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iOS

Posted by Tom Coomer
Tom Coomer
1,331 Points

Picker view not updating textview

I have an array that is created from a Parse query. The NSLog displays the correct information however It crashes when I ask it to display in the textview. I am also able to have the textview display a set string (on the 3rd line that is commented out). Any ideas? Here is my code below: 

-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    self->documentContentString = [self->contentArrayPicker objectAtIndex:row];
    //self->documentContentString = @"test";
    NSLog(@"%@",self->documentContentString);

    self->documentContent.text = self->documentContentString;
}
John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

Can you please provide the declaration of self->documentContentString and self->contentArrayPicker

Tom Coomer
Tom Coomer
1,331 Points

It is declared in the ViewController.h file

@interface ViewController : UIViewController {
    IBOutlet UITextField *documentName;
    IBOutlet UITextView *documentContent;

    //Picker
    IBOutlet UIPickerView *documentPicker;
    NSArray *documentPickerData;
    NSArray *documentArray;
    NSArray *contentArrayPicker;

    NSString *documentNameString;
    NSString *documentContentString;
}

2 Answers

John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

At a quick glance I can't see anything wrong with the code. I think contentArrayPicker must be populated with something other than NSString. I'm not understanding why you are using a separate array, can you not simply write?

self->documentContentString = [pickerView objectAtIndex:row];

If this doesn't work, can you provide the code that populates contentArrayPicker.

Tom Coomer
Tom Coomer
1,331 Points

I am using a separate array as the picker view title is populated by a Parse query array of all the @"title" properties and the document content string from an array filled from the @"body" property from a Parse query.

The thing that I find odd is that the NSLog line prints the correct value for the documentContentString. It only crashes when it tries to fill the textview with the documentContentString value.

John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

I probably should have asked this first, but when you say "crashes" what error message is it giving? I'm guessing it's something to do with incompatible type.

Tom Coomer
Tom Coomer
1,331 Points

[PFObject copyWithZone:]: unrecognized selector sent to instance 0x170119aa0 (lldb)

I have an Exception breakpoint and it points to the line below:

self->documentContent.text = self->documentContentString;

Thanks

John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

That message is saying that documentContentString is a PFObject and is not an NSString object for some reason. I'm not sure how this is happening unless you are using casting when you populate contentArrayPicker. Make sure you are defiantly populating contentArrayPicker with valueForKey:@"body".

If this doesn't work I'll need to see the code that populates contentArrayPicker.

Tom Coomer
Tom Coomer
1,331 Points

This is the code that populates the contentArrayPicker:

PFQuery *contentQuery = [PFQuery queryWithClassName:@"Post"];
    [contentQuery selectKeys:@[@"body"]];
    NSArray *contentArray = [contentQuery findObjects];

    NSLog(@"%@",contentArray);
    [contentQuery findObjectsInBackgroundWithBlock:^(NSArray *contentObjects, NSError *contentError) {

    }];

    self->contentArrayPicker = contentArray;
John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

Alternatively try:

self->documentContent.text = [self->documentContentString valueForKey:@"body"];

This code shouldn't work unless something very strange is happening.

Tom Coomer
Tom Coomer
1,331 Points

That has worked! Thank you so much for your help!

John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

There are multiple things going wrong here. You are making two network calls and not getting the valueForKey. contentArray will be full of PFObjects and not NSStrings. You were also copying the array memory address and not the contents. Try the following code: 

PFQuery *contentQuery = [PFQuery queryWithClassName:@"Post"];
[contentQuery selectKeys:@[@"body"]];
NSMutableArray *contentArray = [NSMutableArray array];

[contentQuery findObjectsInBackgroundWithBlock:^(NSArray *contentObjects, NSError *contentError) {
    for (PFObject *contentObject in contentObjects) {
        [contentObject addObject:[contentObjects valueForKey:@"body"]];
    }
}];

self->contentArrayPicker = [contentArray copy];
John Wheal
John Wheal
27,969 Points
John Wheal
John Wheal
27,969 Points

I've only just seen your message that it worked. That's great but it's only working through a combination of mistakes. Anyway, at least it's sorted.

Tom Coomer
Tom Coomer
1,331 Points
Tom Coomer
Tom Coomer
1,331 Points

Okay. I will take a look at improving if. Thanks again.