Passing an array from NSObject to a View Controller

Question

Im fairly new to Objective-C. I am in the process of passing an array from an NSObject to a view controller (not my root). The NS object file, finishes with the array poolArray. Ive also used self.poolArray = nil; in void(dealloc). When passing this to my view controller, what are the steps I have to take?

Edit: To be more specific to my cause, what if I was just to deal with two view controllers?

-(void)createData {
    //poolFixtures being the text within each cell of my table view.
    NSMutableArray *poolFixtures; 

    groupSections=[[NSMutableArray alloc] initWithObjects: @"Pool Stages", nil]

    poolFixtures=[[NSMutableArray alloc] init];


    [poolFixtures addObject:[[NSMutableDictionary alloc]
     initWithObjectsAndKeys:@"This is a name",@"name",nil]];

    fixtureData=[[NSMutableArray alloc] initWithObjects: poolFixtures, nil];

    [poolFixtures release];
}

I have a similar set up for my second view controller. However, the titles needed for the second one require me to download data from a html file, parse them into the format i want etc. When used in the second view controller it takes a long time (I presume because of the html loading time). What I am trying to accomplish (what I thought i could do with an NSobject), is starting the data collection as soon as the user opens the app; so, by the time the user gets to the second view controller, it is loaded and ready.

Therefore I am wondering if I could do the downloading, and parsing in the root view controller, and send the array across to the second view controller for use when needed. I thought I would be able to use the createData part of my root implementation to do so.

I think you need to post some code to get a meaningful answer. — Rog, Jul 12 '11 at 16:13

score 1 · Accepted Answer · edited May 23 '17 at 12:11

1

For this, my suggestion is implement delegate methods. I guess u know about protocols in objective C. More info about delegate pattern.

Steps to do. 1. After ur app is launched, the view controller set the delegate and start downloading in background thread. 2. After the download is finished, the downloaded data will be set through the delegate methods.

Hope u will get my point. Any doubt, post it here.

edited May 23 '17 at 12:11

Community

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answered Jul 12 '11 at 17:32

Ilanchezhian

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Had a look at the link to apples URLCache (http://developer.apple.com/library/ios/#samplecode/URLCache/Introduction/Intro.html). Is that along the lines of what I want to accomplish? – Michael M Jul 12 '11 at 20:25

score 0 · Answer 2 · edited Jul 12 '11 at 16:13

0

I may be misunderstanding you, but this is what you typically do....

Object obj = [[Object alloc] init];
ViewController *vc = [[ViewController alloc] initWithNibName:@"NibName" bundle:nil];
// this is a public property of the viewcontroller
vc.array = [object methodThatReturnsArray]; 
[self.navigationController pushViewController:vc];

This is what the methodThatReturnsArray would look like

-(NSArray *)methodThatReturnsArray
{
   NSArray* array = [[[NSArray alloc] init] autorelease];
   // some code here that adds to the usefulness of the array
   return array;
}

edited Jul 12 '11 at 16:13

Rog

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answered Jul 12 '11 at 16:04

Trevor

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The return statement should be like `return [array autorelease]`. – Ilanchezhian Jul 12 '11 at 16:09
@Gomathi `array` is already `autorelease`d. To add, no point creating an empty immutable object. – Deepak Danduprolu Jul 12 '11 at 16:15
@Gomathi: he has an autorelease on his init statement. Doing [array autorelease] won't do anything. – ColdLogic Jul 12 '11 at 16:16
2

@ColdLogic it is one additional `release` than required. Eventually, it will release a deallocated object. – Deepak Danduprolu Jul 12 '11 at 16:17
Ive just updated the initial question to be a little more specific, any input is really appreciated! – Michael M Jul 12 '11 at 16:41
@ColdLogic & Deepak: Actually when I made that comment, autorealease was not there. Pl. check edit history. – Ilanchezhian Jul 12 '11 at 17:04

Passing an array from NSObject to a View Controller

2 Answers2