AngularJS sends nil parameters to API - ruby-on-rails

Question

I created a basic API with Ruby on Rails. Whenever I try to send data from a form in AngularJS, I get this message in the Rails Server:
Parameters: {"{\"content\":\"message\"}"=>nil}
So, it's creating null records in the DB.
This is the controller in AngularJS to send the data:
app.controller('postController', function($scope, $http) {
// create a blank object to handle form data.
$scope.message = {};
// calling submit function.
$scope.submitForm = function() {
$http({
method : 'POST',
url : 'http://localhost:3000/api/v1/messages',
data : $scope.message, //forms user object
headers : {'Content-Type': 'application/x-www-form-urlencoded'}
})
.success(function(data) { ... }
});
};
});

Answer 1

You need to serialize the data when you send as x-www-form-urlencoded
Example copied from docs
.controller(function($http, $httpParamSerializerJQLike) {
//...
$http({
url: myUrl,
method: 'POST',
data: $httpParamSerializerJQLike(myData),
headers: {
'Content-Type': 'application/x-www-form-urlencoded'
}
});
});
Or use the defaults of $http which sends JSON in request body as application/json:
$http.post(myurl, data).then(...;

Answer 2

change this line:
headers : {'Content-Type': 'application/x-www-form-urlencoded'}
to:
headers : {'Content-Type': 'application/json'}
Also encode to Json if it isnt like this:
data : angular.toJson($scope.message), //forms user object
This way you will send the correct JSON formatted data to API, make sure your API accepts Json encoded data just in case.