UIWebView Delegate : webViewDidFinishLoad not being called

Question

I try to load an array of UIWebView with delegate associated.

for (GDataXMLElement *post in array) {
    NSString *msg = [[[post elementsForName:@"message"] objectAtIndex:0] stringValue];
    UIWebView *web_view = [[UIWebView alloc] initWithFrame:CGRectZero];
    web_view.delegate = self;
    [web_view loadHTMLString:msg baseURL:nil];
    NSLog(@"Msg: %@", msg);
}

where msg is some HTML codes reading from XML. XML is loaded properly (verified by the NSLog line). Then in my webViewDidFinishLoad::

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    CGRect frame = webView.frame;
    frame.size.height = 1;
    webView.frame = frame;
    CGSize fittingSize = [webView sizeThatFits:CGSizeZero];
    frame.size = fittingSize;
    webView.frame = frame;
    NSLog(@"WebView Height: %.1f", webView.frame.size.height);

    [webviews addObject:webView];
}

I auto resize the web views and add them to a NSMutableArray called webviews. However, webViewDidFinishLoad is not called.

In the header .h file, the interface is defined as:

@interface ViewController : UIViewController<UIWebViewDelegate>

What did I miss? Is the web_view in the loop get disposed ?

p.s. It looks like a duplicate of this question, but it isn't.

---

Alternate Approach 1

Declared at .h:

@property (nonatomic, weak) NSMutableArray *webviews;

Then for implementation:

for (GDataXMLElement *post in array) {
    NSString *msg = [[[post elementsForName:@"message"] objectAtIndex:0] stringValue];
    UIWebView *web_view = [[UIWebView alloc] initWithFrame:CGRectZero];
    web_view.delegate = self;
    [web_view loadHTMLString:msg baseURL:nil];
    NSLog(@"Msg: %@", msg);
    [self.webviews addObject:web_view];
}
- (void)webViewDidFinishLoad:(UIWebView *)webView {
    CGRect frame = webView.frame;
    frame.size.height = 1;
    webView.frame = frame;
    CGSize fittingSize = [webView sizeThatFits:CGSizeZero];
    frame.size = fittingSize;
    webView.frame = frame;
    NSLog(@"WebView Height: %.1f", webView.frame.size.height);
}

---

Alternate Approach 2

Instead of instantiating UIWebView in for-loop, I put it in header file.

@interface ViewController : UIViewController<UIWebViewDelegate> {
    UIWebView *web_view;
}

Then change the for-loop:

for (GDataXMLElement *post in array) {
    NSString *msg = [[[post elementsForName:@"message"] objectAtIndex:0] stringValue];
    web_view = [[UIWebView alloc] initWithFrame:CGRectZero];
    web_view.delegate = self;
    [web_view loadHTMLString:msg baseURL:nil];
    NSLog(@"Msg: %@", msg);
    [self.webviews addObject:web_view];
}

In this approach, only the delegate of last message gets called.

---

Summary & Highlights:

My objectives:

1. Load all UIWebView with variable-size contents
2. The web views should auto fit the size of contents ( without scrolling ); that's why webViewDidFinishLoad is required.
3. Arrange the web views properly on current view ( or probably a UIScrollView ) in order to make it not overlapped.

Answer 1

You should do like this,

@interface UIViewController <UIWebViewDelegate>
{

}
@property(nonatomic, strong)NSMutableArray *webViews;

@end

////////////////

@implementation UIViewController

-(void)viewDidLoad
{
  [super viewDidLoad];

   webViews = [[NSMutableArray alloc] init];

   for (GDataXMLElement *post in array) 
   {
    NSString *msg = [[[post elementsForName:@"message"] objectAtIndex:0] stringValue];
    UIWebView *web_view = [[UIWebView alloc] initWithFrame:CGRectZero];
    web_view.delegate = self;
    [web_view loadHTMLString:msg baseURL:nil];
    NSLog(@"Msg: %@", msg);
    [self.webViews addObject:web_view];

     //i don't know why would  you not add these web-views on the view controller,
     // but still, here is the addition of these.
     [self.view addSubView:web_view];
    }
}

@end

This should make the web-views call the delegate properly on load.

Answer 2

If you're using ARC, the web_view is deallocated at the end of the for loop.

Answer 3

Here is my final solution ( hope it is useful for others ):

In Storyboard, I added a UIScrollView in the view controller, and link it with the IBOutlet.

Header file:

#import <UIKit/UIKit.h>
#import "GDataXMLNode.h"

@interface ViewController : UIViewController<UIWebViewDelegate> {
    IBOutlet UIScrollView *scroll_view;
}
@property (nonatomic, strong) UIWebView *web_view;

@end

Implementation file:

float currentY;
NSArray *array;
int count;
GDataXMLDocument *doc;

- (void)viewDidLoad
{
    [super viewDidLoad];

    currentY = 0;
    count = 0;
    [self loadXML];
}

- (void)loadXML {
   // Some codes to load the XML contents into array variable
   [self loadWebView];
}

- (void)loadWebView {
    if(count < array.count) {
        GDataXMLElement *post = [array objectAtIndex:count];
        NSString *msg = [[[post elementsForName:@"message"] objectAtIndex:0] stringValue];
        count++;
        self.web_view = [[UIWebView alloc] initWithFrame:CGRectMake(10, currentY, 300, 1.0f)];
        self.web_view.delegate = self;
        [self.web_view setHidden:YES];
        [self.web_view loadHTMLString:msg baseURL:nil];
        [scroll_view addSubview:self.web_view];
    } else {
        // end the process
        [scroll_view setContentSize:CGSizeMake(320, currentY + 30)];
        return;
    }
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    CGRect frame = webView.frame;
    frame.size.height = 1;
    webView.frame = frame;
    CGSize fittingSize = [webView sizeThatFits:CGSizeZero];
    frame.size = fittingSize;
    webView.frame = frame;
    [webView setHidden:NO];

    currentY += webView.frame.size.height + 20.0f; // 20.0f is spaces between posts

    NSLog(@"WebView Height: %.1f", webView.frame.size.height);
    [self loadWebView];
}