JavaScript Requires Chilkat v11.7.0+

Tile a Watermark Across a PDF Page

See more PDF Watermark Examples

Demonstrates a tiled watermark, which repeats the stamp over the whole page instead of placing it once. Tiling overrides position.align; tile.spacingX and spacingY set the gaps, and tile.stagger offsets alternate rows by half a tile so the pattern does not line up in columns. A faint tiled stamp carrying the name or address is the usual way to mark a document so that a leaked copy can be traced back, and zOrder back keeps it behind the text where it does not hinder reading. JavaScript

var success = false;

//  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 long_report.pdf

var pdf = new CkPdf();
success = pdf.LoadFile("qa_data/pdf/long_report.pdf");
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

var json = new CkJsonObject();
json.UpdateString("type","text");

//  {date:FORMAT} is replaced per page when the watermark is added.  The other placeholders are
//  {page}, {pages} and {filename}; {{ gives a literal brace.
json.UpdateString("text","jdoe@example.com  {date:yyyy-MM-dd}");
json.UpdateString("id","trace");
json.UpdateString("zOrder","back");
json.UpdateNumber("font.size","14");
json.UpdateNumber("opacity","0.15");
json.UpdateNumber("rotation","30");

json.UpdateBool("tile.enabled",true);
json.UpdateNumber("tile.spacingX","60");
json.UpdateNumber("tile.spacingY","80");
json.UpdateBool("tile.stagger",true);

var jsonOut = new CkJsonObject();
success = pdf.Watermark("add",json,jsonOut);
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

console.log("id: " + jsonOut.StringOf("id") + " pages: " + jsonOut.StringOf("pages"));

success = pdf.WriteFile("qa_output/report_traced.pdf");
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

//  Sample output:

//  id: trace pages: 1-3