Rails - How to render json with extra field in index controller method - ruby-on-rails

Question

I'm using Rails 4.0.2 with paperclip for image upload in my project. Also I need to send a full image path of paperclip. So I can do it with add new field and set image path manually in my show controller method for particular record.
show
def show
respond_to do |format|
format.html
format.json { :json => JSON::parse(#demo.to_json.merge("new_field" => #demo.image_url.url).to_json}
end
end
When I view Json for any of my record, this is will showing good.
{
id: "1",
name: "demo",
new_field: "/demo/1/original/file.jpg"
}
In same scenario, I need to get the full image path of paperclip image for all records when I am requesting to index method on controller
index
def index
#demos = Demo.all
respond_to do |format|
format.html
format.json { :json => Demo.all.to_json}
end
end
I tried some of codes, but I don't know how exactly to write
def index
#demos = Demo.all
#demos.each do |demo|
new_field = {"new_field" => #demo.image_url.url}
# After I stucked with logic, how to uppend with 'demo'.
end
respond_to do |format|
format.html
format.json { :json => Demo.all.to_json}
end
end
How do I iterate my individual Demo model and How to merge full image path into each record.

Answer 1

I found the solution for my question,
def index
#demos = Demo.all
#demos_data = []
#demos.each do |demo|
new_field = {"new_field" => #demo.new_field.url}
demo = JSON::parse(demo.to_json).merge(new_field)
#demos_data << demo
end
respond_to do |format|
format.html
format.json { :json => #demos_data}
end
end

Answer 2

I suggest you to use two approaches, 1)use active model serializer to expose json response. 2) use jbuilder library to expose custom fields. Still you need help please let me know.

Answer 3

Try this:-
def index
#demos = Demo.all
#demos_data = []
#demos.each do |demo|
demo["new_field"] = #demo.image_url.url
#demos_data << demo
end
respond_to do |format|
format.html
format.json { :json => #demos_data}
end
end

Answer 4

maybe you can try:
def index
#demos = Demo.all
#demos.map do |demo|
new_field = {"new_field" => #demo.image_url.url}
demo.attributes.merge(new_field)
end
respond_to do |format|
format.html
format.json { :json => #demos}
end
end
attributes method returns a hash of all the object attributes, just need merge new key-value into the returned hash.

Answer 5

Another way of doing it is in your controller where you are rendering the json
render json: #merchants,
include: {
offers: {
except: [:created_at, :updated_at],
include: {
categories: {
except: [:created_at, :updated_at]
}
}
},
location: {
methods: :country_name,
except: [:created_at, :updated_at]
}
},
except: [:created_at, :updated_at]
Note the methods: :country_name, there you can render methods from your model as json attributes. and through include: ... you can eager load and render related models.