How can i implement UIActivityIndicatorView during performing search functionality? - ios

Question

I’m building an article reading app.I’m fetching the data from server in JSON format and load into UITableViewController.In search part when user
enter something for a search it will take time to load data into a UITableView.I’m unable to implement UIActivityIndicatorView in between the time search result takes to load
data in UITableViewController.
Here is my Code:
-(void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
NSString *searchText=searchBar.text;
[self.mySearchBar resignFirstResponder];
NSString *trimmedString = [searchText stringByTrimmingCharactersInSet:
[NSCharacterSet whitespaceCharacterSet]];
if (trimmedString.length==0) {
isFilter=NO;
UIAlertView *noConn = [[UIAlertView alloc] initWithTitle:#"ERROR" message:#"Please enter your something in search bar" delegate:self cancelButtonTitle:nil otherButtonTitles:#"ok", nil];
[noConn show];
}
else
NSString *searchNew = [trimmedString stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
isFilter=YES;
#try {
[label removeFromSuperview];
_Title1 = [[NSMutableArray alloc] init];
_Author1 = [[NSMutableArray alloc] init];
_Images1 = [[NSMutableArray alloc] init];
_Details1 = [[NSMutableArray alloc] init];
_link1 = [[NSMutableArray alloc] init];
_Date1 = [[NSMutableArray alloc] init];
NSString* myURLString = [NSString stringWithFormat:#“www.example.com&search=%#", searchNew];
NSURL *url = [NSURL URLWithString:myURLString];
NSData* data = [NSData dataWithContentsOfURL:url];
if ((unsigned long)data.length > 3)
{
NSArray *ys_avatars = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
if(ys_avatars){
for (int j=0;j<ys_avatars.count;j++)
{
[_Title1 addObject:ys_avatars[j][#"title"]];
[_Author1 addObject: ys_avatars[j][#"author"]];
[_Images1 addObject: ys_avatars[j][#"featured_img"]];
[_Details1 addObject:ys_avatars[j][#"content"]];
[_link1 addObject:ys_avatars[j][#"permalink"]];
NSString *newStr=[ys_avatars[j][#"date"] substringToIndex:[ys_avatars[j] [#"date"] length]-3];
[_Date1 addObject:newStr];
}
}
else
{
NSLog(#"error");
}
[self.myTableView reloadData];
}
}
else{
[self.myTableView reloadData];
self.tableView.separatorColor = [UIColor colorWithRed:255/255.0 green:255/255.0 blue:255/255.0 alpha:1.0];
label = [[UILabel alloc] initWithFrame:CGRectMake(90, 100, 200, 100)];
label.text=#"No Article Found";
label.backgroundColor = [UIColor clearColor];
[self.view addSubview:label];
}
}
#catch (NSException *exception) {
}
}
}

Answer 1

you can do this right after the searchBarSearchButton is clicked.
then you add this line inside the cellForRowAtIndexPath:
-(void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
[_activityIndicator startAnimating];
your code
}
next:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexpath.row == [your_array_of_content count]-1)
{
[_activityIndicator stopAnimating];
}
}

Answer 2

dataWithContentsOfURL is a synchronous API. One way to achieve what you want is to use NSURLConnection APIs to load the date from an URL asynchronously. You should also be hooking into the below listed delegate methods to start and stop the activity indicator.
connection:didReceiveResponse:
connectionDidFinishLoading:
I would also like to suggest you to use libraries like AFNetworking which will give you the before and after hooks as callback blocks, which will be little cleaner on the coding front.

Answer 3

Create the indicator:
UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:
UIActivityIndicatorViewStyleWhiteLarge];
[activityIndicator setCenter:CGPointMake(view.frame.size.width/2.0, view.frame.size.height/2.0)];
activityIndicator.hidesWhenStopped = YES;
activityIndicator.color = [UIColor blackColor];
//add it to the view
[self.view addSubview:activityIndicator];
//start the animation
[activityIndicator startAnimating];
and when you want to dismiss it:
[activityIndicator stopAnimating];