Where Does JQuery/Client-Side Programming Fit Into MVP and DDD

I'm working on an a pretty big project right now and am trying to implement an MVP architecture. I'm starting to run across a insta开发者_如何转开发nces where I think JQuery or Javascript might be better suited than server-side code. I'm looking for feedback on how others are implementing client-side programming into their enterprise applications. How are you structuring the client-side code and how do you determine when to use it?

1. Things that can make user say "wow". For example - Populating search results while user has just typed 3-4 character of search term. Just go back in past and think about Yahoo or Hotmail which used to postback to server when you clicked on "Create Message". But when google came they just did on client side without going to server. I bet you would have said "wow" to that. At least I did.
2. Things that can reduce server load. For example - Adding extra data entry row in HTML table, instead of doing it through round trip, Increase/Decrease of quantity etc.

These are just some example to sight. Even to do these things properly you need to go to server but that will be behind the scene using ajax. Other than this you need to select few more jquery plugins that you will use in your project. To name some are jQuery UI, jQuery Validation, jQuery AnythingSlider etc. There are too many of them.

Http://ClearTrip.com is one site that I envy for their UX. Visit their site from mobile device and you will get further clues about their UX work. Besideds just coding you need to have a person in your team who can work on these UX aspects.

Regarding how this fits into DDD: I've just recently started my journey into DDD but one hears a lot about command/query separation in that circle. Certainly if you are doing something that hits your domain (like fetching for auto-completion or certainly if you allow partial page submission to accomplish a domain command) you have to decide how it gets there and how the domain is structured to handle it.

I think two decisions are most relevant.

First, bits entirely in the browser and even those specifically in your application layer are outside your domain and thus, though covered in the layered architecture part of the DDD discussion, do not land in the entity/value/event/service, etc. discussion. If, however, you are using AJAX to interact with your application layer and in turn need to access your domain, you need to consider again two things in my mind.

(a) Are you separating commands and queries simply using different methods on your domain? Fine if you have a relatively small demand for either queries or commands and this will not seem like "noise" in your domain API. Otherwise, you have a separate bounded context...another domain modeled just for queries that your UI needs to avoid clutter on your domain. Regardless, you are doing something like JS->AJAX handler in application layer->domain (including a domain service).

(b) Is this a command or a query? Once you have (a) figured out, this lets you know where the access will land...then use the presentation layer's use case to elaborate the domain concept and put it into your ubiquitous language.

Second, you have the DTO vs direct to domain decision. This can be a religious war gathering topic, but usually the answer is "depends." I think there are cases for using DTOs and cases for not (within the same architecture)...just search for all the discussions around the topic and apply the pattern only where it adds value; I won't try to cover details here.

Hope this provides some insight or at least conversation magnet to which others will add.

I guess this question is a little too subjective. Looks like I'm just going to grab a view books on advanced javascript and study up on the JQuery library.