how to use rails format.json [closed]

Question

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def index
@cellphones = Cellphone.all

respond_to do |format|
  format.html # index.html.erb
  format.json { render json: @cellphones }
end

• SIMPLE ANSWERS PLEASE...

  • what is format.json used for?

  • do I have to create a view for it?

  • how does it relate to javascrip?

  • how does it relate to to ajax?

  • please give a simple example of how to use it...

Answer 1

1. It's used to return JSON.
2. No, it renders @cellphones as JSON. You may create a view, though, for example, using a JSON builder to customize the output beyond what Rails provides out of the box.
3. JavaScript is often used to make JSON Ajax requests, like for client-side frameworks.
4. Ajax calls often want JSON as a result. They may also request HTML to render directly.
5. That is an example of how to use it; make an Ajax request to /cellphones.