Why?

I needed a way to present a searchable list of items that come from a (likely) asynchronous source (such as querying a web backend.) There are many widgets to do this type of thing in web/JS applications, but Googling didn't turn up any pre-built widgets for iOS.

What?

JCAutocompletingSearch allows you to present a search controller that executes queries via its delegate. One likely source of the results would a web backend. Given the asynchronous (and delayed) nature of these types of searches, JCAutocompletingSearch automatically shows a loading indicator when necessary as well as managing out-of-order responses which shouldn't be displayed.

The delegate is required to implement:

• Searching
• Cancel button action
• Result selected action

The delegate can optionally implement methods that:

• Control whether or not to perform a blank search on load
• Control whether or not searches are performed synchronously (synchronous searches won't display the loading indicator cell)
• Control whether or not searches are delayed/batched--that is, the search controller can wait to perform searches until the search field hasn't changed for a configurable delay.
• Control whether or not the search view controller should auto rotate to a new device orientation
• Give the ability to present results in custom UITableView cells

Example Code?

A working sample iOS Xcode project is available in the Demo directory.

Usage?

#import "JCAutocompletingSearchViewControllerDelegate.h"

@interface MySearchDelegate : NSObject <JCAutocompletingSearchViewControllerDelegate>
@end

#import "JCAutocompletingSearchViewController.h"

@implementation MySearchDelegate

- (void) searchController:(JCAutocompletingSearchViewController*)searchController
    performSearchForQuery:(NSString*)query
       withResultsHandler:(JCAutocompletingSearchResultsHandler)resultsHandler {
  resultsHandler(@[
    @{@"label": @"Result 1"},
    @{@"label": @"Result 2"},
    @{@"label": @"Result 3"}
  ]);
}

- (void) searchControllerCanceled:(JCAutocompletingSearchViewController*)searchController {
  // Handle search cancellation.
}

- (void) searchController:(JCAutocompletingSearchViewController*)searchController
                tableView:(UITableView*)tableView
           selectedResult:(id)result {
  // Handle search result selection.
}

// Optional.
- (BOOL) searchControllerShouldPerformBlankSearchOnLoad:(JCAutocompletingSearchViewController*)searchController {
  return YES;
}

// Optional.
- (BOOL) searchController:(JCAutocompletingSearchViewController*)searchController shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
  return YES;
}

// Optional.
- (dispatch_time_t) searchControllerDelaySearchingUntilQueryUnchangedForTimeOffset:(JCAutocompletingSearchViewController*)searchController {
  return 0.2 * NSEC_PER_SEC;
}

// Optional.
- (BOOL) searchControllerShouldDisplayNetworkActivityIndicator:(JCAutocompletingSearchViewController*)searchController {
  return YES; // Defaults to YES.
}

// Optional.
- (void) searchController:(JCAutocompletingSearchViewController*)searchController didChangeActivityInProgressToEnabled:(BOOL)activityInProgress {
  NSLog(@"Activity indicator changed to: %@", (activityInProgress ? @"YES" : @"NO"));
}

@end

// ------------------------------------------------------------------------

- (BOOL) application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions {
  self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
  
  JCAutocompletingSearchViewController* searchController = [JCAutocompletingSearchViewController autocompletingSearchViewController];
  searchController.delegate = [MySearchDelegate new];
  
  UINavigationController* navigationController = [[UINavigationController alloc] initWithRootViewController:searchController];
  navigationController.navigationBarHidden = YES;
  self.window.rootViewController = navigationController;
  
  [self.window makeKeyAndVisible];
  return YES;
}

Installation?

This project includes a podspec for usage with CocoaPods. Simply add

pod 'JCAutocompletingSearch'

to your Podfile and run pod install.

Alternately, you can add all of the files contained in this project's Library directory to your Xcode project. If your project does not use ARC, you will need to enable ARC on these files. You can enabled ARC per-file by adding the -fobjc-arc flag, as described on a common StackOverflow question.

License

This project is licensed under the MIT license. All copyright rights are retained by myself.

Copyright (c) 2012 James Coleman

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.