iOS: Wait until user finishes typing and then send request

Question

I have a simple UITableView with UISearchBar/UISearchDisplayController that fetches results from remote ElasticSearch server by using RKObjectManager. Problem I have is that if user types to quickly or the term is a bit bigger several of requests fail and sometimes I don't get the results.

Is there an option to wait until user has stopped typing and then send request instead of sending request per each letter he types in?

score 24 · Accepted Answer · edited Mar 10 '16 at 22:09

24

Add a small delay before sending the request, and then cancel that delayed request if the user continues typing

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    [NSObject cancelPreviousPerformRequestsWithTarget:self];

    [self performSelector:@selector(sendSearchRequest) withObject:searchText afterDelay:0.1f];
}

you may need to adjust the delay time. too long and its noticeable to the user that there is a delay, too short and you have the same problem as now

edited Mar 10 '16 at 22:09

udjat

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answered Jul 01 '14 at 16:38

wattson12

11,176
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34

Any idea how to implement that in swift? – Ram Y May 14 '15 at 13:02
@Ram I've used the answers suggested here as a workaround for lack of performSelector in swift: http://stackoverflow.com/questions/24170282/swift-performselector-withobject-afterdelay – wattson12 May 15 '15 at 09:20

score 8 · Answer 2 · answered Nov 18 '15 at 06:06

8

This is for swift version

NSObject.cancelPreviousPerformRequestsWithTarget(self)
self.performSelector("searchForText:", withObject: searchString, afterDelay: 0.5)

answered Nov 18 '15 at 06:06

Avinash

4,304
1
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18

iOS: Wait until user finishes typing and then send request

2 Answers2

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