Objective-C Requires Chilkat v11.7.0+

Replace the Value After a Label in a PDF (Re-issue an Invoice)

See more PDF Text Replacement Examples

Demonstrates replacing the values that follow labels such as "Invoice Number:" on a PDF that has no placeholders -- an ordinary invoice. Each entry of the "labels" array names a label as it appears on the page and the new value; the value replaces the rest of the label's line. Label matching ignores case, extra spaces and a trailing colon. The replaced text is read back with ExtractText to confirm it. 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_labels.pdf

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

//  The invoice has lines such as "Invoice Number:   INV-2026-0412" and "Total Due:  $1,234.53".
//  Each label's new value replaces whatever follows the label on its line.
CkoJsonObject *json = [[CkoJsonObject alloc] init];
[json UpdateString: @"labels[0].label" value: @"Invoice Number:"];
[json UpdateString: @"labels[0].value" value: @"INV-2026-0500"];
[json UpdateString: @"labels[1].label" value: @"Invoice Date:"];
[json UpdateString: @"labels[1].value" value: @"April 2, 2026"];
[json UpdateString: @"labels[2].label" value: @"customer"];
[json UpdateString: @"labels[2].value" value: @"Contoso Ltd"];
[json UpdateString: @"labels[3].label" value: @"Total Due:"];
[json UpdateString: @"labels[3].value" value: @"$1,999.99"];

CkoJsonObject *jsonOut = [[CkoJsonObject alloc] init];
success = [pdf TextReplace: @"apply" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@%@",@"Not applied: ",[jsonOut Emit]);
    if (success == NO) {
        NSLog(@"%@",pdf.LastErrorText);
        return;
    }

}

int i = 0;
int count_i = [[jsonOut SizeOfArray: @"replacements"] intValue];
while (i < count_i) {
    jsonOut.I = [NSNumber numberWithInt: i];
    NSLog(@"%@%@%@%@",@"Replaced the value of \"",[jsonOut StringOf: @"replacements[i].label"],@"\" on page ",[jsonOut StringOf: @"replacements[i].pages"]);
    i = i + 1;
}

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

//  Read the new values back with ExtractText's label option.
CkoJsonObject *jsonRead = [[CkoJsonObject alloc] init];
CkoJsonObject *jsonText = [[CkoJsonObject alloc] init];
[jsonRead UpdateString: @"label" value: @"Total Due"];
[jsonRead UpdateString: @"labelValue" value: @"right"];
success = [pdf ExtractText: @"text" jsonIn: jsonRead jsonOut: jsonText];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%@",@"Total Due is now: ",[jsonText StringOf: @"text"]);

//  Sample output:

//  Replaced the value of "Invoice Number:" on page 1
//  Replaced the value of "Invoice Date:" on page 1
//  Replaced the value of "customer" on page 1
//  Replaced the value of "Total Due:" on page 1
//  Total Due is now: $1,999.99