Call function in nodejs from angular application

Question

I'm having an angular app(angular-seed app) which should call a function in nodejs(web-server.js). The function in nodejs is just calls a batch file.

Answer 1

If I understood this correctly you want a click on the client-side (angular app) to call a batch file on the server side. You can do this in several ways depending on your requirements, but basically you want the client-side to send a http-request to the server (either with ajax call or form submit) and process this on the server that will call the batch file.

Client-side

On the client-side you need to have a button that uses the angular ng-click directive:

<button ng-click="batchfile()">Click me!</button>

In your angular controller you'll need to use the $http service to make a HTTP GET request to your server on some particular url. What that url is depends how you've set up your express app. Something like this:

function MyCtrl($scope, $http) { 
    // $http is injected by angular's IOC implementation

    // other functions and controller stuff is here...    

    // this is called when button is clicked
    $scope.batchfile = function() {
        $http.get('/performbatch').success(function() {
            // url was called successfully, do something 
            // maybe indicate in the UI that the batch file is
            // executed...
        });
    }

}

You can validate that this HTTP GET request is made by using e.g. your browser's developer tools such as Google Chrome's network tab or a http packet sniffer such as fiddler.

Server-side

EDIT: I incorrectly assumed that angular-seed was using expressjs, which it doesn't. See basti1302's answer on how to set it up server-side "vanilla style" node.js. If you're using express you can continue below.

On the server side you need to set up the url in your express app that will perform the batch file call. Since we let the client-side above make a simple HTTP GET request to /performbatch we'll set it up that way:

app.get('/performbatch', function(req, res){
    // is called when /performbatch is requested from any client

    // ... call the function that executes the batch file from your node app
});

Calling the batch file is done in some ways but you can read the stackoverflow answer here for a solution:

• node.js shell command execution

Hope this helps

Answer 2

The OP didn't mention express so I'll provide an alternative for the server side (Node.js part) without using any additional frameworks (which would require installing it via npm). This solution uses just node core:

web-server.js:

'use strict';

var http = require('http')
var spawn = require('child_process').spawn
var url = require('url')

function onRequest(request, response) {
  console.log('received request')
  var path = url.parse(request.url).pathname
  console.log('requested path: ' + path)
  if (path === '/performbatch') {
    // call your already existing function here or start the batch file like this:
    response.statusCode = 200
    response.write('Starting batch file...\n')
    spawn('whatever.bat')
    response.write('Batch file started.')
  } else {
    response.statusCode = 400
    response.write('Could not process your request, sorry.')
  }
  response.end()
}

http.createServer(onRequest).listen(8888)

Assuming you are on Windows, I would at first use a batch file like this to test it:

whatever.bat:

REM Append a timestamp to out.txt
time /t >> out.txt

For the client side, there is nothing to add to Spoike's solution.