Objective-C Requires Chilkat v11.7.0+

Fill a PDF Template: Replace {{placeholders}} with Values

See more PDF Text Replacement Examples

Demonstrates the TextReplace method on an invoice template whose values are written as placeholders such as {{customer}} and {{total}}. The "placeholders" object names each placeholder and the text to put in; every occurrence on the page is replaced, including a placeholder inside a sentence or inside a label such as "Tax ({{taxRate}}):". The text is redrawn with the font the template used, so the result looks like the template, and a value that is right-aligned in the template stays right-aligned. The changes are written by WriteFile. 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;
}

//  The template has these placeholders in its page text:
//    {{customer}} (twice: "Bill To:" and the closing sentence), {{date}}, {{po}},
//    two item rows: {{qty1}} {{desc1}} {{price1}} {{amount1}} and {{qty2}} {{desc2}} {{price2}} {{amount2}},
//    {{subtotal}}, "Tax ({{taxRate}}):" with {{tax}}, and {{total}}.
CkoJsonObject *json = [[CkoJsonObject alloc] init];
[json UpdateString: @"placeholders.customer" value: @"Acme Corp"];
[json UpdateString: @"placeholders.date" value: @"2026-10-18"];
[json UpdateString: @"placeholders.po" value: @"PO-88213"];
[json UpdateString: @"placeholders.qty1" value: @"2"];
[json UpdateString: @"placeholders.desc1" value: @"Cordless drill, 18 V"];
[json UpdateString: @"placeholders.price1" value: @"$460.00"];
[json UpdateString: @"placeholders.amount1" value: @"$920.00"];
[json UpdateString: @"placeholders.qty2" value: @"6"];
[json UpdateString: @"placeholders.desc2" value: @"Galvanized hinge, 4 inch"];
[json UpdateString: @"placeholders.price2" value: @"$12.50"];
[json UpdateString: @"placeholders.amount2" value: @"$75.00"];
[json UpdateString: @"placeholders.subtotal" value: @"$995.00"];
[json UpdateString: @"placeholders.taxRate" value: @"7.35%"];
[json UpdateString: @"placeholders.tax" value: @"$73.13"];
[json UpdateString: @"placeholders.total" value: @"$1,068.13"];

//  "apply" makes every replacement, or none: if any value cannot be drawn with the
//  template's font, the method returns false, the PDF is unchanged, and jsonOut says why.
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;
    }

}

//  One entry per placeholder: the pages it was found on and how many times it was replaced.
int i = 0;
int count_i = [[jsonOut SizeOfArray: @"replacements"] intValue];
while (i < count_i) {
    jsonOut.I = [NSNumber numberWithInt: i];
    NSLog(@"%@%@%d%@%@",[jsonOut StringOf: @"replacements[i].field"],@": ",[[jsonOut IntOf: @"replacements[i].count"] intValue],@" on page(s) ",[jsonOut StringOf: @"replacements[i].pages"]);
    i = i + 1;
}

//  The replacements stay in memory until the PDF is written.
success = [pdf WriteFile: @"qa_output/invoice_filled.pdf"];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@",@"Wrote qa_output/invoice_filled.pdf");

//  Sample output:

//  customer: 2 on page(s) 1
//  date: 1 on page(s) 1
//  po: 1 on page(s) 1
//  qty1: 1 on page(s) 1
//  desc1: 1 on page(s) 1
//  price1: 1 on page(s) 1
//  amount1: 1 on page(s) 1
//  qty2: 1 on page(s) 1
//  desc2: 1 on page(s) 1
//  price2: 1 on page(s) 1
//  amount2: 1 on page(s) 1
//  subtotal: 1 on page(s) 1
//  taxRate: 1 on page(s) 1
//  tax: 1 on page(s) 1
//  total: 1 on page(s) 1
//  Wrote qa_output/invoice_filled.pdf