Objective-C Requires Chilkat v11.7.0+
Objective-C
Extract Text from a PDF that Forbids Copying
See more PDF Text Extraction Examples
Demonstrates a PDF that opens without a password but whose permissions do not allow copying text. The "text", "markdown", "search" and "tables" operations fail with that reason; "assess" always works. Loading the PDF with the OwnerPassword property set grants owner rights, and extraction works.Chilkat Objective-C Downloads
#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 (owner password: owner-secret; copying not permitted) is available at no_copy_permission.pdf
CkoPdf *pdf = [[CkoPdf alloc] init];
CkoJsonObject *json = [[CkoJsonObject alloc] init];
CkoJsonObject *jsonOut = [[CkoJsonObject alloc] init];
// The PDF opens without a password.
success = [pdf LoadFile: @"qa_data/pdf/no_copy_permission.pdf"];
if (success == NO) {
NSLog(@"%@",pdf.LastErrorText);
return;
}
// Extracting text is refused, because the PDF's permissions do not allow copying.
success = [pdf ExtractText: @"text" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
NSLog(@"%@%@",@"Extraction refused: ",pdf.LastErrorText);
}
// "assess" reports only counts and ratings, never text, so it is always allowed.
success = [pdf ExtractText: @"assess" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
NSLog(@"%@",pdf.LastErrorText);
return;
}
NSLog(@"%@%@",@"rating: ",[jsonOut StringOf: @"quality.rating"]);
// Load with the owner password to get owner rights, which include copying.
pdf.OwnerPassword = @"owner-secret";
success = [pdf LoadFile: @"qa_data/pdf/no_copy_permission.pdf"];
if (success == NO) {
NSLog(@"%@",pdf.LastErrorText);
return;
}
success = [pdf ExtractText: @"text" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
NSLog(@"%@",pdf.LastErrorText);
return;
}
NSLog(@"%@",[jsonOut StringOf: @"text"]);
// Sample output:
// Extraction refused: ChilkatLog:
// ExtractText:
// ...
// The PDF's permissions do not allow copying or extracting text (load it with the owner password to extract).
// ...
// rating: good
// Visitor Leaflet
//
// Welcome to the harbor lighthouse. The tower is open on weekends from July to September.
//
// Please keep to the marked paths and do not climb on the breakwater.
//
// The lantern room is closed in high winds.