Unable to pass a NSString from One VC to Next VC - ios

Question

I have two VCs and i want to pass resourceName from HomeViewController to SingleWebViewController. But the resourceName is getting null.
HomeViewController.m
#import "HomeViewController.h"
#import "SingleWebViewController.h"
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
singleWebViewController = segue.destinationViewController;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
selectedRow = indexPath.row;
switch (selectedRow)
{
case 0:
{
singleWebViewController.resourceName=#"intro";
NSLog(#"HtmlFileName:%#" , singleWebViewController.resourceName);
[self performSegueWithIdentifier:#"toSingleWebView" sender:self];
break;
}
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
SingleWebViewController.h has the following line
#property (nonatomic,strong)NSString *resourceName;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
NSString *htmlFile = [[NSBundle mainBundle] pathForResource:self.resourceName ofType:#"html" inDirectory:nil] ;
NSLog(#"%#se:" , self.resourceName);
NSURL *url = [NSURL fileURLWithPath:htmlFile ];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[_webView loadRequest:request];
_webView.delegate=(id)self;
}
i did notice that didSelectRowAtIndexPath is getting called before prepareForSegue. what's the cause for this. Please suggest.

Answer 1

In prepareForSegue, you're assigning something new to singleWebViewController. If this controller is different from the controller that's already assigned in tableView: didSelectRowAtIndexPath:, which I assume it is, then your property will be reset.
Instead, do this:
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
singleWebViewController = segue.destinationViewController;
singleWebViewController.resourceName = #"intro";
}

Answer 2

In your prepareForSegue you can set the property resourceName
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
SingleWebViewController *singleWebViewController = segue.destinationViewController;
[singleWebViewController setResourceName:#"Resource name"];
}

Answer 3

try this..pass value in prepareforsegue
Edit: if you want for different case to pass the different value then do this..i m assuming you want to segueway to same ViewController ie SingleWebViewController here.
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"toSingleWebView"]) {
SingleWebViewController *singleWebViewController = segue.destinationViewController;
NSIndexPath *indexPath = [self.tableView indexPathOfSelectedRow];
if(indexpath.row == 0){
singleWebViewController.resourceName=#"intro";
}
else if(indexPath.row == 1){
singleWebViewController.resourceName=#"some other value";
}
else{
singleWebViewController.resourceName=#"something else";
}
NSLog(#"HtmlFileName:%#" , singleWebViewController.resourceName);
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
selectedRow = indexPath.row;
switch (selectedRow)
{
case 0:
{
[self performSegueWithIdentifier:#"toSingleWebView" sender:self];
break;
}
case 1:
{
[self performSegueWithIdentifier:#"toSingleWebView" sender:self];
break;
}
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

Answer 4

You're setting resourceName after viewDidLoad has been called. Add a custom initialiser, initWithResourceName:(NSString *)resourceName, and set it there. Or move the code from viewDidLoad to viewDidAppear:.

Answer 5

Try with:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
HomeViewController *obj = segue.destinationViewController;
if([segue.identifier isEqualToString:#"toSingleWebView"]){
obj.singleWebViewController = singleWebViewController;
}
}