.security.PrivilegeManager.enablePrivilege( “UniversalPreferencesRead”) form.imgLoad.checked = navigator.preference(“general.always_load_images”) form.cacheSize.value = navigator.preference(“browser.cache.disk_cache_size”) form.ssEnable.checked = navigator.preference(“browser.enable_style_sheets”) form.autoIEnable.checked = navigator.preference(“autoupdate.enabled”) var cookieSetting = navigator.preference(“network.cookie.cookieBehavior”) for (var i = 0; i < 3; i++) { form.elements[“cookie” + i].checked = (i == cookieSetting) ? true : false } Continued navigator.preference() CD-540 Part VI ✦ Appendixes Listing 28-2 (continued) form.cookieWarn.checked = navigator.preference(“network.cookie.warnAboutCookies”) netscape.security.PrivilegeManager.revertPrivilege( “UniversalPreferencesRead”) } </SCRIPT> </HEAD> <BODY onLoad=”showPreferences()”> <H1>Browser Preferences Settings Sampler</H1> <HR> <FORM> <INPUT TYPE=”checkbox” NAME=”imgLoad” onClick=”setPreference(‘general.always_load_images’,this.checked)”> Automatically Load Images<BR> <INPUT TYPE=”checkbox” NAME=”ssEnable” onClick=”setPreference(‘browser.enable_style_sheets’,this.checked)”> Style Sheets Enabled<BR> <INPUT TYPE=”checkbox” NAME=”autoIEnable” onClick=”setPreference(‘autoupdate.enabled’,this.checked)”> AutoInstall Enabled<BR> <INPUT TYPE=”checkbox” NAME=”cookie0” onClick=”setPreference(‘network.cookie.cookieBehavior’,0)”> Accept All Cookies<BR> <INPUT TYPE=”checkbox” NAME=”cookie1” onClick=”setPreference(‘network.cookie.cookieBehavior’,1)”> Accept Only Cookies Sent Back to Server<BR> <INPUT TYPE=”checkbox” NAME=”cookie2” onClick=”setPreference(‘network.cookie.cookieBehavior’,2)”> Disable Cookies<BR> <INPUT TYPE=”checkbox” NAME=”cookieWarn” onClick=”setPreference(‘network.cookie.warnAboutCookies’,this.checked)”> Warn Before Accepting Cookies<BR> Disk cache is <INPUT TYPE=”text” NAME=”cacheSize” SIZE=10> KB <BR> </FORM> </BODY> </HTML> navigator.preference() CD-541 Appendix F ✦ Examples from Parts III and IV screen Object Properties availLeft availTop NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ Example If you are a Windows user, you can experiment with these NN4+ properties via The Evaluator (Chapter 13). With the taskbar at the bottom of the screen, enter these two statements into the top text box: screen.availLeft screen.availTop Next, drag the taskbar to the top of the screen and try both statements again. Now, drag the taskbar to the left edge of the screen and try the statements once more. userProfile Object Methods addReadRequest(“attributeName”) NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility ✓✓ ✓ userProfile.addReadRequest() . CD-532 Part VI ✦ Appendixes are perfectly usable in if conditional phrases). If this kind of browser detection occurs. Browsers <HTML> <HEAD> <TITLE>UserAgent Property Library</TITLE> <SCRIPT LANGUAGE= JavaScript > // basic brand determination function isNav() { return (navigator.appName == “Netscape”) } function. (parseInt(navigator.appVersion) == 2) } navigator.appCodeName CD-533 Appendix F ✦ Examples from Parts III and IV function isGeneration3() { return (parseInt(navigator.appVersion) == 3) } function