Map to what exactly, what shape of data do you want? If you want to decode a json object into an elixir map, you can use a json decoder, there are several.

The most popular is probably https://github.com/devinus/poison, with it your code would be like this:

resp = HTTPoison.get!(url)
json = Poison.decode!(resp)

Here, json is an elixir term, probably a map. So you’d be able to use it to populate your table.

You can’t do that directly, because you have list there. I will give you 4 example ways to achieve what you need:

1. Get first item using List.first/1 or last item using List.last/1
2. Get by specified index using Enum.at/2
3. Iterate over list and do something for every item in it using Enum.each/2 or Enum.map/2 (depends on what you need).
4. Find element which is interesting for you by using Enum.find/2

For example:

list = Poison.decode!(response.body)
first_item = List.first(list)
last_item = List.last(list)
n = 10
nth_item = Enum.at(list, n) # where n is integer
found_item = Enum.find(list, & &1["Payor"] == "ASMSI")

# Then you can fetch specified data as you wanted:
%{"InvoiceDetails" => invoicedetails} = first_item
%{"InvoiceDetails" => invoicedetails} = last_item
%{"InvoiceDetails" => invoicedetails} = nth_item
%{"InvoiceDetails" => invoicedetails} = found_item

# Or do something for every item in list

defmodule Example do
  def sample_each(list), do: Enum.each(list, &do_sample_each/1)

  defp do_sample_each(%{"InvoiceDetails" => invoicedetails}), do: IO.inspect(invoicedetails)

  def sample_map(list), do: Enum.map(list, &do_sample_map/1)

  defp do_sample_map(%{"InvoiceDetails" => invoicedetails}), do: invoicedetails
end

:ok = Example.sample_each(list) # debugs "InvoiceDetails" for every item
invoicedetails_list = Example.sample_map(list) # returns list of invoicedetails

I think it’s both. He’s struggling with creating an impossible pattern match in order to support an unworkable template structure.

Forgive me I’m still a beginner in Elixir and MVC. I’m more of an OOP peep (.NET to be exact) Perhaps, I’m having difficulty understanding but I’m willing to learn.

Anyway, a big thanks for the response and effort.

Is there an approach for a concern like this where a beginner like me can understand?

Just tell us whether our responses made sense to you, and if not, try your best to explain your thinking so we can take another try