The narrative of the book has a single focus - implementing a moderately big example. If you like plenty of code then this will please you however you will have to work at understanding the ideas from the code.
Chapter 5 is where things begin to go a little wrong - and it isn't really the book's fault. The subject is creating web apps that can work offline and this is where we first meet the problems of working with standards that are implemented differently by each of the browsers. At the start of the chapter it says
Caution The browser support for offline storage is in an early stage, and there are a lot of inconsistencies.
Other similar messages can be found in a lot of the remainder of the book. The caution is certainly accurate but it raises the question of what such flaky technologies are doing in a book about creating "pro" apps. No real solutions are provided to most of the inconsistencies pointed out and hence you can't really treat any of the techniques as secure enough to be used unless you limit your attention to a particular browser. Even then there are usually problems with implementation.
The application cache is the main topic of Chapter 5. Local storage is the topic of Chapter 6 with a brief explanation at the end using IndexDB. Chapter 7 is a mixture of topics under the heading of responsive web apps - setting the viewport, screen size changes and using jQuery UI. The final part of the chapter is about using touch and again it is admitted that the raw APIs aren't ready for pro use and so we have to use a library - TouchSwipe in this case. Chapter 8 is about creating mobile web apps - user agent detection and using jQuery Mobile.
Overall this is quite a good book if what you are looking for is a set of long examples. Much of the code is repetitive and the relevant parts being discussed in the text are generally highlighted in bold. Often it seems that a page of HTML is presented simply to show a single bold line of interest. You might like this style of presentation but I think it wastes space and makes it harder to focus on what is important.
How much you will get from this book depends on how persistent you are at following the example. There are lots of small valuable chunks of advice and ideas but these are hard to pull out from a narrative. The one idea you can't help but come away with is that much of this technology is not ready for "pro" use. Perhaps in a year or so...
|Last Updated ( Saturday, 01 December 2012 )|