Question

I am trying to implement this button action, but the if statement is not evaluating to be true. I have a situation where the value in that “School” dictionary will not always have a website stored. For that reason i want to check, but what do i check against. If “nil” is not stored there when there is not a value, then what is?

 -(IBAction) btnVisitWebsite_clicked :(id)sender {

if([School objectForKey:WEBSITE_KEY] == nil){

    UIAlertView *NoWebsite = [[UIAlertView alloc]initWithTitle: @"No Website"
                                                message:@"The selected school has not listed a website"
                                                delegate:self
                                                cancelButtonTitle:@"OK"
                                                otherButtonTitles:nil];

    NoWebsite.tag = 15;
    [NoWebsite show];
    [NoWebsite release];
    NoWebsite = nil;
}

else{

NSMutableString *WebsiteVisit = [[NSMutableString alloc] initWithString: @"http://"];
[WebsiteVisit appendString:[School objectForKey:WEBSITE_KEY]];

[[UIApplication sharedApplication] openURL:[NSURL URLWithString: WebsiteVisit]];


[WebsiteVisit release];

}
}

Answer 1

If it is possible that the Website is an empty string you should use the following:

if(![School objectForKey:WEBSITE_KEY] 
   || ([[School objectForKey:WEBSITE_KEY] isKindOfClass:[NSString class]] && [(NSString*)[School objectForKey:WEBSITE_KEY] length]==0)){
    // no website
} else { /* has website*/ }