Indexed full-text search

Foxit PDF SDK for iOS provides cross-document indexed full-text search via Core SDK. Build an index over multiple PDFs first, then search quickly—ideal for large document sets.

Core classes

Class	Description
FSFullTextSearch	Full-text search engine: index build and search
FSDocumentsSource	Document source for indexing
FSSearchCallback	Callback per match

Ranking modes

Constant	Description
FSFullTextSearchRankModeNone	No ranking
FSFullTextSearchRankModeHitCount	Rank by hit count

Example: build index and search

Step 1: Create engine and set index database path

#import <FoxitRDK/FSPDFObjC.h>

FSFullTextSearch *fullTextSearch = [[FSFullTextSearch alloc] init];

// Index database path
NSString *dbPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                    NSUserDomainMask, YES).firstObject
                    stringByAppendingPathComponent:@"search_index"];
[fullTextSearch setDataBasePath:dbPath];

Step 2: Build or update index

// Update index for one file
[fullTextSearch updateIndexWithFilePath:@"path/to/Sample.pdf"];

Batch indexing asynchronously:

FSDocumentsSource *source = ...; // Configure document source

FSProgressive *progressive = [fullTextSearch startUpdateIndex:source
                                                       pause:nil
                                                    reupdate:NO];

FSProgressiveState state = [progressive resume];
while (state == FSProgressiveToBeContinued) {
    state = [progressive resume];
}

if (state == FSProgressiveFinished) {
    NSLog(@"索引建立完成");
}

Step 3: Search

Implement FSSearchCallback:

@interface MySearchCallback : NSObject <FSSearchCallback>
@end

@implementation MySearchCallback

- (int)retrieveWithFile_path:(NSString *)filePath pageIndex:(int)pageIndex
                 matchResult:(NSString *)matchResult matchStartCharIndex:(int)matchStartCharIndex
             matchEndCharIndex:(int)matchEndCharIndex {
    NSLog(@"在文件 %@ 的第 %d 页找到: %@", filePath, pageIndex, matchResult);
    return 0; // 0 = continue; non-zero = stop
}

@end

Run search:

MySearchCallback *callback = [[MySearchCallback alloc] init];
BOOL result = [fullTextSearch searchOf:@"搜索关键词"
                             rank_mode:FSFullTextSearchRankModeNone
                              callback:callback];

Important

Indexing must run before search. The first index build can take time—run it on a background thread. After the database exists, searches are fast.

API reference

See the API reference for FSFullTextSearch and FSSearchCallback.