Use zmq to send settings.

app/app.js

@@ -1 +1,55 @@
-console.log("cool")
+'use strict'
+
+function attachDOMListeners(){
+  document.getElementById('run_langform').addEventListener('click', () => {
+    //langform_start
+
+    var child = require('child_process').execFile;
+
+    // TODO: (re)start langform here, or ensure it's running in the background
+
+    var executablePath = "/home/walid/Documents/python_shell_simple_com/zmq_client";
+
+    // Use a real directory
+    var classXMLDirValue = "'/home/walid/shared_on_wifi/xml/'"
+    // Use null to be translated to None by the json parser
+    // Follow https://docs.python.org/2/library/json.html#encoders-and-decoders
+    classXMLDirValue = "null"
+
+    var classXMLDir = '\"classXMLDir\":' + classXMLDirValue +''
+
+    var settings =  "\"settings\": {"
+    settings += classXMLDir
+    settings += "}"
+
+    var msg = "{" + settings + "}"
+
+    var localhost = "127.0.0.1"
+    var port = "3000"
+
+    var parameters = ["--msg="+msg, "--localhost="+localhost, "--port="+port];
+
+
+    console.log("Set to send: "+ msg +" over "+ localhost +":"+ port +".");
+
+    var fs = require('fs');
+    if (fs.existsSync(executablePath)) {
+      child(executablePath, parameters, function(err, data) {
+        console.log("Sending settings and executing.");
+        if(err){
+          console.error(err);
+          return;
+        }
+        console.log(data.toString());
+      });
+    }
+    else {
+      console.error(executablePath + " couldn't be found.")
+    }
+  });
+};
+
+document.addEventListener('DOMContentLoaded', function () {
+  // get elements only when the DOM is loaded
+  attachDOMListeners();
+});