How to Use the Uisearchbar and Uisearchdisplaycontroller

How do I use the UISearchBar and UISearchDisplayController

• First add the UISearchDisplayController to your table view
• Then set its delegate.
• Implement the following methods.

Demo Project

In your .h File

    @interface ViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {

    NSMutableArray *contentList;
    NSMutableArray *filteredContentList;
    BOOL isSearching;
}
@property (strong, nonatomic) IBOutlet UITableView *tblContentList;
@property (strong, nonatomic) IBOutlet UISearchBar *searchBar;
@property (strong, nonatomic) IBOutlet UISearchDisplayController *searchBarController;

In your .m File

Filling the sample data (Optional Only For Demo Purpose)

- (void)viewDidLoad {
    [super viewDidLoad];
    contentList = [[NSMutableArray alloc] initWithObjects:@"iPhone", @"iPod", @"iPod touch", @"iMac", @"Mac Pro", @"iBook",@"MacBook", @"MacBook Pro", @"PowerBook", nil];
    filteredContentList = [[NSMutableArray alloc] init];
}

Now implement the Table View Delegate and Datasource

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    if (isSearching) {
        return [filteredContentList count];
    }
    else {
        return [contentList count];
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    // Configure the cell...
    if (isSearching) {
        cell.textLabel.text = [filteredContentList objectAtIndex:indexPath.row];
    }
    else {
        cell.textLabel.text = [contentList objectAtIndex:indexPath.row];
    }
    return cell;

}

Search Function Responsible For Searching

- (void)searchTableList {
    NSString *searchString = searchBar.text;

    for (NSString *tempStr in contentList) {
        NSComparisonResult result = [tempStr compare:searchString options:(NSCaseInsensitiveSearch|NSDiacriticInsensitiveSearch) range:NSMakeRange(0, [searchString length])];
        if (result == NSOrderedSame) {
            [filteredContentList addObject:tempStr];
        }
    }
}

Search Bar Implementation

- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar {
    isSearching = YES;
}

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText {
    NSLog(@"Text change - %d",isSearching);

    //Remove all objects first.
    [filteredContentList removeAllObjects];

    if([searchText length] != 0) {
        isSearching = YES;
        [self searchTableList];
    }
    else {
        isSearching = NO;
    }
    // [self.tblContentList reloadData];
}

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar {
    NSLog(@"Cancel clicked");
}

- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar {
    NSLog(@"Search Clicked");
    [self searchTableList];
}

How UISearchDisplayController steals UISearchBar events

OK, I figured out myself.

You can do that just by adding the UISearchBar delegate property to KVO observation, and then make your implementation as a delegate proxy.

Example Code:

---

    if (searchBar.delegate) {
        self.searchBarDelegate = searchBar.delegate;
    }

    searchBar.delegate = self;

    [searchBar addObserver:self forKeyPath:@"delegate" options:NSKeyValueObservingOptionNew context:kSearchBarKVOContext];

---

#pragma mark - KVO
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if (context == kSearchBarKVOContext) {
        [self updateSearchBarDelegate];
    } else {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

---

- (void)updateSearchBarDelegate
{
    if (self.searchBar.delegate == self) {
        self.searchBarDelegate = nil;
    } else {
        self.searchBarDelegate = self.searchBar.delegate;
        self.searchBar.delegate = self;
    }
}

---

#pragma mark - NSObject Overrides
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
{
    NSMethodSignature *result = [super methodSignatureForSelector:aSelector];

    if (!result) {
        NSObject *obj = (NSObject *)self.searchBarDelegate;

        result = [obj methodSignatureForSelector:aSelector];
    }

    return result;
}

- (void)forwardInvocation:(NSInvocation *)anInvocation
{
    if ([self.searchBarDelegate respondsToSelector:[anInvocation selector]]) {
        [anInvocation invokeWithTarget:self.searchBarDelegate];
    } else {
        [super forwardInvocation:anInvocation];
    }
}

- (BOOL)respondsToSelector:(SEL)aSelector {
    return ([super respondsToSelector:aSelector] ||
            [self.searchBarDelegate respondsToSelector:aSelector]);
}

How to use UISearchDisplayController from a controller within an UITabBar controller?

Ok, I have found how to solve it. In my case, the problem was due to the fact that I was using a controller embedded within the UITabBarController as one of its managed tabs (i.e. as a child).

Removing the controller from the UITabBarController, then adding an UINavigationController to the UITabBarController instead, and finally putting my controller as a child of the UINavigationController solved completely the issue.

I do not understand why this is so (there is no related information in the documentation, as often happens); however, it now works like a charm.
With kind regards.

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