$http.get messing JSON parameters - json

Question

I'm comunicating my Rails API with my AngularJS application.
Everything is working great and normal up until the point I have to send parameters in a GET request. This is the Rails controller
def cats
if cat_params[:color]
#cats = Cat.where(... #you know
else
//Do something else
end
private
def cat_params
params.require(:cat).permit(:color)
end
Then from Angular
var kitty = {
cat: {
color: "red"
}
}
$http.get('some URL', { params: kitty }).success.....
By this time, the params hash looks like a stringify JSON
Started GET "some URL?cat=%7B%22color%22:%22red%22%7D" for 127.0.0.1 at 2015-01-28 23:10:24 -0300
Processing by Some_controller as JSON
Parameters: {"cat"=>"{\"color\":\"red\"}", "cat_id"=>"19"}
Cat Load (0.5ms) SELECT "cat".* FROM "cats" WHERE "cat"."id" = 19 LIMIT 1
{"cat"=>"{\"color\":\"red\"}", "format"=>"json", "controller"=>"some_controller", "action"=>"some_action", "cat_id"=>"19"}
Completed 500 Internal Server Error in 95ms
NoMethodError - undefined method `permit' for "{\"cat\":\"red\"}":String:
I'm also sending the Content-Type header, set to 'application/json'.
From Angular's $http.get documentation, I read that if the value of params is something other than a string, it will stringify the JSON object, so the issue is not in the front-end.
I don't think the solution begins with starting JSON parsing the params hash, since I've had no need to do it in the past. It seems to me that strong_parameters is playing dirty, or Rails is ignoring the JSON string. Any ideas what to do next?

Answer 1

I just ran into the same issue. Changing the param serializer solved the issue for me:
$http.get('someURL', {
paramSerializer: '$httpParamSerializerJQLike',
params: {cat: {color: 'red}}
})
Also adding the 'Content-Type': 'application/json' header will not help since it applies to the the body the request.

Answer 2

I used to meet a $http.get problem that when call $http.get('some url', {params:SOME_PARAMS}), SOME_PARAMS could be transformd to key-value params when it is a simple key-value data like {color:'red'}, and it would transform params to json string when it is a complex type like {cat:{color:'red'}}.
So to solve your question, I suggest that add params behind url like:
$http.get('some URL?cat[color]=red').success.....