PDA

View Full Version : Time for studying ExtJS 3



xcodex
22 Nov 2011, 3:58 AM
Hello,

Can anyone tell me what's the average time in days for a developer who is being working in PHP for the last 5 years and jQuery for 2 years ? Mostly into backend programming with 'just-know' in frontend/pure javascript.

We have a big and complex project in ExtJS which was partially done by an experienced person in ExtJS and no documentation were made on this before he left the company. Just wondering to know, how much time the developer should spend studying ExtJS basic and start working on the project directly.

Thank you

tobiu
22 Nov 2011, 4:07 AM
It really depends on how complex the app is.
IMHO it can take longer to learn the business-logic & extensions / modifications the app makes on the ext framework than ext 3 itself. The best thing to learn Ext JS is to play around with the examples and actually write code. Keep in mind, that the examples often don't follow best coding practices though.

Since Ext JS 4.1 is just around the corner, it also might make sense to take a look at the beautiful MVC pattern and the new class system.

skirtle
22 Nov 2011, 11:27 AM
I don't think it's possible to give a figure in days. Some people pick it up quite quickly whereas others never get it. It took me about 6 months before it clicked and I stopped trying to write JavaScript like it's Java.

Two things that can massively reduce learning time are:


Strong JavaScript knowledge, including a firm grasp of how the prototype chain works. If you don't have this knowledge then get a book and learn JavaScript, you'll have no chance picking up ExtJS without it.
Prior knowledge of other UI toolkits and the patterns they use. I'm told that Java Swing, for example, has a lot of similar concepts to ExtJS.


I'd advise putting some time into learning about the layout managers, they're a common source of problems for beginners.

Learning the best practices is difficult because there isn't a clear place to learn them. As tobiu mentioned, the code behind the official demos isn't always a good example of how to write a large application.

The single best piece of advice I've seen on learning ExtJS is to dig into the source code. That doesn't mean sitting down and reading it, more that if you don't understand something you should click on the 'View source' links in the documentation and try to figure it out. You'll learn much faster and pick up a lot of best practices that way. It can be difficult to understand at first but it gets much easier.

I feel that a lot of your learning will be dependent on the project you have. If it was written using 'best practices' then you'll pick up those best practices. If it's a total mess (most ExtJS projects I've seen are) then you'll just pick up bad habits. Unfortunately it's not necessarily going to be straightforward for you to judge which case you're in. As with most code, if it's been well written then it should be 'self-documenting', so it should be fairly clear what's going on even if you're not yet confident on how to make changes.

If you aren't yet confident with ExtJS 3 then I wouldn't advise going anywhere near ExtJS 4, that's just too many steps at once.