sharedbufferreceivedevent.yml

### YamlMime:TSType
name: SharedBufferReceivedEvent
uid: 'WebView2Script!SharedBufferReceivedEvent:class'
package: WebView2Script!
fullName: SharedBufferReceivedEvent
summary: >-
  Event object for the `chrome.webview.sharedbufferreceived` event. This event is dispatched when
  `CoreWebView2.PostSharedBufferToScript` is successfully called.
remarks: |-

  #### Examples

  The following example sends data to script for one-time, read-only consumption.

  First, in the native host app code, set data into the shared memory:

  ```cpp
  wil::com_ptr<ICoreWebView2ExperimentalEnvironment10> environment;
  CHECK_FAILURE(
      m_appWindow->GetWebViewEnvironment()->QueryInterface(IID_PPV_ARGS(&environment)));

  wil::com_ptr<ICoreWebView2ExperimentalSharedBuffer> sharedBuffer;
  CHECK_FAILURE(environment->CreateSharedBuffer(bufferSize, &sharedBuffer));
  // Add data to shared memory via IStream.
  wil::com_ptr<IStream> stream;
  CHECK_FAILURE(sharedBuffer->OpenStream(&stream));
  CHECK_FAILURE(stream->Write(data, sizeof(data), nullptr));
  PCWSTR additionalDataAsJson = L"{\"myBufferType\":\"bufferType1\"}";
  if (fromFrame)
  {
      m_webviewFrame4->PostSharedBufferToScript(
          sharedBuffer.get(), COREWEBVIEW2_SHARED_BUFFER_ACCESS_READ_ONLY,
          additionalDataAsJson);
  }
  else
  {
      m_webView18->PostSharedBufferToScript(
          sharedBuffer.get(), COREWEBVIEW2_SHARED_BUFFER_ACCESS_READ_ONLY,
          additionalDataAsJson);
  }
  // Close the one-time shared buffer, to release resources.
  sharedBuffer->Close();
  ```

  In the HTML document, subscribe to and handle sharedbufferreceived event.
  
  Next, in the HTML document, subscribe to and then handle the `sharedbufferreceived` event:

  ```html
  window.chrome.webview.addEventListener("sharedbufferreceived", e => {
      SharedBufferReceived(e);});
  ```

  ```html
  let readOnlySharedBuffer;
  function ShowReadOnlySharedBuffer() {
      if (readOnlySharedBuffer) {
          DisplaySharedBufferData(readOnlySharedBuffer);
      } else {
          // Post a web message to ask host to share the one time read only buffer.
          chrome.webview.postMessage("RequestOneTimeShareBuffer");
      }
  }

  function DisplaySharedBufferData(buffer) {
      document.getElementById("shared-buffer-data").value =
          new TextDecoder().decode(new Uint8Array(buffer));
  }

  function SharedBufferReceived(e) {
      if (e.additionalData && e.additionalData.myBufferType == "bufferType1") {
          readOnlySharedBuffer = e.getBuffer();
      } else {
          sharedBuffer = e.getBuffer();
      }
      DisplaySharedBufferData(e.getBuffer());
  }

  function ReleaseBuffer(buffer) {
      window.chrome.webview.releaseBuffer(buffer);
  }
  ```
isPreview: false
isDeprecated: false
type: class
properties:
  - name: additionalData
    uid: 'WebView2Script!SharedBufferReceivedEvent#additionalData:member'
    package: WebView2Script!
    fullName: additionalData
    summary: >-
      An object that is the result of parsing the `additionalDataAsJson` parameter to
      `CoreWebView2.PostSharedBufferToScript` as a JSON string. This property will be `undefined` if
      `additionalDataAsJson` is `nullptr` or the empty string.
    remarks: ''
    isPreview: false
    isDeprecated: false
    syntax:
      content: 'additionalData: any;'
      return:
        type: any
  - name: source
    uid: 'WebView2Script!SharedBufferReceivedEvent#source:member'
    package: WebView2Script!
    fullName: source
    summary: The source of the event is the `chrome.webview` object.
    remarks: ''
    isPreview: false
    isDeprecated: false
    syntax:
      content: 'source: WebView;'
      return:
        type: '<xref uid="WebView2Script!WebView:class" />'
methods:
  - name: getBuffer()
    uid: 'WebView2Script!SharedBufferReceivedEvent#getBuffer:member(1)'
    package: WebView2Script!
    fullName: getBuffer()
    summary: >-
      Returns an `ArrayBuffer` object with the backing content from the shared buffer passed to
      `CoreWebView2.PostSharedBufferToScript`<!-- -->. If `CoreWebView2.PostSharedBufferToScript` was called with the
      buffer set to `ReadOnly`<!-- -->, then only read access is allowed to the buffer. If you try to modify the content
      in a read-only buffer, it will cause an access violation in the WebView renderer process and crash the renderer
      process.
    remarks: ''
    isPreview: false
    isDeprecated: false
    syntax:
      content: 'getBuffer(): ArrayBuffer;'
      return:
        type: ArrayBuffer
        description: An `ArrayBuffer` over the shared buffer passed to `CoreWebView2.PostSharedBufferToScript`.
extends: <a href="https://developer.mozilla.org/docs/Web/API/Event">Event</a>