Ruby API 响应视图：如何呈现 JSON 响应？

Question

I'm new to Ruby, trying to building an API.

I've followed a tutorial and was able to return a JSON response when calling an API endpoint.

In this example, the function called raises an error that I want to pass as a JSON response.

my_controller.rb

class MyController < ApplicationController
  def getTracklist

    begin
      importer = #this raises an error
    rescue StandardError => e
      @response = {
      error:  e.message,
      }
      return @response
    end

  end

end

my view look like this :

getTracklist.json.jbuilder

json.response @response

thing is,

this works but renders my response as

{"response":{"error":"the error message"}}

while I want it as

{"error":"the error message"}

I made an attempts by changing my view to

json @response

but it fails :

ActionView::Template::Error (undefined method `json' for <#:0x0000559304675470> Did you mean? JSON): 1: json @response

So how could I render my response "fully" without having to put it in a property ?

I've also seen when reading stuff about ROR that this code is sometimes used, and I was wondering how I could use it in this situation :

render json: { error_code:'not_found', error: e.message }, status: :not_found

Thanks !

Answer 1

There are multiple ways of achieving what you want. You could merge! the response into the jbuilder root.

json.merge! @response

The above merges all key/value-pairs into the jbuilder root. You could also opt to extract! specific attributes.

json.extract! @response, :error

Alternatively you can simply render it in the controller, since you've already composed the structure the following would be enough.

render json: @response

Answer 2

You can do this for jBuilder:

json.merge!(@response)

Source

Answer 3

class MyController < ApplicationController
  def getTracklist

    begin
     # you need to assign something to a variable
    rescue StandardError => e
      respond_to do |format|
        format.any(:json, :js) do
          render :json => {:error => e.message}
        end
      end
    end
  end
end

Making these changes to your controller can help you with your requirements. You don't need a view after doing this.