webextension native application c++ hello world

Question

I want to create a webextension on firefox, that communicate with a simple c++ application, I would like to send a message to the c++ application, and to recieve a simple message(Hello world by example).

For now this is what I have done :

manifest.json (webextension)

{
  "manifest_version": 2,
  "name": "nameofwebextension",
  "version": "1.0",

  "description": "test",
    "permissions": [
    "tabs",
    "activeTab",
    "downloads",
    "downloads.open",
    "nativeMessaging"
    ],
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
  {
    "matches": ["http://www.testwebsite.com/*"],
    "js": ["content.js"]
  }
    ],
  "background": {
  "scripts": ["background.js"]
},
  "browser_action": {
    "default_icon": "icons/beasts-32.png",
    "default_title": "test",
    "default_popup": "popup/test.html",
    "browser_style": false
  },

    "applications": {
    "gecko": {
      "id": "name@example.org",
      "strict_min_version": "50.0"
    }
  }

}

background.js

var port = browser.runtime.connectNative("nameofapp");
console.log("Sending:  ping");
port.postMessage("ping");
port.onMessage.addListener((response) => {
  console.log("Received: " + response);
});

manifest.json (c++ app)

{
  "name": "nameofapp",
  "description": "Example host for native messaging",
  "path": "bin/Debug/nameofapp.exe",
  "type": "stdio",
  "allowed_extensions": [ "name@example.org" ]
}

main.cpp

#include <iostream>

using namespace std;

int main()
{
    cout << "Hello world!" << endl;
    //cin.get();
    return 0;
}

i have also create the right key in the registry editor.

This what I get into the browser console :

Sending:  ping  
Native application tried to send a message of 1819043144 bytes, 
which exceeds the limit of 1048576 bytes.

score 1 · Accepted Answer · answered Feb 23 '17 at 15:49

I found the answer here : https://groups.google.com/a/chromium.org/forum/#!msg/chromium-extensions/Y5RckbPVnr8/xe5w9RC6O5sJ

#include <iostream>

int main(int argc, char* argv[])
{
    std::cout.setf( std::ios_base::unitbuf ); //instead of "<< eof" and "flushall"
    unsigned int a, c, i, t=0;
    std::string inp;
    bool bCommunicationEnds = false;

    do {

        inp="";
        t=0;
        // Sum the first 4 chars from stdin (the length of the message passed).
        for (i = 0; i <= 3; i++)
        {
//          t += getchar();
            t += std::cin.get();
        }
        // Loop getchar to pull in the message until we reach the total
        //  length provided.
        for (i=0; i < t; i++)
        {
            //c = getchar();
            c = std::cin.get();
            //if(c == EOF)
            if(c == 65)
            {
                bCommunicationEnds = true;
                i = t;
            }
            else
            {
                inp += c;
            }
        }

        if(!bCommunicationEnds)
        {
            //Collect the length of the message
             unsigned int len = inp.length();
            //unsigned int len = strJson.length();
            //// We need to send the 4 btyes of length information
            std::cout << char(((len>>0) & 0xFF))
                << char(((len>>8) & 0xFF))
                << char(((len>>16) & 0xFF))
                << char(((len>>24) & 0xFF));
            //// Now we can output our message
            std::cout << inp;

        }
    }while(!bCommunicationEnds);
    return 0;
}

webextension native application c++ hello world

1 Answers1