/* |
Copyright (C) 2015 Apple Inc. All Rights Reserved. |
See LICENSE.txt for this sample’s licensing information |
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Abstract: |
The application's primary table view controller showing a list of products. |
*/ |
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#import "APLMainTableViewController.h" |
#import "APLDetailViewController.h" |
#import "APLResultsTableController.h" |
#import "APLProduct.h" |
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@interface APLMainTableViewController () <UISearchBarDelegate, UISearchControllerDelegate, UISearchResultsUpdating> |
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@property (nonatomic, strong) UISearchController *searchController; |
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// our secondary search results table view |
@property (nonatomic, strong) APLResultsTableController *resultsTableController; |
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// for state restoration |
@property BOOL searchControllerWasActive; |
@property BOOL searchControllerSearchFieldWasFirstResponder; |
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@end |
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#pragma mark - |
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@implementation APLMainTableViewController |
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- (void)viewDidLoad { |
[super viewDidLoad]; |
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_resultsTableController = [[APLResultsTableController alloc] init]; |
_searchController = [[UISearchController alloc] initWithSearchResultsController:self.resultsTableController]; |
self.searchController.searchResultsUpdater = self; |
[self.searchController.searchBar sizeToFit]; |
self.tableView.tableHeaderView = self.searchController.searchBar; |
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// we want to be the delegate for our filtered table so didSelectRowAtIndexPath is called for both tables |
self.resultsTableController.tableView.delegate = self; |
self.searchController.delegate = self; |
self.searchController.dimsBackgroundDuringPresentation = NO; // default is YES |
self.searchController.searchBar.delegate = self; // so we can monitor text changes + others |
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// Search is now just presenting a view controller. As such, normal view controller |
// presentation semantics apply. Namely that presentation will walk up the view controller |
// hierarchy until it finds the root view controller or one that defines a presentation context. |
// |
self.definesPresentationContext = YES; // know where you want UISearchController to be displayed |
} |
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- (void)viewDidAppear:(BOOL)animated { |
[super viewDidAppear:animated]; |
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// restore the searchController's active state |
if (self.searchControllerWasActive) { |
self.searchController.active = self.searchControllerWasActive; |
_searchControllerWasActive = NO; |
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if (self.searchControllerSearchFieldWasFirstResponder) { |
[self.searchController.searchBar becomeFirstResponder]; |
_searchControllerSearchFieldWasFirstResponder = NO; |
} |
} |
} |
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#pragma mark - UISearchBarDelegate |
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- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar { |
[searchBar resignFirstResponder]; |
} |
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#pragma mark - UISearchControllerDelegate |
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// Called after the search controller's search bar has agreed to begin editing or when |
// 'active' is set to YES. |
// If you choose not to present the controller yourself or do not implement this method, |
// a default presentation is performed on your behalf. |
// |
// Implement this method if the default presentation is not adequate for your purposes. |
// |
- (void)presentSearchController:(UISearchController *)searchController { |
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} |
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- (void)willPresentSearchController:(UISearchController *)searchController { |
// do something before the search controller is presented |
} |
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- (void)didPresentSearchController:(UISearchController *)searchController { |
// do something after the search controller is presented |
} |
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- (void)willDismissSearchController:(UISearchController *)searchController { |
// do something before the search controller is dismissed |
} |
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- (void)didDismissSearchController:(UISearchController *)searchController { |
// do something after the search controller is dismissed |
} |
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#pragma mark - UITableViewDelegate |
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- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { |
return self.products.count; |
} |
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- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { |
UITableViewCell *cell = (UITableViewCell *)[self.tableView dequeueReusableCellWithIdentifier:kCellIdentifier forIndexPath:indexPath]; |
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APLProduct *product = self.products[indexPath.row]; |
[self configureCell:cell forProduct:product]; |
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return cell; |
} |
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// here we are the table view delegate for both our main table and filtered table, so we can |
// push from the current navigation controller (resultsTableController's parent view controller |
// is not this UINavigationController) |
// |
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { |
APLProduct *selectedProduct = (tableView == self.tableView) ? |
self.products[indexPath.row] : self.resultsTableController.filteredProducts[indexPath.row]; |
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APLDetailViewController *detailViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"APLDetailViewController"]; |
detailViewController.product = selectedProduct; // hand off the current product to the detail view controller |
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[self.navigationController pushViewController:detailViewController animated:YES]; |
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// note: should not be necessary but current iOS 8.0 bug (seed 4) requires it |
[tableView deselectRowAtIndexPath:indexPath animated:NO]; |
} |
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#pragma mark - UISearchResultsUpdating |
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- (void)updateSearchResultsForSearchController:(UISearchController *)searchController { |
// update the filtered array based on the search text |
NSString *searchText = searchController.searchBar.text; |
