> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/salesforce/content-edit/replacing-content-salesforce.md).

# Replace Document Text in Salesforce

Learn how to use ContentReplacer in WebViewer with this comprehensive guide. Find out how to replace content on a document and initialize PDFNet for redaction. Explore code samples and a live demo for

## Getting Started

We recommend familiarizing yourself with the [Overview](/salesforce/get-started/readme.md) page to learn how to correctly use a `config.js` file. If you are using a version of WebViewer older than `8.0+`, you should also learn about [`readerControl`](/salesforce/get-started/readme.md) before getting started. Make sure you also understand [document search](/salesforce/search/searching-documents-salesforce.md).

## WebViewer configuration required for ContentReplacer

In order to use the `ContentReplacer` class, you need to enable `fullAPI`. In your Lightning Web Component where you initialize WebViewer (you can check out [`pdftronWvInstance.js`](https://github.com/ApryseSDK/salesforce-pdf-app/blob/main/force-app/main/default/lwc/pdftronWvInstance/pdftronWvInstance.js) in our sample repository), include `fullAPI: true`:

<pre class="language-js" data-line-numbers><code class="lang-js">//snipped for brevity
const viewerElement = this.template.querySelector('div');

const viewer = new PDFTron.WebViewer({
    path: libUrl,
    custom: JSON.stringify(myObj),
    config: myfilesUrl + '/config_apex.js',
    fullAPI: true // this must be set to true
    // l: '<code class="expression">visitor.claims.wvKey || "YOUR_LICENSE_KEY"</code>_HERE',
}, viewerElement);
</code></pre>

Note: You need to use the `pdf_full.zip` file in your `/staticresources/` folder to access full API, which is required for redaction.

## Open a document

To replace content on a document, open it in WebViewer. Check out this [link](/salesforce/open-save/opening-documents-salesforce.md) to learn more.

## ContentReplacer placeholders

`ContentReplacer` is used for replacing strings that are wrapped in match strings. An example of this is `[Content to be replaced]`. This allows the user to build templates with these placeholders, which are then targeted by `ContentReplacer` and filled with data.

## Initializing PDFNet

`ContentReplacer` is a PDFNet class. Below is a code sample on how to initialize PDFNet:

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
const docViewer = instance.Core.documentViewer;
const doc = docViewer.getDocument();//get current document from WV
if (!doc) {
    return;
}
const PDFdoc = await doc.getPDFDoc(); //pass WV Doc to PDFNet
await PDFNet.initialize();

PDFdoc.initSecurityHandler();
PDFdoc.lock();

console.log('PDFNet initialized and document locked');
```

{% endcode %}
{% endtab %}
{% endtabs %}

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
const docViewer = readerControl.docViewer;
const doc = readerControl.docViewer.getDocument();//get current document from WV
if (!doc) {
    return;
}
const PDFdoc = await doc.getPDFDoc(); //pass WV Doc to PDFNet
await PDFNet.initialize();

PDFdoc.initSecurityHandler();
PDFdoc.lock();

console.log('PDFNet initialized and document locked');
```

{% endcode %}
{% endtab %}
{% endtabs %}

## Sample replaceContent() method

Place the following function into your `config.js` file:

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
async function replaceContent(searchString, replacementString) {
  const docViewer = instance.Core.documentViewer;
  const doc = docViewer.getDocument();//get current document from WV
  if (!doc) {
    return;
  }
  const PDFdoc = await doc.getPDFDoc(); //pass WV Doc to PDFNet
  await PDFNet.initialize();

  PDFdoc.initSecurityHandler();
  PDFdoc.lock();

  // Run PDFNet methods with memory management
  await PDFNet.runWithCleanup(async () => {
    // lock the document before a write operation
    // runWithCleanup will auto unlock when complete
    const replacer = await PDFNet.ContentReplacer.create();
    await replacer.setMatchStrings(searchString.charAt(0), searchString.slice(-1));
    await replacer.addString(searchString.slice(1, -1), replacementString);
    for (var i = 1; i <= docViewer.getPageCount(); ++i) {
      const page = await PDFdoc.getPage(i);
      await replacer.process(page);
    }
  });

  docViewer.refreshAll();
  docViewer.updateView();
  docViewer.getDocument().refreshTextData();
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
async function replaceContent(searchString, replacementString) {
  const docViewer = readerControl.docViewer;
  const doc = readerControl.docViewer.getDocument();//get current document from WV
  if (!doc) {
    return;
  }
  const PDFdoc = await doc.getPDFDoc(); //pass WV Doc to PDFNet
  await PDFNet.initialize();

  PDFdoc.initSecurityHandler();
  PDFdoc.lock();

  // Run PDFNet methods with memory management
  await PDFNet.runWithCleanup(async () => {
    // lock the document before a write operation
    // runWithCleanup will auto unlock when complete
    const replacer = await PDFNet.ContentReplacer.create();
    await replacer.setMatchStrings(searchString.charAt(0), searchString.slice(-1));
    await replacer.addString(searchString.slice(1, -1), replacementString);
    for (var i = 1; i <= docViewer.getPageCount(); ++i) {
      const page = await PDFdoc.getPage(i);
      await replacer.process(page);
    }
  });

  docViewer.refreshAll();
  docViewer.updateView();
  docViewer.getDocument().refreshTextData();
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

To handle posted messages to the WebViewer iFrame, use a `receiveMessage()` function like below:

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
//snipped for brevity
function receiveMessage(event) {
    if (event.isTrusted && typeof event.data === 'object') {
        switch (event.data.type) {
            case 'REPLACE_CONTENT':
                const { searchString, replacementString } = event.data.payload;
                replaceContent(searchString, replacementString);
                break;
            default:
                break;
    }
  }
}
```

{% endcode %}
{% endtab %}
{% endtabs %}

In your LWC component that hosts the WebViewer iFrame, you can communicate with the `config.js` file using `this.iframeWindow.postMessage({ type: 'REPLACE_CONTENT', payload }, '*');`.

Make sure that the payload you are publishing matches the structure of the `event.data.payload` object in your `receiveMessage()` function:

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
const payload = {
    searchString: this.searchTerm,
    replacementString: this.replaceTerm
}
fireEvent(this.pageRef, 'replace', payload); //fire pub-sub event or use LMS
```

{% endcode %}
{% endtab %}
{% endtabs %}

## Sample project

You can review the Salesforce PDF App to showcase an end-to-end example of search, and how you can leverage it for redaction and content replacing on our [Github repository](https://github.com/ApryseSDK/salesforce-pdf-app/).


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