UIPickerView and a Giant Contact List?

I'm new to iOS Development and am trying to make an application that essentially sorts through a list of 300 names or so. I've got the Drill-Down part of the application down, aside from the detailView, but am now faced with a challenge.

What I would like to do is have users select from 3 fields with a UIPickerView to come up with shorter lists for every time a user is looking for a person. I'd like to use a .plist, but I also have an XML feed of the information. Before I waste all of my time structuring these data sources, does anybody have a good overview as to how I should approach this?

Also, I've asked some this question before, and they tell me to read up on introductory iOS development topics. I understand the mechanics of development, I just can't ever figure out how to approach a task properly. (I'm working on it!)

Thanks in advance. I'd share an image to he开发者_JAVA技巧lp clarify, but my rep isn't high enough.

---

Snip: It looks like I misread your intention which makes my earlier comments irrelevant, you want to have the user select one of 3 options to shrink the list, if I'm not mistaken.

Some more questions for you, so I take it that this XML feed is going to be potentially changing between times that the user loads up the app? Will it only ever grow or are those 300 or so names that are loaded once set for good? The reason I ask so that you can maybe see my train of thought is whether or not using Core Data might be useful. You could easily store your large list locally, save time having to reload this large list frequently, and also you can use the built fetchedObjectController to search your collection of names. I'll keep thinking about it and once you get a chance to answer these questions we can continue.

Ill check back for an edit or comment, and see if I can give you an approach. Also, maybe edit your question with any of your own approach ideas and we could also start from there and refine them if needed.

Edit 2: From the information in the comments this is one of the ways that I could see this being done that make sense to me:

Since you seem to be able to control the information you receive from the feed I would set it up to send you only the contacts that need to be added/removed. You could handle this a few ways depending on your deployment intentions but I would go with the following:

Find a way to signal a first time run of the application, and as a result all contacts would be new, and you could populate your list fully with a slightly longer first time setup. Then any further changes could be quickly handled by smaller edits made to the local list.

You would need to set up Core Data for your application, which should be fairly straightforward in your case, and after this you can use the built in NSFetchRequest to do your searches that will then quickly return a list of narrowed down contacts. As for the physical picker that is just a matter of building the UI which will require some design from your end as you are the only one that knows what you are going for in that regard. Depending on the complexity of your app and what functionality you will want to include you could get away with 1-2 views that simply do the displaying of the contacts in a table and then the picker just reloads when appropriate.

I'm not familiar with the implementation of XML Feeds and receiving data from them, but I have done XML Response parsing into Core Data from a SOAP service before and they shouldn't be terribly different.

Regarding resource to get you started should you need them, I would recommend the following:

eBooks:

• http://www.techotopia.com/index.php/Objective-C_2.0_Essentials
• http://www.techotopia.com/index.php/IPhone_iOS_4_Development_Essentials_Xcode_4_Edition

Tutorials:

• http://www.raywenderlich.com/

The eBooks I have linked are both absolutely fantastic and one of the few xCode 4.0 books that I was able to find that seemed to be of an actual usable quality. They both contain easy to follow and clear tutorials on simple and more advanced aspects of programming for iOS.

Ray's site is an immensely helpful resource as it contains both a very active forum base for iOS programming in addition to a constantly growing tutorial collection as there are 4-5 people that constantly are creating new tutorials that the community votes on and suggests every week. It contains some more advanced topics than the above books and I would recommend looking at it after doing a few walk through/tutorials from the books.

I'll stick around if you have any further questions, otherwise you can send me a notification via these comments, or just post another question and someone is bound to help you out!

-Karoly