Setting the value of a textbox from another page

Question

Hi Everyone,
I have a multi paged application (multiple xib, multiple controllers)
In my selection view, the view that holds the UIViewPicker control, I need to populate the page that called the selector page...
I have the code to identify what page called the selector, and when the page is dismissed, I need to fill in the field from the calling page.
I have included the header of the calling view in my selector view, and now I need to be able to fill in a readonly textbox in the calling view....
Do I need to setup a property for each of the textboxes in the calling view, or can I populate them directly??
thanks
tony

Answer 1

alt-088 wrote:
I am sorry, but I am lost in this implementation....
How exactly do I tell the self.parentViewController what control will receive the new text value??
Ooooops!! I'm the one who needs to be sorry, Tony:
// from previous post
- (void)setTextInParent:(NSString* textValue) {
// assume that every possible parent controller has a "textbox" object
// which is a member of some class that has a writable 'text' property
[previousViewController setValue:textValue forKey:@"text"]; // <-- * Idiot alert *
Looks like another one of my senior moments. As you pointed out, we need the value of the 'textBox' property before we can set the value of the 'text' property.
To your question on how I am displaying the second view, it is called via
[self presentModelViewController:screen animated:YES]
from a button click event
Cool. That means we already have the address of vc1 in the 'parentViewController' ivar of vc2, so we don't need to add the 'previousViewController' ivar shown in my example.
So here's a corrected and maybe more relevant example--this one has been tested (Duh!), btw:
- (IBAction)done {
// get the currently selected string
NSInteger row = [pickerView selectedRowInComponent:0];
NSString *selection = [dataArray objectAtIndex:row];
NSLog(@"%s: selection=%@", _func_, selection);
// set text in textBox property of parent controller
[self.parentViewController setValue:selection forKeyPath:@"textBox.text"];
[self dismissModalViewControllerAnimated:YES];
I have tried to implement this code
[self.parentViewController setValue:21 forKey:@"test"];
but it is generating an error stating
passing argument 1 of 'setValue:forKey:' makes pointer from integer without a cast
Yeah, referring to the doc, [setValue:forKey:|http://developer.apple.com/iphone/library/documentation/Cocoa /Reference/Foundation/Protocols/NSKeyValueCodingProtocol/Reference/Reference.html#//appleref/occ/instm/NSObject/setValue:forKey:] wants an id type (pointer to an object of any Obj-C class) for the first arg. Since 21 is an int, i.e. a scalar value, the compiler doesn't like it (and the runtime system would like it even less).
However when you want to use KVC to set a scalar property, the methods are actually smart enough to extract an int if you provide a NSNumber object (see "Setting Attribute Values Using Key-Value Coding" under [Key-Value Coding Fundamentals|http://developer.apple.com/iphone/library/documentation/Cocoa/Conc eptual/KeyValueCoding/Concepts/BasicPrinciples.html#//apple_ref/doc/uid/20002170 ] in the Key-Value Coding Programming Guide). So if 'test' is an int ivar of the parent controller, something like this should work:
[self.parentViewController setValue:[NSNumber numberWithInt:21] forKey:@"test"];
Does that cover your questions? Sorry again for the bad code. Most of the examples I post are pasted directly from working, tested code, and I usually add a disclaimer if it's just something I keyed into the forum. But when I"m having a senior moment all bets are off.
- Ray