UISearchDisplayContoller – can't prevent table reload on typing in search bar

http://stackoverflow.com/questions/3903718/uisearchdisplaycontoller-cant-prevent-table-reload-on-typing-in-search-bar/5342989#5342989

This is just the way UISearchDisplayController (SDC) works. When the user enters the first character into the searchBar the searchTable is loaded and displayed for the first time causing it to load. The methods "...shouldReloadTableForSearchString" and "...shouldReloadTableForSearchScope"
allow you to control whether the searchTable reloads automatically on subsequent chars or a scope change.

I've done both of the following to provide a good user experience on the first character. Slight disclaimer: I do have implementations of both of these that work but this is simply a framework for implementation from my memory. I may have missed a detail
but this should get you pretty close.

Option 1: Present a "loading" cell in the searchTable when the first char is typed.

This option allows the SDC to display the searchResultsTableView when the user types the first char, display status as to the current search/filter operation

in the SDC delegate class definition

add the iVar

BOOL isLoading

add the iVar

UITableView *searchTableView

in

searchDisplayController:didLoadSearchResultsTableView

set

searchTableView = tableView

in

shouldReloadTableForSearchString/Scope

set

isLoading = YES

call your method to load data in the background
return NO

when your background filter is complete:

set

isLoading = NO

[searchTableView reloadData]

in the various tableView delegate methods respond how you like to show status if there are current search results or results are loading in the background. What I did is:

if there are current search results, show results (even if loading/filtering in the background)
if there are no search results and

isLoading == NO

return 1 row and show 'No matches' in a cell
if there are no search results and

isLoading == YES

return 1 row and and show search activity in a cell (I typically use UIActivityIndicatorView)

Option 2: Hide the searchTableView and display an overlay view in it's place until search results are loaded

This option hides the searchTableView when it is first loaded and only redisplays it if when the search/filter is complete. I defined this as an add on to option 1 as they can be done together though to optimize things you may not care about showing search
activity in the searchResultsTableView if you are hiding the table and showing the overlay.

in the SDC delegate class definition

same as Option 1
add the iVar

UIView *searchTableOverlayView

in

searchDisplayController:didLoadSearchResultsTableView

same as Option 1
create a UIView to use as an overlay in place of searchTableView containing whatever UI is appropriate for your app and set it to

searchTableOverlayView

in

searchDisplayController:didUnloadSearchResultsTableView

release

searchTableOverlayView

in 'searchDisplayController:didShowSearchResultsTableView

(may be able to do this in

searchDisplayController:willShowSearchResultsTableView`

if there are search results to display or

isLoading == NO

seachTableOverlayView.hidden == YES

else (if

isLoading == YES

)

searchTableOverlayView.frame == searchResultsTableView.frame

add

seachTableOverlayView

as a subview of

searchTableVIew.superview

searchTableView.hidden = YES

when your background filter is complete

same as option 1
if there are searchResults to display

searchTableCoverView.hidden = YES'</li> <li>

searchResultsTableView.hidden = NO'

else

searchResultsTableView.hidden = YES

searchTableCoverView.hidden = NO

in the various tableView delegate methods respond how you like to show status if there are current search results or results are loading in the background. What I did is:

same as option 1