elixir - returning a list gives (Poison.EncodeError) unable to encode value -

io.puts(inspect( contacts )) gives:

 [%hellotable.contact{__meta__: #ecto.schema.metadata<:loaded>,   id: 37,     inserted_at: #ecto.datetime<2015-10-22t12:50:43z>,   name: "gumbo", phone: "(801) 555-55555",   updated_at: #ecto.datetime<2015-10-22t12:50:43z>}] 

and view looks like:

defmodule hellotable.contactview   use hellotable.web, :view    def render("index.json", %{contacts: contacts})     io.puts(inspect( contacts ))     contacts   end  end 

as try render view get:

** (poison.encodeerror) unable encode value: {nil, "contacts"} 

you need either implement poison.encoder protocol hellotable.contact described in encoding ecto model json in elixir or return map render function using render_many/4:

defmodule hellotable.contactview   use hellotable.web, :view    def render("index.json", %{contacts: contacts})     render_many(contacts, __module__, "contact.json")   end    def render("contact.json", %{contact: contact})     %{       id: contact.id,       name: contact.name,       phone_number: contact.phone     }   end     end 

the above how json handled in phoenix json generators.