AsposePdfAddWatermark

Add watermark to a PDF-file.

function AsposePdfAddWatermark(
    fileBlob,
    fileName,
    text,
    fontName,
    fontSize,
    foregroundColor,
    xPosition,
    yPosition,
    rotation,
    isBackground,
    opacity,
    fileNameResult 
)

Parameters:

• fileBlob Blob object
• fileName file name
• text watermark text
• fontName font name
• fontSize font size
• foregroundColor text color (hexadecimal format “#RRGGBB”, where RR-red, GG-green and BB-blue hexadecimal integers)
• xPosition x watermark position
• yPosition y watermark position
• rotation watermark rotation (0-360)
• isBackground background (1 or 0)
• opacity opacity (decimal)
• fileNameResult result file name

Return:

JSON object

• errorCode - code error (0 no error)
• errorText - text error ("" no error)
• fileNameResult - result file name

Web Worker example:

  /*Create Web Worker*/
  const AsposePDFWebWorker = new Worker("AsposePDFforJS.js");
  AsposePDFWebWorker.onerror = evt => console.log(`Error from Web Worker: ${evt.message}`);
  AsposePDFWebWorker.onmessage = evt => document.getElementById('output').textContent = 
    (evt.data == 'ready') ? 'loaded!' :
      (evt.data.json.errorCode == 0) ? `Result:\n${DownloadFile(evt.data.json.fileNameResult, "application/pdf", evt.data.params[0])}` : `Error: ${evt.data.json.errorText}`;

  /*Event handler*/
  const ffileAddWatermark = e => {
    const file_reader = new FileReader();
    file_reader.onload = event => {
      const text = "Aspose PDF";
      const fontName = "Arial";
      const fontSize = 32;
      const foregroundColor = "#010101";
      const xPosition = 100;
      const yPosition = 100;
      const rotation = 45;
      const isBackground = 1;
      const opacity = 0.5;
      /*Add watermark to a PDF-file and save the "ResultPdfAddWatermark.pdf" - Ask Web Worker*/
      AsposePDFWebWorker.postMessage({ "operation": 'AsposePdfAddWatermark', "params": [event.target.result, e.target.files[0].name, text, fontName, fontSize, foregroundColor, xPosition, yPosition, rotation, isBackground, opacity, "ResultPdfAddWatermark.pdf"] }, [event.target.result]);
    };
    file_reader.readAsArrayBuffer(e.target.files[0]);
  };

  /*Make a link to download the result file*/
  const DownloadFile = (filename, mime, content) => {
      mime = mime || "application/octet-stream";
      var link = document.createElement("a"); 
      link.href = URL.createObjectURL(new Blob([content], {type: mime}));
      link.download = filename;
      link.innerHTML = "Click here to download the file " + filename;
      document.body.appendChild(link); 
      document.body.appendChild(document.createElement("br"));
      return filename;
    }

Simple example:

  var ffileAddWatermark = function (e) {
    const file_reader = new FileReader();
    file_reader.onload = (event) => {
      /*Add watermark to a PDF-file and save the "ResultPdfAddWatermark.pdf"*/
      const json = AsposePdfAddWatermark(event.target.result, e.target.files[0].name, "Aspose PDF", "Arial", 32, "#010101", 100, 100, 45, 1, 0.5, "ResultPdfAddWatermark.pdf");
      if (json.errorCode == 0) document.getElementById('output').textContent = json.fileNameResult;
      else document.getElementById('output').textContent = json.errorText;
      /*Make a link to download the result file*/
      DownloadFile(json.fileNameResult, "application/pdf");
    };
    file_reader.readAsArrayBuffer(e.target.files[0]);
  };