How to best handle errors in ExpressJS POST routes - angularjs

Question

I am currently struggling with best practices for error handling in ExpressJS routes, particularly POST routes.
I have set up the default middleware error handling and I am using return next(err); in case of any errors. This works fine for all errors in GET routes.
However, what is the best practice to handle errors in the other route types, in particular POST routes?
On the front end, I am using AngularJS and I am posting using $http. When using return next(err); in the POST route, the .error(function(data,status,headers,config) of $http is called (AngularJS) and I receive the whole html error page inside data variable.
What I am looking for is a redirect for the user to the general error page through the ExpressJS middleware in case the client-side should not handle this error. This way, I could also do my error handling and logging at one single place.
So, my current idea: In POST routes, simply do return res.status(500).send({err: err}); In case the application cannot recover, then use a redirect on client side with AngularJS to a general error page. However, I would prefer to use the ExpressJS middleware to have a central place to handle errors.
I appreciate any help or pointers to best practice articles!
For reference, the (standard) error middleware function looks like this:
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('shared/error/error', {
message: err.message,
error: err
});
});

Answer 1

If you're using an angular $http method to GET or POST to your server, you should be returning JSON data back to the app to parse. For example, your route:
app.get('/example', function(req, res) {
getSomeData()
.then(function(data) {
res.status(200).json(data);
}, function(err) {
res.status(400).json(err);
});
});
In your angular service, you can create a method that returns the route's data in a promise:
angularApp.service('DataService', function($http) {
this.getData = function() {
return $http.get('/example')
};
});
Then use the service in your controller like this:
angularApp.controller('MyController', function($scope, DataService) {
DataService.getData()
.then(function(response) {
$scope.data = response.data;
}, function(err) {
showErrorMessage(err.statusText);
});
});