I am looking to display an error message in a jbuilder view. For instance, one route I might have might be:
/foos/:id/bars
If :id submitted by the user does not exist or is invalid, I'd like to be able to display the error message accordingly in my index.json.builder file.
Using Rails, what's the best way to get this done? The controller might have something such as:
def index
@bar = Bar.where(:foo_id => params[:id])
end
In this case, params[:id] might be nil, or that object might not exist. I'm not sure whether the best thing to do here is handle it in the controller and explicitly render an error.json.builder, or handle it in the index.json.builder view itself. What's the correct way to do this and if it's in the index.json.builder, is params[:id] available to check there? I know I can see if @bar.nil? but not sure on the inverse?