Objective C - call NSNumber outside FOR loop - objective-c

Question

It seems that i didn't cover my basics enough, but I hope that You guys mabybe will be able to help here.
I need to use cateringView.status outside this loop and even in another class. This is simple BOOL value, parsed from XML with PUGIXML
- (void)dataPrepared
{
Food* food = (Food*)[[DataManager sharedInstance] dataForItem:kDataManagerItemCatering];
if (food)
{
for (CateringView* cateringView in cateringViews)
[cateringView removeFromSuperview];
[cateringViews removeAllObjects];
for (FoodItem* item in food.catering)
{
CateringView* cateringView = [CateringView new];
[cateringView.imageView loadURL:[NSURL URLWithString:item.image] session:[DataManager sharedInstance].session completion:nil];
cateringView.status = item.status;
[self addSubview: cateringView];
[cateringViews addObject: cateringView];
}
[self layoutSubviews];
}
[super dataPrepared];
}
Could You explain me how can I do that?
My header file:
(...)
#interface CateringView : UIView
#property (strong) NSNumber* status;
#end
#interface CateringPreviewCell : PreviewCell
{
NSMutableArray* cateringViews;
(...)
}
#end

Answer 1

Is this somebody else's code you are trying to understand? It is unclear what you are asking, but you appear to be confusing the lifetime of local variables and objects. Maybe the following will help:
The second for loop starts:
for (FoodItem* item in food.catering)
{
CateringView* cateringView = [CateringView new];
This last statements does two things:
The right hand side (RHS) creates a new object of type CateringView. The result of the RHS is a reference to the created object. The lifetime of the created object extends as long as there is a reference to it[A].
The left hand side (LHS) creates a new local variable called cateringView. The reference returned by the RHS is stored in this variable. The lifetime of the created variable is a single iteration of the for loop.
At the end of the loop the code is:
[self addSubview: cateringView];
[cateringViews addObject: cateringView];
}
These two statements take the reference, to the created CateringView object, which is stored in the local variable cateringView and add it to this object's (which is an instance of the CateringPreviewCell class) subviews and cateringViews instance variable.
After these two statements have executed you have stored the reference to the created CateringView object three times: in the local variable cateringView, in the owning object's subviews, and in the owning object's cateringViews instance variable.
Also after these statements the loop iteration ends, so the lifetime of the local variable cateringView ends and you can no longer use that variable. However the reference to the object that was stored in that local variable still exists in two locations and that object is still alive.
You are stating you need to access cateringView.status outside of the loop. That does not make sense, the variable does not exist. However the object the variable referenced when it did exist is still alive, so the status value you seek is still around - you are just looking in the wrong place.
After the loop, and after the call to dataPrepared has returned, all the CateringView objects created can be accessed either:
as subviews of the object instance of CateringPreviewCell that dataPrepared was called on, or
as members of the instance variable cateringViews of that object instance.
The first of these is accessible "outside the class", the second can be provided you have instance methods defined on CateringPreviewCell which provided access to the instance variable.
HTH
[A]: This is not exactly true, but sufficient for the purpose here. Later you may learn about things such as weak references which do not govern how long an object lives.

Answer 2

You wouldn't use cateringView, because you actually have many of them. They're all stored in cateringViews so that's what you'd actually use. You'd either iterate all the views in that array or you'd choose one at a specific index to interact with.

Answer 3

Without knowing whether your intention is to try to add .status to
existing objects inside the cateringViews array
or
new objects that you add to cateringViews array
since your question has missing information and isn't very clear, here is the solution for #2
for (CateringView* cateringView in self.cateringViews) { //needed curly braces and self. to access property var
[cateringView removeFromSuperview];
}
[self.cateringViews removeAllObjects]; //again needed self.
for (int i = 0; i < food.catering.count; i++) { //make sure food.catering is array and not nil
CateringView* cateringView = [[CateringView alloc] init];
[cateringView.imageView loadURL:[NSURL URLWithString:item.image]
session:[DataManager sharedInstance].session
completion:nil];
FoodItem *item = food.catering[i]
cateringView.status = item.status;
[self addSubview: cateringView];
[self.cateringViews addObject: cateringView];
}
If I'm wrong and you're trying to accomplish #1, (consider improving your question wording if this is the case) then you'll need to loop through self.cateringViews as well.