Chrome extension Native messaging synchronization

问题

I have problem with Native messaging synchronization on windows. I am trying to synchronize the message between backgroundPage and hostApp. normally, we use native messaging like this:

//popup.js
function appendMessage(text) {
  document.getElementById('response').innerHTML += "<p>" + text + "</p>";
}

function sendNativeMessage() {
  message = {"command": document.getElementById('input-text').value};
  port.postMessage(message);
  appendMessage("Sent message: <b>" + JSON.stringify(message) + "</b>");
}
function onNativeMessage(message) {
  appendMessage("Received message: <b>" + JSON.stringify(message) + "</b>");
}

function onDisconnected() {
  appendMessage("Failed to connect: " + chrome.runtime.lastError.message);
  port = null;
  updateUiState();
}

function connect() {
  var hostName = "com.google.chrome.example.dmtest1";
  appendMessage("Connecting to native messaging host <b>" + hostName + "</b>");
  port = chrome.runtime.connectNative(hostName);
  port.onMessage.addListener(onNativeMessage);
  port.onDisconnect.addListener(onDisconnected);
  updateUiState();
}

document.addEventListener('DOMContentLoaded', function () {
  document.getElementById('connect-button').addEventListener(
      'click', connect);
  document.getElementById('send-message-button').addEventListener(
      'click', sendNativeMessage);
  updateUiState();
});


<html>
  <head>
    <script src='./popup.js'></script>
  </head>
  <body>
    <button id='connect-button'>Connect</button>
    <input id='input-text' type='text' />
    <button id='send-message-button'>Send</button>
    <div id='response'></div>
  </body>
</html>

but the sendNativeMessage() and onNativeMessage(..) functions are asynchronous, and I want to make them synchronous. I tried the method below but it failed to get the response data from the host(c++ exe), and it made chrome crash.

function sendNativeMessage() {
  var message = {"command": document.getElementById('input-text').value};
  port.postMessage(message);
  appendMessage("Sent message: <b>" + JSON.stringify(message) + "</b>");

  port.onMessage.addListener(function(msg) { 
    appendMessage("Receive message: <b>" + JSON.stringify(msg) + "</b>");
  });
}

How can I do this, is it possible, Any help?

回答1:

After several days of search and test, I finally found an answer(here: how to handle chrome.runtime.sendNativeMessage() in native app) and solved my problem. I give up the idea about making my callback functions synchronous, I just use another way of communicating between Chrome extension backpage and my local host app. Instead of var port = chrome.runtime.connectNative(hostName);port.onMessage.addListener(onNativeMessage);port.postMessage(message); I used the code below to send and receive data between backpage and hostapp, and it is synchronous:

chrome.runtime.sendNativeMessage(hostName, sendMsg, function(response) {
            if (chrome.runtime.lastError) {
                alert("ERROR: " + chrome.runtime.lastError.message);
            } else {
                sendResponse({farewell: ParseJSON(response)});
            }
        });

来源：https://stackoverflow.com/questions/31201420/chrome-extension-native-messaging-synchronization

标签

javascript

google-chrome-extension

chrome-native-messaging