NSPredicate Ignore Numbers In String [pinyin] - ios

Question

I've looked around a lot but have been unable to find an answer for this one...
I have a class in my app that contains Chinese Pinyin pronunciation set up as
pronunciation# [space] pronunciation#
for instance 你好[hello] would be
ni3 hao3
so my question is how can I get NSPredicate to ignore the numbers in the string/class during a search?
ideally I would be able to search:
"nihao"
"ni hao"
etc
and still end up with the same result (你好 ni3 hao3)
I've tried out a few LIKE instances but have failed miserably every time...
Thanks
here's my array, as per request:
-(NSMutableArray *) wordList{
cdh = [[NSMutableArray alloc] initWithCapacity:10];
#try {
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSString *dbPath = [[[NSBundle mainBundle] resourcePath ]stringByAppendingPathComponent:#"cdh.sqlite"];
BOOL success = [fileMgr fileExistsAtPath:dbPath];
if(!success)
{
NSLog(#"Cannot locate database file '%#'.", dbPath);
}
if(!(sqlite3_open([dbPath UTF8String], &db) == SQLITE_OK))
{
NSLog(#"An error has occured: %s", sqlite3_errmsg(db));
}
const char *sql = "SELECT * FROM MAIN";
sqlite3_stmt *sqlStatement;
if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK)
{
NSLog(#"Problem with prepare statement: %s", sqlite3_errmsg(db));
}else{
while (sqlite3_step(sqlStatement)==SQLITE_ROW) {
Words * word = [[Words alloc] init];
word.head = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,0)];
word.pro = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,1)];
word.def = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,2)];
[cdh addObject:word];
}
}
sqlite3_finalize(sqlStatement);
}
#catch (NSException *exception) {
NSLog(#"Problem with prepare statement: %s", sqlite3_errmsg(db));
}
#finally {
sqlite3_close(db);
return cdh;
}
}
Words.h
#import <Foundation/Foundation.h>
#import "TestViewController.h"
#interface Words : NSObject {
NSString *head;
NSString *pro;
NSString *def;
}
#property(nonatomic, copy) NSString *head;
#property(nonatomic, copy) NSString *pro;
#property(nonatomic, copy) NSString *def;
#end
Words.m
#import "Words.h"
#implementation Words
#synthesize head;
#synthesize pro;
#synthesize def;
- (NSString *)searchableStringValue {
NSCharacterSet *invalidSet = [[NSCharacterSet characterSetWithCharactersInString:#"[]0123456789 "] invertedSet];
NSString *searchString = [[pro componentsSeparatedByCharactersInSet:invalidSet] componentsJoinedByString:#""];
return searchString;
}
#end
TestViewController.h
#import <UIKit/UIKit.h>
#import <sqlite3.h>
#import "Words.h"
#interface TestViewController : UITableViewController {
NSMutableArray *cdh;
sqlite3 * db;
}
#property(nonatomic,retain) NSMutableArray *cdh;
#property (nonatomic, strong) NSData *myData;
-(NSMutableArray *) wordList;
#end
TestViewController.m (inc. predicate)
- (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope
{
NSPredicate *resultPredicate = [NSPredicate predicateWithFormat:#"(head beginswith[c] %#) OR (searchableStringValue beginswith[c] %#)", searchText, searchText];
searchResults = [cdh filteredArrayUsingPredicate:resultPredicate];
}
-(BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[self filterContentForSearchText:searchString
scope:[[self.searchDisplayController.searchBar scopeButtonTitles]
objectAtIndex:[self.searchDisplayController.searchBar
selectedScopeButtonIndex]]];
return YES;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
//#warning Incomplete method implementation.
// Return the number of rows in the section.
if (tableView == self.searchDisplayController.searchResultsTableView) {
return [searchResults count];
} else {
return [self.cdh count];
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
//UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// int rowCount = indexPath.row;
// Words *word = [self.cdh objectAtIndex:rowCount];
// cell.textLabel.text = word.head;
// cell.detailTextLabel.text = [NSString stringWithFormat:#"%# %#", word.pro, word.def];
// Configure the cell...
Words *word = nil;
if (tableView == self.searchDisplayController.searchResultsTableView) {
word = [searchResults objectAtIndex:indexPath.row];
} else {
word = [cdh objectAtIndex:indexPath.row];
}
cell.textLabel.text = word.head;
cell.detailTextLabel.text = [NSString stringWithFormat:#"%# %#", word.pro, word.def];
return cell;
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"ShowWordDetails"]) {
NSIndexPath *indexPath = nil;
Words *word = nil;
if (self.searchDisplayController.active) {
indexPath = [self.searchDisplayController.searchResultsTableView indexPathForSelectedRow];
word = [searchResults objectAtIndex:indexPath.row];
} else {
indexPath = [self.tableView indexPathForSelectedRow];
word = [cdh objectAtIndex:indexPath.row];
}
DetailsViewController *destViewController = segue.destinationViewController;
destViewController.word = word;
}
}

Answer 1

Your strings are contained in a Words class. This gives you a perfect opportunity to create additional methods to help out with processing the strings it holds (i.e. you don't need to try doing everything in the predicate).
For instance, consider adding a method which returns:
- (NSString *)searchableStringValue
this method would take the string that you are currently trying to search and mutate it to remove the brackets, numbers, spaces. This can most easily be achieved with:
NSCharacterSet *invalidSet = [[NSCharacterSet characterSetWithCharactersInString:#"[]0123456789 "] invertedSet];
NSString *searchString = [[##XXX## componentsSeparatedByCharactersInSet:invalidSet] componentsJoinedByString:#""];
where ##XXX## is the string that you are currently trying to search.
Now, your predicate should use searchableStringValue, instead of the string that you are currently trying to search.