Method to dynamically set the height of UILabel, UITableViewCell etc

To find the height of a label , UITableViewCell or UITextView for dynamic string content. Following method may help

- (float)getHeightFortheDynamicLabel:(NSString *)stringForTheLabel{
    UITextView *aSampleTextView;
    // 30 is the minimum height
    aSampleTextView = [[UITextView alloc] initWithFrame:CGRectMake(0, 0, mywidth, 30)];
    aSampleTextView.text = stringForTheLabel;
    aSampleTextView.font = [UIFont systemFontOfSize:kMyFontSize];
    aSampleTextView.alpha = 0;
    [self.view addSubview:aSampleTextView];
    float textViewHeight = aSampleTextView.contentSize.height;
    [aSampleTextView removeFromSuperview];
    [aSampleTextView release];
    return  textViewHeight;
}

Programmatically calling to a phone number from iPhone.

//  This method will call a phone number from string.
+ (void)callPhoneNumber:(NSString *)phoneNumberString
{
        if ([phoneNumberString length]>0)
        {
            phoneNumberString = [[phoneNumberString componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] componentsJoinedByString: @""];
            NSString *phoneDecender = @"tel:";
            NSString *totalPhoneNumberString = [phoneDecender stringByAppendingString:phoneNumberString];
            NSURL *aPhoneNumberURL = [NSURL URLWithString:totalPhoneNumberString];
       
            if ([[UIApplication sharedApplication] canOpenURL:aPhoneNumberURL])
            {
                    [[UIApplication sharedApplication] openURL:aPhoneNumberURL];
            }
       
        }
}

Applying Java script to UIWebView from Objective C - iPhone SDK

//------------------------------------------------------------------------------------------------------------ 
/*Java script code */
function switchFontsize(val)
{
    if(val)
    {
         document.getElementById("myDivId").style.fontSize = val + "px";
         document.getElementById("mySecondDivId").style.fontSize = val + "px";
    }
}
//-------------------------------------------------------------------------------------------------------------
/* Objective C function to apply font to the web view */
+ (void)applyFontToWebView:(UIWebView *)webView withFontSize:(int)fontSize
{
    NSString *jsString = [NSString stringWithFormat:@"switchFontsize(%d)",fontSize];
    [webView stringByEvaluatingJavaScriptFromString:jsString];
}
//-------------------------------------------------------------------------------------------------------------
/* Function to call when font plus button press event */
- (void)increaseFont
{
    // 24 is set as the maximum font size.
    if (currentFontSize < 24)
    {
        currentFontSize = currentFontSize + 2;
    }
    [FontClass applyFontToWebView:self.webView withFontSize:currentFontSize];
}

Note - Make sure that you are calling the java script file in the html string loaded in the webview.

Validating UITextView For Minimum Text Length

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{

if (([text length] == 0)&& ([textView.text length] ==1))
{
self.sendButton.enabled = NO;
}
else if ([text length] == 1)
{
self.sendButton.enabled = YES;
}

return YES;
}

NSXMLParserErrorDomain error 68

If you get this kind of parsing error,

NSXMLParserErrorDomain error 68 or called as 'NSXMLParserNAMERequiredError'

Reason :- Most likely, the error is caused because the xml data you are parsing. in the xml there will be some special characters that are not encoded.

Example :- character '&' did not show up as '&amp'

That is what the error means: Parser is expecting an input for that assuming '&' as a element.

Solution :- Change the xml.

For more details :- NSXMLParser Class Reference

Thanks

Creating a POST request and downloading the data. - iOS SDK

NetCommunicator.m

@implementation NetCommunicator

@synthesize myFeedConnection,myReceivedData;

-(void)createPostRequestWith:(NSString *)username andPassword:(NSString *)password {

NSString *post = [NSString stringWithFormat:@"username=%@&password=%@",username,password];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:@"www.yourwebpage.com"]];

[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData];

self.myFeedConnection = [[[NSURLConnection alloc] initWithRequest:request delegate:self] autorelease];

// Test the validity of the connection object. The most likely reason for the connection object
// to be nil is a malformed URL, which is a programmatic error easily detected during development
// If the URL is more dynamic, then you should implement a more flexible validation technique, and
// be able to both recover from errors and communicate problems to the user in an unobtrusive manner.
//

NSAssert(self.myFeedConnection != nil, @"Failure to create URL connection.");

// show in the status bar that network activity is starting
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
}



#pragma mark -
#pragma mark NSURL Connection Delegate

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {

if (connection == self.myFeedConnection) {
self.myReceivedData = [NSMutableData data];
}

}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {

if (connection == self.myFeedConnection) {

[self.myReceivedData appendData:data];
}

}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

if (connection == self.myFeedConnection) {
if ([error code] == kCFURLErrorNotConnectedToInternet)
{
// if we can identify the error, we can present a more precise message to the user.
NSDictionary *userInfo = [NSDictionary dictionaryWithObject:@"No Connection Error"
forKey:NSLocalizedDescriptionKey];
NSError *noConnectionError = [NSError errorWithDomain:NSCocoaErrorDomain
code:kCFURLErrorNotConnectedToInternet
userInfo:userInfo];
[self handleError:noConnectionError];
}
else
{
// otherwise handle the error generically
[self handleError:error];
}
// release our connection
self.myFeedConnection = nil;
}

}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

if(connection == self.myFeedConnection) {

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

NSLog(@"my Data: %.*s", [self.myReceivedData length], [self.myReceivedData bytes]);

// Do the rest with the downloaded data.

self.myFeedConnection = nil;

}

}


// -------------------------------------------------------------------------------
// handleError:error // This method should be modified ..
// -------------------------------------------------------------------------------
- (void)handleError:(NSError *)error
{
NSString *errorMessage = [error localizedDescription];
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Cannot download"
message:errorMessage
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil];
[alertView show];
[alertView release];
}


@end