Searching with a UISearchbar is slow and blocking the main thread.
- by Robert
I have a Table with over 3000 entries and searching is very slow.
At the moment I am doing just like in the 'TableSearch' example code (but without scopes)
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[self filterContentForSearchText: searchString];
// Return YES to cause the search result table view to be reloaded.
return YES;
}
And the filterContentForSearchText method is as follows:
- (void) filterContentForSearchText:(NSString*)searchText
{
// Update the filtered array based on the search text
// First clear the filtered array.
[filteredListContent removeAllObjects];
// Search the main list whose name matches searchText
// add items that match to the filtered array.
if (fetchedResultsController.fetchedObjects)
{
for (id object in fetchedResultsController.fetchedObjects)
{
NSString* searchTarget = [tableTypeDelegate getStringForSearchFilteringFromObject:object];
if ([searchTarget rangeOfString:searchText
options:(NSCaseInsensitiveSearch|NSDiacriticInsensitiveSearch)].location != NSNotFound)
{
[filteredListContent addObject:object];
}
}
}
}
My question is twofold:
How do can I make the searching process faster?
How can I stop the search from blocking the main thread? i.e. stop it preventing the user from typing more characters.
For the second part, I tried "performSelector:withObject:afterDelay:" and "cancelPreviousPerformRequests..." without much success. I suspect that I will need to use threading instead, but I do not have much experience with it.
