Setting up a UIWebView delegate

Question

Ok, this should be simple, but for some reason I'm lost.
Primarily, because the different objects are in different modules
and there doesn't seem to be a clean way to tie them together.
I start with a UIView in a simple ViewController.
Next, I want to switch views, by calling a 2nd ViewController. The 2nd controller loads from a nib file, a view with a navbar and a webview. I currently call this from:
// ViewController.h
- (IBAction)showWebView {
AViewController *controller = [[AViewController alloc]
initWithNibName:@"AViewController" bundle:nil];
controller.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:controller animated:YES];
[controller release];
// AViewController.h
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
// Custom initialization
UIWebView* webView = [self myWebView]; // get webview from array of subviews
NSString* path = [[NSBundle mainBundle] pathForResource:@"MyWebPage" ofType:@"html"];
NSURL* fileURL = [[NSURL alloc] initFileURLWithPath:path];
NSURLRequest* req = [NSURLRequest requestWithURL:fileURL];
[webView loadRequest:req];
} // if self = super
return self;
} which sets up a modal view using an animated transition.
The problem is that the UIWebView always starts out with a white screen, which shows white until the webpage is loaded.
Ok, the solution is to use a UIWebViewDelegate. All the examples I see using the delegate say to add the delegate to the webview at load time and then when delegate methodwebViewDidFinishLoadis called, then make the view appear. Ok, I want the modal view to be called AFTER the view is loaded.
So, how do I split up my code to do this? Where do and how do I set the delegate, and where do I put the webViewDidFinishLoad method? (in ViewController, or in AViewController)
If I set the delegate in AViewController in initWithNibName, I would guess the delegate would be something like webView.delegate = self.parentViewController;
but, then I have the issue of how to split up the showWebView method, to create and release the controller properly, and to call presentModalViewController.
What is the proper way to do this? Is there any sample code that does this the approved way?

Answer 1

I believe I understand what you're saying, and I think I may have implemented it the second way, but... my delegate method, webViewDidFinishLoad never gets called. So, some sample code would help.
Here's what I did:
// FlipsideViewController.h
#import "InstructionsViewController.h"
@interface FlipsideViewController : UIViewController <UIWebViewDelegate> {
id <FlipsideViewControllerDelegate> delegate;
InstructionsViewController* instructionsViewController;
@property (nonatomic, assign) id <FlipsideViewControllerDelegate> delegate;
@property (nonatomic, retain) InstructionsViewController* instructionsViewController;
- (IBAction)showInstructions;
@end
// FlipsideViewController.m
@synthesize delegate;
@synthesize instructionsViewController;;
- (IBAction)showInstructions {
instructionsViewController = [[InstructionsViewController alloc]
initWithNibName:@"InstructionsView" bundle:nil];
/* -- commented out, view never shows, if in, issue is the same, view flashes white before load
instructionsViewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:instructionsViewController animated:YES];
[instructionsViewController release];
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
NSLog(@"webView error: %@",[error description]);
// do something here for web page load error
- (void)webViewDidFinishLoad:(UIWebView*)webView {
NSLog(@"Delegate FSV webViewDidFinishLoad");
instructionsViewController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:instructionsViewController animated:YES];
[instructionsViewController release];
// InstructionsViewController.m
#import "InstructionsViewController.h"
#import "FlipsideViewController.h"
@implementation InstructionsViewController
- (UIWebView*)myWebView { // routine in case needed more than once.
NSArray* views = [[NSArray alloc] initWithArray:[self.view subviews]];
NSEnumerator *enumerator = [views objectEnumerator];
id anObject;
while (anObject = [enumerator nextObject]) {
if ( [anObject isKindOfClass:[UIWebView class]] ) {
[views autorelease];
return anObject;
} // if anObject
} // while
[views release];
return nil;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
// Custom initialization
UIWebView* webView;
webView = [self myWebView];
webView.delegate = (FlipsideViewController*)self.parentViewController;
NSString* path = [[NSBundle mainBundle] pathForResource:@"myHTMLfile" ofType:@"html"];
NSURL* fileURL = [[NSURL alloc] initFileURLWithPath:path];
NSURLRequest* req = [NSURLRequest requestWithURL:fileURL];
[webView loadRequest:req];
} // if self = super
return self;
- (void)webViewDidFinishLoad:(UIWebView*)webView {
NSLog(@"Delegate IVC webViewDidFinishLoad");
InstructionsViewController* controller = (InstructionsViewController*) webView.delegate;
controller.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:controller animated:YES];
You may notice that webViewDidFinishLoad appears in BOTH .m files. I put it initially in FlipsideViewController, thinking that is where it belonged, as it was what I thought I set as the delegate. However the routine was never hit, so I tried a copy in the other module. NEITHER gets hit.
Thanks for your help on this one.