NSMutableArray *searchResults = [self.products mutableCopy]; |
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// strip out all the leading and trailing spaces |
NSString *strippedString = [searchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]; |
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// break up the search terms (separated by spaces) |
NSArray *searchItems = nil; |
if (strippedString.length > 0) { |
searchItems = [strippedString componentsSeparatedByString:@" "]; |
} |
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// build all the "AND" expressions for each value in the searchString |
// |
NSMutableArray *andMatchPredicates = [NSMutableArray array]; |
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for (NSString *searchString in searchItems) { |
// each searchString creates an OR predicate for: name, yearIntroduced, introPrice |
// |
// example if searchItems contains "iphone 599 2007": |
// name CONTAINS[c] "iphone" |
// name CONTAINS[c] "599", yearIntroduced ==[c] 599, introPrice ==[c] 599 |
// name CONTAINS[c] "2007", yearIntroduced ==[c] 2007, introPrice ==[c] 2007 |
// |
NSMutableArray *searchItemsPredicate = [NSMutableArray array]; |
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// Below we use NSExpression represent expressions in our predicates. |
// NSPredicate is made up of smaller, atomic parts: two NSExpressions (a left-hand value and a right-hand value) |
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// name field matching |
NSExpression *lhs = [NSExpression expressionForKeyPath:@"title"]; |
NSExpression *rhs = [NSExpression expressionForConstantValue:searchString]; |
NSPredicate *finalPredicate = [NSComparisonPredicate |
predicateWithLeftExpression:lhs |
rightExpression:rhs |
modifier:NSDirectPredicateModifier |
type:NSContainsPredicateOperatorType |
options:NSCaseInsensitivePredicateOption]; |
[searchItemsPredicate addObject:finalPredicate]; |
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// yearIntroduced field matching |
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init]; |
[numberFormatter setNumberStyle:NSNumberFormatterNoStyle]; |
NSNumber *targetNumber = [numberFormatter numberFromString:searchString]; |
if (targetNumber != nil) { // searchString may not convert to a number |
lhs = [NSExpression expressionForKeyPath:@"yearIntroduced"]; |
rhs = [NSExpression expressionForConstantValue:targetNumber]; |
finalPredicate = [NSComparisonPredicate |
predicateWithLeftExpression:lhs |
rightExpression:rhs |
modifier:NSDirectPredicateModifier |
type:NSEqualToPredicateOperatorType |
options:NSCaseInsensitivePredicateOption]; |
[searchItemsPredicate addObject:finalPredicate]; |
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// price field matching |
lhs = [NSExpression expressionForKeyPath:@"introPrice"]; |
rhs = [NSExpression expressionForConstantValue:targetNumber]; |
finalPredicate = [NSComparisonPredicate |
predicateWithLeftExpression:lhs |
rightExpression:rhs |
modifier:NSDirectPredicateModifier |
type:NSEqualToPredicateOperatorType |
options:NSCaseInsensitivePredicateOption]; |
[searchItemsPredicate addObject:finalPredicate]; |
} |
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// at this OR predicate to our master AND predicate |
NSCompoundPredicate *orMatchPredicates = [NSCompoundPredicate orPredicateWithSubpredicates:searchItemsPredicate]; |
[andMatchPredicates addObject:orMatchPredicates]; |
} |
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// match up the fields of the Product object |
NSCompoundPredicate *finalCompoundPredicate = |
[NSCompoundPredicate andPredicateWithSubpredicates:andMatchPredicates]; |
searchResults = [[searchResults filteredArrayUsingPredicate:finalCompoundPredicate] mutableCopy]; |
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// hand over the filtered results to our search results table |
APLResultsTableController *tableController = (APLResultsTableController *)self.searchController.searchResultsController; |
tableController.filteredProducts = searchResults; |
[tableController.tableView reloadData]; |
} |
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#pragma mark - UIStateRestoration |
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// we restore several items for state restoration: |
// 1) Search controller's active state, |
// 2) search text, |
// 3) first responder |
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NSString *const ViewControllerTitleKey = @"ViewControllerTitleKey"; |
NSString *const SearchControllerIsActiveKey = @"SearchControllerIsActiveKey"; |
NSString *const SearchBarTextKey = @"SearchBarTextKey"; |
NSString *const SearchBarIsFirstResponderKey = @"SearchBarIsFirstResponderKey"; |
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- (void)encodeRestorableStateWithCoder:(NSCoder *)coder { |
[super encodeRestorableStateWithCoder:coder]; |
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// encode the view state so it can be restored later |
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// encode the title |
[coder encodeObject:self.title forKey:ViewControllerTitleKey]; |
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UISearchController *searchController = self.searchController; |
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// encode the search controller's active state |
BOOL searchDisplayControllerIsActive = searchController.isActive; |
[coder encodeBool:searchDisplayControllerIsActive forKey:SearchControllerIsActiveKey]; |
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// encode the first responser status |
if (searchDisplayControllerIsActive) { |
[coder encodeBool:[searchController.searchBar isFirstResponder] forKey:SearchBarIsFirstResponderKey]; |
} |
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// encode the search bar text |
[coder encodeObject:searchController.searchBar.text forKey:SearchBarTextKey]; |
} |
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- (void)decodeRestorableStateWithCoder:(NSCoder *)coder { |
[super decodeRestorableStateWithCoder:coder]; |
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// restore the title |
self.title = [coder decodeObjectForKey:ViewControllerTitleKey]; |
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// restore the active state: |
// we can't make the searchController active here since it's not part of the view |
// hierarchy yet, instead we do it in viewWillAppear |
// |
_searchControllerWasActive = [coder decodeBoolForKey:SearchControllerIsActiveKey]; |
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// restore the first responder status: |
// we can't make the searchController first responder here since it's not part of the view |
// hierarchy yet, instead we do it in viewWillAppear |
// |
_searchControllerSearchFieldWasFirstResponder = [coder decodeBoolForKey:SearchBarIsFirstResponderKey]; |
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// restore the text in the search field |
self.searchController.searchBar.text = [coder decodeObjectForKey:SearchBarTextKey]; |
} |
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@end |
