Edit PDF Elements - Sample Code

Requirements

These packages are required to use these features in production. Trial keys have unlimited access to all features

Web SDKFull API

Sample JavaScript code for using Apryse SDK to programmatically edit an existing PDF document's page display list and the graphics state attributes on existing elements.

In particular, this sample strips all images from the page and changes the text color to blue. Some of Apryse SDK's other functions for programmatically editing PDFs include the Cos/SDF low-level API, page manipulation, and more.

Learn more about our Web SDK and PDF Editing & Manipulation Library.

Implementation steps

Step 1: Follow get started in your preferred web stack for WebViewer Step 2: Enable the full API by passing the fullAPI option into the WebViewer constructor Step 3: Add the sample code provided in this guide

This full sample is one of many included in the manual download of WebViewer.

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2023 by Apryse Software Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

(exports => {

  exports.runElementEditTest = () => {
    const PDFNet = exports.Core.PDFNet;

    async function ProcessElements(reader, writer, visited) {
      await PDFNet.startDeallocateStack();
      const colorspace = await PDFNet.ColorSpace.createDeviceRGB();
      const redColor = await PDFNet.ColorPt.init(1, 0, 0, 0);
      const blueColor = await PDFNet.ColorPt.init(0, 0, 1, 0);

      for (let element = await reader.next(); element !== null; element = await reader.next()) {
        const elementType = await element.getType();
        let gs;
        let formObj;
        let formObjNum = null;
        switch (elementType) {
          case PDFNet.Element.Type.e_image:
          case PDFNet.Element.Type.e_inline_image:
            // remove all images by skipping them
            break;
          case PDFNet.Element.Type.e_path:
            // Set all paths to red
            gs = await element.getGState();
            gs.setFillColorSpace(colorspace);
            gs.setFillColorWithColorPt(redColor);
            writer.writeElement(element);
            break;
          case PDFNet.Element.Type.e_text:
            // Set all text to blue
            gs = await element.getGState();
            gs.setFillColorSpace(colorspace);
            gs.setFillColorWithColorPt(blueColor);
            writer.writeElement(element);
            break;
          case PDFNet.Element.Type.e_form:
            writer.writeElement(element);
            formObj = await element.getXObject();
            formObjNum = formObj.getObjNum();
            // if XObject not yet processed
            if (visited.indexOf(formObjNum) === -1) {
              // Set Replacement
              const insertedObj = await formObj.getObjNum();
              if (!visited.includes(insertedObj)) {
                visited.push(insertedObj);
              }
              const newWriter = await PDFNet.ElementWriter.create();
              reader.formBegin();
              newWriter.beginOnObj(formObj, true);
              await ProcessElements(reader, newWriter, visited);
              newWriter.end();
              reader.end();
            }
            break;
          default:
            writer.writeElement(element);
        }
      }
      await PDFNet.endDeallocateStack();
    }

    const main = async () => {
      console.log('Beginning Test');
      const ret = 0;
      // Relative path to the folder containing test files.
      const inputUrl = '../TestFiles/';
      const doc = await PDFNet.PDFDoc.createFromURL(inputUrl + 'newsletter.pdf');
      doc.initSecurityHandler();
      doc.lock();

      console.log('PDF document initialized and locked');
      const writer = await PDFNet.ElementWriter.create();
      const reader = await PDFNet.ElementReader.create();
      const visited = [];

      const totalPageNumber = await doc.getPageCount();

      const itr = await doc.getPageIterator(1);

      // Read every page
      for (itr; await itr.hasNext(); itr.next()) {
        const page = await itr.current();
        const currentPageNumber = await page.getIndex();
        console.log('Processing elements on page ' + currentPageNumber + '/' + totalPageNumber);
        const sdfObj = await page.getSDFObj();
        // Set Replacement
        const insertedObj = await sdfObj.getObjNum();
        if (!visited.includes(insertedObj)) {
          visited.push(insertedObj);
        }
        reader.beginOnPage(page);
        writer.beginOnPage(page, PDFNet.ElementWriter.WriteMode.e_replacement, false);
        await ProcessElements(reader, writer, visited);
        writer.end();
        reader.end();
      }

      const docBuffer = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_remove_unused);
      saveBufferAsPDFDoc(docBuffer, 'newsletter_edited.pdf');
      console.log('Done.');
      return ret;
    };

    // add your own license key as the second parameter, e.g. PDFNet.runWithCleanup(main, 'YOUR_LICENSE_KEY')
    PDFNet.runWithCleanup(main);
  };
})(window);
// eslint-disable-next-line spaced-comment
//# sourceURL=ElementEditTest.js