How can I use body-parser with LoopBack?

Just to be more clear about what it takes to get this working (because I still struggled for a while after finding this answer!), here are the steps I took:

As described above, in $APP_HOME/server/middleware.json, add the body-parser to the "parse" section:

{
  "initial:before": {
    "loopback#favicon": {}
  },
  "initial": {
    "compression": {},
    "cors": {
      "params": {
        "origin": true,
        "credentials": true,
        "maxAge": 86400
      }
    }
  },
  "session": {
  },
  "auth": {
  },
  "parse": {
    "body-parser#json": {},
    "body-parser#urlencoded": {"params": { "extended": true }}
  },
  "routes": {
  },
  "files": {
  },
  "final": {
    "loopback#urlNotFound": {}
  },
  "final:after": {
    "errorhandler": {}
  }
}

Next, I added the parser setup to $APP_HOME/server/server.js:

var loopback = require('loopback');
var bodyParser = require('body-parser');
var multer = require('multer');

var boot = require('loopback-boot');

var app = module.exports = loopback();

app.use(bodyParser.json()); // for parsing application/json
app.use(bodyParser.urlencoded({ extended: true })); // for parsing application/x-www-form-urlencoded
app.use(multer()); // for parsing multipart/form-data

app.start = function() {
...
...
cont'd

Then, since I didn't want to mess with custom routes, I added the following to $APP_HOME/common/models/model.js:

module.exports = function(Model) {

  Model.incoming = function(req, cb) {
    cb(null, 'Hey there, ' + req.body.sender);
  }
  Model.remoteMethod(
    'incoming',
    { accepts: [
      { arg: 'req', type: 'object', http: function(ctx) {
        return ctx.req;
      } 
    }],
    returns: {arg: 'summary', type: 'string'}
    }
  );
};

I can now run my app with $> slc run .

When I post to the endpoint, it now gets parsed properly, and all is well with the world. I hope this helps someone else!

Based on this answer https://stackoverflow.com/a/29813184/605586 from Ben Carlson you have to

npm install --save body-parser multer

then in your server.js require the modules:

var bodyParser = require('body-parser');
var multer = require('multer');

and use them before app.start:

app.use(bodyParser.json()); // for parsing application/json
app.use(bodyParser.urlencoded({ extended: true })); // for parsing application/x-www-form-urlencoded
app.use(multer().any()); // for parsing multipart/form-data

Then you can create a remote method:

App.incoming = function (req, cb) {
    console.log(req);
    // the files are available as req.files.
    // the body fields are available in req.body
    cb(null, 'Hey there, ' + req.body.sender);
}
App.remoteMethod(
    'incoming',
    {
    accepts: [
        {
        arg: 'req', type: 'object', http: function (ctx) {
            return ctx.req;
        }
        }],
    returns: { arg: 'summary', type: 'string' }
    }
);

Using this you can upload files and additional data fields to loopback with multipart/form-data.

I'm using loopback 2.14.0:

To make use of the body-parser in your custom bootscript routes you should only need to:

1) install body-parser npm install body-parser --save

2) Register the the module in middleware.json

"parse": {
"body-parser#json": {},
"body-parser#urlencoded": {"params": { "extended": true }}
},

There is no need to require the parser setup in server.js, loopback does this for you when you register the middleware.

Please note body parser is now installed in your source "node_modules" directory as well as in the loopback modules directory.

If at all possible try register custom remote methods as described in the loopback documentation.

Registering routes this way gives you access to loopback's body-parser out of the box and is the 'cleanest' implementation.

After hours of frustration, I just added it to middleware.json like so:

"parse": {
    "body-parser#json": {},
    "body-parser#urlencoded": {"params": { "extended": true }}
}

It is installed as a dependency. Now I have form data in req.body in my routes. My server/boot/routes.js looks like this:

module.exports = function(app) {
    app.post('/mailing_list', function(req, res) {
        console.log(req.body.email);
        res.send({"status": 1, "message": "Successfully added to mailing list."})
    });
}