AsposePdfAddBackgroundImage

Add background image to PDF file.

function AsposePdfAddBackgroundImage(
    fileBlob,
    fileName,
    fileBackgroundImage,
    fileResultName
)

Parameters:

• fileBlob Blob object
• fileName file name
• fileBackgroundImage image file name
• fileResultName result file name

Return:

JSON object

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

Example:

  /*set the default image filename*/
  var fileBackgroundImage = "/Aspose.jpg";

  var ffileImage = function (e) {
    const file_reader = new FileReader();
    /*set the image filename*/
    fileBackgroundImage = e.target.files[0].name;
    file_reader.onload = (event) => {
      /*prepare(save) the image file from BLOB*/
      AsposePdfPrepare(event.target.result, fileBackgroundImage);
    };
    file_reader.readAsArrayBuffer(e.target.files[0]);
  };

  var ffileAddBackgroundImage = function (e) {
    const file_reader = new FileReader();
    file_reader.onload = (event) => {
      /*add a background image file a PDF-file and save the "ResultBackgroundImage.pdf"*/
      const json = AsposePdfAddBackgroundImage(event.target.result, e.target.files[0].name, fileBackgroundImage, "ResultBackgroundImage.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]);
  };

Web Worker:

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

  /*set the default image filename: 'Aspose.jpg' already loaded, see settings in 'settings.json'*/
  var fileBackgroundImage = "Aspose.jpg";

  /*Event handler*/
  const ffileAddBackgroundImage = e => {
    const file_reader = new FileReader();
    file_reader.onload = event => {
      /*add a background image file a PDF-file and save the "ResultBackgroundImage.pdf" - Ask Web Worker*/
      AsposePDFWebWorker.postMessage(
        { "operation": 'AsposePdfAddBackgroundImage',
          "params": [event.target.result, e.target.files[0].name, fileBackgroundImage, "ResultBackgroundImage.pdf"] },
        [event.target.result]
      );
    };
    file_reader.readAsArrayBuffer(e.target.files[0]);
  };

  const ffileImage = e => {
    const file_reader = new FileReader();
    /*set the image filename*/
    fileBackgroundImage = e.target.files[0].name;
    file_reader.onload = event => {
      /*prepare(save) the image file from BLOB*/
      AsposePDFWebWorker.postMessage(
        { "operation": 'AsposePdfPrepare', "params": [event.target.result, e.target.files[0].name] },
        [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;
    }