Objective-C Requires Chilkat v11.7.0+

Get a PDF Field Value by its Label (Value to the Right)

See more PDF Text Extraction Examples

Demonstrates the "label" option, which captures the text that belongs to a caption such as "Invoice Number:" without needing coordinates. With labelValue "right", the value is the rest of the label's line. Label matching ignores case, extra spaces and a trailing colon. 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 invoice 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;
}

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

//  The invoice has lines such as "Invoice Number:   INV-2026-0412".
//  The label option restricts the "text" operation to the text belonging to the label.
[json UpdateString: @"label" value: @"Invoice Number"];

//  "right" means the value is the rest of the label's line.
//  (The default, "auto", uses the rest of the line if there is text there, otherwise the block below.)
[json UpdateString: @"labelValue" value: @"right"];

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

//  The value is returned as the text.
NSLog(@"%@%@",@"Invoice Number: ",[jsonOut StringOf: @"text"]);

//  The labelMatches array tells where the label was found and how it appeared in the PDF.
NSLog(@"%@%d%@%@%@",@"Found on page ",[[jsonOut IntOf: @"labelMatches[0].page"] intValue],@" as \"",[jsonOut StringOf: @"labelMatches[0].label"],@"\"");

//  Matching ignores case and the trailing colon, so these all work:
[json UpdateString: @"label" value: @"CUSTOMER:"];
success = [pdf ExtractText: @"text" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%@",@"Customer: ",[jsonOut StringOf: @"text"]);

[json UpdateString: @"label" value: @"due date"];
success = [pdf ExtractText: @"text" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%@",@"Due Date: ",[jsonOut StringOf: @"text"]);

//  The totals at the foot of the invoice are right-aligned labels with the amount beside them.
[json UpdateString: @"label" value: @"Total Due"];
success = [pdf ExtractText: @"text" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@%@",@"Total Due: ",[jsonOut StringOf: @"text"]);

//  A label that is not found is not an error.  The text is empty, labelMatches is empty,
//  and the quality report has an issue with the code "labelNotFound".
[json UpdateString: @"label" value: @"Tracking Number"];
success = [pdf ExtractText: @"text" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

if ([[jsonOut SizeOfArray: @"labelMatches"] intValue] == 0) {
    NSLog(@"%@%@",@"Tracking Number: (not found) ",[jsonOut StringOf: @"quality.pages[0].issues[0].code"]);
}

//  Sample output:

//  Invoice Number: INV-2026-0412
//  Found on page 1 as "Invoice Number:"
//  Customer: Northwind Traders
//  Due Date: April 13, 2026
//  Total Due: $1,234.53
//  Tracking Number: (not found) labelNotFound