Objective-C Requires Chilkat v11.7.0+

Search for Text in a PDF

See more PDF Text Extraction Examples

Demonstrates the "search" operation, which finds every occurrence of a string in a PDF and returns each match with its page number and the text around it. Matching ignores case unless caseSensitive is true. Objective-C

#import <CkoPdf.h>
#import <CkoJsonObject.h>

BOOL success = NO;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The three-page PDF used in this example is available at search_context.pdf

CkoPdf *pdf = [[CkoPdf alloc] init];
success = [pdf LoadFile: @"qa_data/pdf/search_context.pdf"];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

CkoJsonObject *json = [[CkoJsonObject alloc] init];
CkoJsonObject *jsonOut = [[CkoJsonObject alloc] init];

//  The string to find.
[json UpdateString: @"query" value: @"chilkat"];

//  The number of characters returned before and after each match.  The default is 40.
[json UpdateInt: @"context" value: [NSNumber numberWithInt: 30]];

success = [pdf ExtractText: @"search" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

//  "count" is the number of matches.  Each match has the page, the matched text as it appears
//  in the PDF, and the text before and after it.
NSLog(@"%@%d",@"Matches: ",[[jsonOut IntOf: @"count"] intValue]);

int i = 0;
int count_i = [[jsonOut SizeOfArray: @"matches"] intValue];
while (i < count_i) {
    jsonOut.I = [NSNumber numberWithInt: i];
    NSLog(@"%@%d%@%@%@%@%@%@%@",@"page ",[[jsonOut IntOf: @"matches[i].page"] intValue],@": ...",[jsonOut StringOf: @"matches[i].before"],@"[",[jsonOut StringOf: @"matches[i].text"]
        ,@"]",[jsonOut StringOf: @"matches[i].after"],@"...");
    i = i + 1;
}

//  The search ignores case by default.  Set caseSensitive to find only the exact spelling.
[json UpdateBool: @"caseSensitive" value: YES];
[json UpdateString: @"query" value: @"Chilkat"];
success = [pdf ExtractText: @"search" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%d",@"Case-sensitive matches for Chilkat: ",[[jsonOut IntOf: @"count"] intValue]);

//  Sample output:

//  Matches: 5
//  page 1: ...[Chilkat] River Field Notes The Chilkat...
//  page 1: ...Chilkat River Field Notes The [Chilkat] River runs for about fifty mi...
//  page 2: ...DAY ONE: UPPER [CHILKAT] FLATS Clear and cold, minus e...
//  page 2: ...he river is sometimes spelled [chilkat] in older records, and the val...
//  page 3: ...y because the fish run on the [Chilkat] was thinning. Two tagged bird...
//  Case-sensitive matches for Chilkat: 3