chrome.runtime.connectNative generates Uncaught TypeError: undefined is not a function

Question

I did write an chrome extension that calls this connect() function to connect to a local C++ program: ``` function connect() { console.log("test1"); //port = chrome.extension.connectNative('com.a.chrome_interface'); port = chrome.runtime.connectNative('com.a.chrome_interface'); port.onMessage.addListener(onNativeMessage); port.onDisconnect.addListener(onDisconnected); console.log("test5"); } ``` I can see the test1 in the Console, but afterwards I got the error ``` Uncaught TypeError: undefined is not a function ``` in the line ``` port = chrome.runtime.connectNative('com.a.chrome_interface'); ``` My extensions manifest file is here: ``` { "name": "CPP_Connect", "version": "1.0", "description": "Send data to CPP program", "content_scripts": [ { "matches": [""], "js": ["contentscript.js"] } ], "permissions": ["contextMenus", "tabs", "nativeMessaging", ""], "manifest_version": 2 } ``` My com.a.chrome_interface.json looks like this: ``` { "name": "com.a.chrome_interfa…

Accepted Answer

`connectNative()` is not available in a content scripts. To connect to a local program the content script must send the data e.g. to the background script of the extension and in the background script, `port = chrome.extension.connectNative` can be used. So here a solution:

contentscript.js:

```
....
// send data to background script
chrome.extension.sendRequest("Some Data");
....
```

background.js:

```
function connect() {
    // connect to local program com.a.chrome_interface
    port = chrome.extension.connectNative('com.a.chrome_interface');
    port.onMessage.addListener(onNativeMessage);
    port.onDisconnect.addListener(onDisconnected);
}

chrome.extension.onRequest.addListener(function(data, sender) {
    if (data.length > 0) {
        connect();
        sendNativeMessage(data);
    }
});
```

manifest.json as above in my question but additionaly:

```
...
  "background": {
  "scripts": ["background.js"]
  },
...
```

`com.a.chrome_interface.json` is unchange as in the question above.

chrome.runtime.connectNative generates Uncaught TypeError: undefined is not a function

Solution

Problem