NSOperations or NSThread for bursts of smaller tasks that continuously cancel each other?
- by RickiG
Hi
I would like to see if I can make a "search as you type" implementation, against a web service, that is optimized enough for it to run on an iPhone.
The idea is that the user starts typing a word; "Foo", after each new letter I wait XXX ms. to see if they type another letter, if they don't, I call the web service using the word as a parameter.
The web service call and the subsequent parsing of the result I would like to move to a different thread.
I have written a simple SearchWebService class, it has only one public method:
- (void) searchFor:(NSString*) str;
This method tests if a search is already in progress (the user has had a XXX ms. delay in their typing) and subsequently stops that search and starts a new one. When a result is ready a delegate method is called:
- (NSArray*) resultsReady;
I can't figure out how to get this functionality 'threaded'.
If I keep spawning new threads each time a user has a XXX ms. delay in the typing I end up in a bad spot with many threads, especially because I don't need any other search, but the last one.
Instead of spawning threads continuously, I have tried keeping one thread running in the background all the time by:
- (void) keepRunning {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
SearchWebService *searchObj = [[SearchWebService alloc] init];
[[NSRunLoop currentRunLoop] run]; //keeps it alive
[searchObj release];
[pool release];
}
But I can't figure out how to access the "searchFor" method in the "searchObj" object, so the above code works and keeps running. I just can't message the searchObj or retrieve the resultReady objects?
Hope someone could point me in the right direction, threading is giving me grief:)
Thank you.
