Head First Ajax英文版
Chapter 1. using ajax.................................................................................... 1
Section 1.1. Web pages: the old-fashioned approach..................................................................................................................... 2
Section 1.2. Web pages reinvented................................................................................................................................................. 3
Section 1.3. So what makes a page "Ajax"?..................................................................................................................................... 5
Section 1.4. Rob's Rock 'n' Roll Memorabilia................................................................................................................................. 6
Section 1.5. Ajax and rock 'n' roll in 5 steps.................................................................................................................................. 12
Section 1.6. Step 1: Modify the XHTML........................................................................................................................................ 14
Section 1.7. Step 2: Initialize the JavaScript................................................................................................................................. 16
Section 1.8. Step 3: Create a request object.................................................................................................................................. 20
Section 1.9. Step 4: Get the item's details..................................................................................................................................... 22
Section 1.10. Let's write the code for requesting an item's details............................................................................................... 24
Section 1.11. Always make sure you have a request object before working with it...................................................................... 25
Section 1.12. The request object is just an object......................................................................................................................... 26
Section 1.13. Hey, server... will you call me back at displayDetails(), please?............................................................................. 27
Section 1.14. Use send() to send your request.............................................................................................................................. 28
Section 1.15. The server usually returns data to Ajax requests.................................................................................................... 30
Section 1.16. Ajax is server-agnostic.............................................................................................................................................. 31
Section 1.17. Use a callback function to work with data the server returns................................................................................. 35
Section 1.18. Get the server's response from the request object's responseText property.......................................................... 36
Section 1.19. Goodbye traditional web apps................................................................................................................................. 38
Section 1.20. AjaxAcrostic............................................................................................................................................................. 39
Mobile applications come in two basic flavors: native applications, which are compiled programs that run natively on the device, and mobile web applications, which run inside a web browser on the device.
Native applications get almost all of the press these days, especially given the financial success of the iTunes App Store and the Android Market. And with good reason, as native applications have many advantages: they are fast, have access to all of the power of the platform they are built for, and so forth. However, native applications suffer from one important limitation: they are not portable. If you want to make your application available on multiple platforms, you either have to write it in multiple languages (resulting in multiple code bases to maintain) or use a platform abstraction layer like Titanium or PhoneGap.
Mobile web applications, on the other hand, are created in HTML, CSS, and JavaScript, and run in the web browser on the mobile device. This means one code base to maintain, but mobile web applications still need to account for variations in web browsers across platforms.
Enter jQuery Mobile. Based on the popular jQuery JavaScript library, jQuery Mobile is designed to create mobile web applications that function on a broad range of devices. With jQuery Mobile, it is possible to quickly create mobile web applications that look and behave consistently across all supported devices, and that have advanced user interface capabilities. jQuery Mobile gives the developer a standard set of layouts, user interface widgets, and interactions, as well as a rich API for applying and extending them.
jQuery Mobile is not yet in production—as of this writing, it is in its Alpha 4 release, with the beta coming soon.
Even so, the library already has a broad set of features and is remarkably stable. In fact, I have already used it in one production project with great success, and if you review posts on the jQuery Mobile forums, you’ll see that there are many people using jQuery Mobile in production. As jQuery Mobile advances, we hope to update this ebook to cover new features and provide new tips and techniques.
