Objective-C Requires Chilkat v11.7.0+

Replace the Second (or Every) Occurrence of a Label in a PDF

See more PDF Text Replacement Examples

Demonstrates the "occurrence" member of a label entry. By default the first occurrence of a label, in reading order across the selected pages, is replaced; "occurrence" can be a number for the nth, or "all" for every occurrence. The invoice template has "Ref:" twice. 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 PDF used in this example is available at invoice_template.pdf

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

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

//  This template's {{placeholders}} are not being filled here: "keep" leaves them as they are
//  (the default, "error", would refuse to apply while a placeholder on the page has no value).
[json UpdateString: @"unusedPlaceholders" value: @"keep"];

//  "Ref:" appears twice on the page (A-1 near the top, A-2 below the totals).
//  The default replaces the first occurrence only.
[json UpdateString: @"labels[0].label" value: @"Ref:"];
[json UpdateString: @"labels[0].value" value: @"B-7"];
success = [pdf TextReplace: @"check" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%d%@",@"default: ",[[jsonOut IntOf: @"replacements[0].count"] intValue],@" occurrence replaced");

//  The second occurrence only.
[json UpdateString: @"labels[0].occurrence" value: @"2"];
success = [pdf TextReplace: @"check" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%d%@",@"occurrence 2: ",[[jsonOut IntOf: @"replacements[0].count"] intValue],@" occurrence replaced");

//  Every occurrence.
[json UpdateString: @"labels[0].occurrence" value: @"all"];
success = [pdf TextReplace: @"apply" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%d%@",@"occurrence all: ",[[jsonOut IntOf: @"replacements[0].count"] intValue],@" occurrences replaced");

success = [pdf WriteFile: @"qa_output/invoice_refs.pdf"];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

//  Sample output:

//  default: 1 occurrence replaced
//  occurrence 2: 1 occurrence replaced
//  occurrence all: 2 occurrences replaced