strong parameter and json input rails 4

Question

I am trying to save data through JSON String in which I have nested associated attributes. I do not want to use attr_accessible. I almost got the logic of strong parameter but still got the problem to make them work. I am getting JSON string and using it to save data using this ``` data = request.body.read @inputData = Person.new(JSON.parse(data)) @inputData.save! if@inputData.valid? render :status => 200, :json => "Data inserted successfully" else render :status => 404, :json => "Not Inserted " end ``` I have defined permit strong parameter method allow nested attributes like this ``` def referral_params params.require(:person).permit(:id, user_attributes: [:id, :first_name, :last_name, :email], device_attributes: [:id, :os_type, :os_version], location_attributes: [:id, :latitude, :longitude], duration_attributes[:id, :start_time, :end_time]) end ``` But I am not sure how to use this regerral_params method along with JSON input string....

Accepted Answer

You could try changing your `referral_params` method to this:

```
def referral_params
  json_params = ActionController::Parameters.new( JSON.parse(request.body.read) )
  return json_params.require(:person).permit(:id, user_attributes: [:id, :first_name, :last_name, :email], device_attributes: [:id, :os_type, :os_version], location_attributes: [:id, :latitude, :longitude], duration_attributes[:id, :start_time, :end_time])
end
```

The first line inside the method parses your JSON (which returns a Ruby hash, if I remember correctly) and creates a new `ActionController::Parameters` object from that. The second one uses `permit` and `require` on that params-like object.

`params` is usually automatically created from post data key/value pairs, and will be of the type `ActionController::Parameters`. To use `permit` and `require`, you have to create an object of that class manually from a hash.

To then use these sanitized params, you have to change

```
@inputData = Person.new(JSON.parse(data))
```

to

```
@inputData = Person.new(referral_params)
```

strong parameter and json input rails 4

Solution

Problem