How to perform Indexed Full-Text Search in Foxit PDF SDK for iOS?

Foxit PDF SDK for iOS fully supports Indexed Full Text Search. To use this feature, follow the steps below:

1) Get document source information. Create a document source based on a directory which will be used as the search directory.

-(id)initWithDirectory: (NSString *)directory;

2) Create a full text search object, and set a path of database to store the indexed data.

-(id)init;
-(void)setDataBasePath: (NSString *)path_of_data_base;

3) Start to index the PDF documents which receive from the source.

-(FSProgressive*)startUpdateIndex: (FSDocumentsSource*)source pause: (id)pause reUpdate: (BOOL)reUpdate;

Note: You can index a specified PDF file. For example, if the contents of a PDF file have been changed, you can re-index it using the following API:

-(BOOL)updateIndexWithFilePath: (NSString *)file_path;

4) Search the specified keyword from the indexed data source. The search results will be returned to external by a specified callback function when a matched one is found.

-(BOOL)searchOf: (NSString *)match_string rank_mode: (FSFullTextSearchRankMode)rank_mode callback: (id)Callback;

Following is a sample of how to use it:

- (void)FullTextSearch {
    
    NSString *directory = @"INPUT_DIRECTORY";
    FSDocumentsSource* docs = [[FSDocumentsSource alloc] initWithDirectory:directory];
    FSFullTextSearch* fulltextSearch = [FSFullTextSearch init];

NSString* dbPath = @"The path of data base to store the indexed data...";
[fulltextSearch setDataBasePath:dbPath];    

FSProgressive* progressive = [fulltextSearch startUpdateIndex:docs pause:nil reUpdate:NO];
    if (progressive) {
        while (true) {
            if ([progressive resume] != FSProgressiveToBeContinued) {
                break;
            }
        }
    }
    
    [fulltextSearch searchOf:@"Foxit" RankMode:FSFullTextSearchRankNone callback:[[FSSearchCallbackImp alloc] init]];
}

@end

A sample callback function is as follows:

@interface FSSearchCallbackImp: NSObject

@end

@implementation FSSearchCallbackImp

-(int)retrieveSearchResult: (NSString*)file_path page_index: (int)page_index match_result: (NSString*)match_result match_start_text_index: (int)match_start_text_index match_end_text_index: (int)match_end_text_index
{
    NSLog (@"file_path: %@\n", file_path);
    NSLog (@"page_index: %i， match_start_text_index: %i, match_end_text_index: %i\n", page_index, match_start_text_index, match_end_text_index);
    NSLog (@"match_result: %@\n\n", match_result);  return 0;  
} 

@end
</fssearchcallback>

• The indexed full text search provided by Foxit PDF SDK for Android will go through a directory recursively, so that both the files and the folders under the search directory will be indexed.
• If you want to abort the index process, you can pass in a pause callback parameter to the startUpdateIndex interface. The callback function needToPauseNow will be invoked once a PDF document is indexed, so that the caller can abort the index process when the callback needToPauseNow return “true”.
• The location of the indexed database is set by setDataBasePath interface. If you want to clear the indexed database, you shoud do it manually. And now, removing a file from index function is not supported.
• Every search result of the searchOf interface is returned to external by a specified callback. Once the searchOf interface returns “true” or “false”, it means the searching is finished.