Displaying content based on cookie contents: The repeat-visitor script in Java
Displaying content based on cookie contents: The repeat-visitor script QR Printer In Java Using Barcode creation for Java Control to generate, create QR image in Java applications. You can create a script that registers a user by saving the user s name to the user s hard drive by using a cookie On subsequent visits to the site, the script accesses the cookie from the user s hard drive, recognizes the user s name, and uses the information to display a custom greeting Figure 6-5 shows stage one of the repeat-visitor script where users must first register their names In many real-life applications, you want to create and access cookies by using a server-side technology, such as a CGI script Because CGI scripting is beyond the scope of this book, in this chapter I show you how to create and access cookies with JavaScript instead (The syntax between CGI scripting languages and JavaScript differs, but the basic ways that you interact with cookies are the same) After users register their names, as shown in Figure 6-5, they never see the registration form again Users can close their browsers, turn off their machines, and go away on vacation for a week When they return and attempt to access the registration page again, the script recognizes that they ve already registered and loads the For Registered Users Only page with a customized greeting (see Figure 6-6) Bar Code Generator In Java Using Barcode creation for Java Control to generate, create bar code image in Java applications. 6: That s How the Cookie Crumbles
Decoding Bar Code In Java Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications. Figure 6-5: Registering user input with cookies
QR Code Generator In C#.NET Using Barcode generation for VS .NET Control to generate, create QR Code 2d barcode image in VS .NET applications. Figure 6-6: Escorting your registered guest to a reserved page
Painting QR Code In .NET Framework Using Barcode generator for .NET Control to generate, create QR image in Visual Studio .NET applications. Part II: Creating Dynamic Web Pages
Denso QR Bar Code Creation In VB.NET Using Barcode printer for VS .NET Control to generate, create QR-Code image in .NET applications. I implemented the repeat-visitor script in two parts based on the two actions in Figure 6-5 and Figure 6-6: Cookie Example I (For Unregistered Users page): This script registers a user s name, stores a cookie on that user s machine, and loads the For Registered Users Only page Cookie Example II (For Registered Users Only page): This script accesses the cookie and displays a custom greeting When you create a cookie, you specify an expiration date After the specified expiration date, the cookie can no longer be accessed An expiration of the null value marks a cookie as transient (Transient cookies stay around in memory only as long as the user s browser session lasts; they aren t saved to the user s hard drive) In the example in Listing 6-1, you see an expiration date of one year from the time the cookie is created The Cookie Example I and Cookie Example II scripts are shown in Listings 6-1 and 6-2, respectively You can find them in the list0601htm and list0602htm files on the companion CD-ROM Generating Code 39 Extended In Java Using Barcode creation for Java Control to generate, create Code-39 image in Java applications. Listing 6-1: Encode Barcode In Java Using Barcode maker for Java Control to generate, create bar code image in Java applications. Cookie Example I: The Registration Form
Bar Code Printer In Java Using Barcode drawer for Java Control to generate, create bar code image in Java applications. <HTML> <HEAD><TITLE>Cookie Example I: The Registration Page (From JavaScript For Dummies, 4th Edition)</TITLE> <SCRIPT LANGUAGE= JavaScript TYPE= text/javascript > <!-- Begin hiding function getCookieVal (offset) { // This function returns the portion of the // myCookie=userName string // between the = and the ; var endstr = documentcookieindexOf ( ; , offset); if (endstr == -1) { endstr = documentcookielength; } return unescape(documentcookiesubstring(offset, endstr)); } function getCookie (cookieName) { EAN128 Creator In Java Using Barcode generator for Java Control to generate, create USS-128 image in Java applications. // You have to pick apart the cookie text To do this, // You start by figuring out how many characters are // in the string myCookie= Code 128 Code Set B Drawer In Java Using Barcode maker for Java Control to generate, create Code128 image in Java applications. 6: That s How the Cookie Crumbles
Leitcode Maker In Java Using Barcode generator for Java Control to generate, create Leitcode image in Java applications. var arg = cookieName + = ; var argLength = arglength; // Now find out how long the entire cookie string is var cookieLength = documentcookielength; // // // // // If cookies were stored as objects, life would be much easier! As it is, you must step through the contents of a cookie character by character to retrieve what is stored there Bar Code Reader In Java Using Barcode decoder for Java Control to read, scan read, scan image in Java applications. var i = 0; // While the i counter is less than the number // of characters in the cookie while (i < cookieLength) { // Offset the j counter by the number of characters // in myCookie= var j = i + argLength; // If you find myCookie= in the cookie contents if (documentcookiesubstring(i, j) == arg) { // return the value associated with myCookie= return getCookieVal(j) } if (i == 0) { break } } return null; } function setCookie(name, value) { // Capture all the arguments passed to the // setCookie() function var argv = setCookiearguments; // Determine the number of arguments passed into // this function var argc = setCookieargumentslength; // You expect the third argument passed in to // be the expiration date // If there isn t a third argument, set the expires // variable to null // (An expiration date of null marks a cookie as // transient Transient cookies are not saved to the // user s hard drive) var expires = (argc > 2) argv[2] : null; (continued) UPC-A Supplement 2 Printer In Visual C#.NET Using Barcode generation for .NET Control to generate, create UPC-A Supplement 5 image in .NET applications. Barcode Generation In .NET Framework Using Barcode generation for .NET framework Control to generate, create bar code image in .NET framework applications. UPC-A Supplement 5 Printer In VB.NET Using Barcode drawer for Visual Studio .NET Control to generate, create UPC Code image in .NET framework applications. Scanning EAN13 In .NET Using Barcode decoder for VS .NET Control to read, scan read, scan image in .NET framework applications. |
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