MapRewire

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Bulk rekey your maps. Simple bud. (☞ﾟ ヮ ﾟ)☞

Why?

Simply because I am super lazy, and writing out functions to take maps and convert them to different keys was boring (and irritating) me.

Stop writing defp from_x_to_y(data), do: %{ "another_id" => data["id"], "name" => data["title"] }.

TL;DR; Syntax

  1. Macro: content<~>transformation, content is your data, transformation is your rules.
  2. Content: Any map. BYOD.
  3. Transformation: from=>to. Left is the original key, right is the new key.

Getting started

1. Add as a dependency

def deps do
  [
    {:map_rewire, "~> 0.3.0"}
  ]
end

2. Download

$ mix deps.get

3 (Optionally). Want to see inside MapRewire?

Add to config.exs

config :map_rewire,
  debug?: true

4. Run!

$ iex -S mix

Usage

Running in iex

Inline example using a list transformation

 iex(1)> use MapRewire
 iex(2)> %{"id"=>"234923409", "title"=>"asdf"}<~>["title=>name", "id=>shopify_id"]
 {:ok,
   %{"id" => "234923409", "title" => "asdf"},
   %{"shopify_id" => "234923409", "name" => "asdf"}
 }

Inline example using a string transformation

 iex(1)> use MapRewire
 iex(2)> %{"id"=>"234923409", "title"=>"asdf"}<~>"title=>name id=>shopify_id"
 {:ok,
     %{"id" => "234923409", "title" => "asdf"},
   %{"shopify_id" => "234923409", "name" => "asdf"}
 }

Mixed example with a string transformation

 iex(1)> use MapRewire
 iex(2)> content = %{
     "id"=>"234923409",
     "title"=>"asdf",
     "body_html"=>"asdf"
 }
 iex(3)> content<~>"title=>name id=>shopify_id body_html=>desc no_match=>wow_much_field"
 {:ok,
   %{"id" => "234923409", "title" => "asdf", "body_html" => "asdf"},
   %{"shopify_id" => "234923409", "name" => "asdf", "desc" => "asdf"}
 }

Dynamic example with a string transformation

 iex(1)> use MapRewire
 iex(2)> content = %{
     "id"=>"234923409",
     "title"=>"asdf",
     "body_html"=>"asdf"
 }
 iex(3)> transformation = "title=>name id=>shopify_id body_html=>desc no_match=>wow_much_field"
 iex(4)> content<~>transformation
 {:ok,
   %{"id" => "234923409", "name" => "title", "body_html" => "asdf"},
   %{"shopify_id" => "234923409", "name" => "asdf", "desc" => "asdf"}
 }

Dynamic example with a list transformation

 iex(1)> use MapRewire
 iex(2)> content = %{
     "id"=>"234923409",
     "title"=>"asdf",
     "body_html"=>"asdf"
 }
 iex(3)> transformation = ["title=>name", "id=>shopify_id", "body_html=>desc"]
 iex(4)> content<~>transformation
 {:ok,
   %{"id" => "234923409", "name" => "asdf", "body_html" => "asdf"},
     %{"shopify_id" => "234923409", "name" => "asdf", "desc" => "asdf"}
 }

Running as part of a module

Example 1:

defmodule Foo do
  use MapRewire

  @becomes [
    "id=>shopify_id",
    "title=>name",
    "body_html=>description"
  ]

  def bar do
    fake_factory
    |> final
  end

  defp fake_factory do
    %{
      "id" => "234923409",
      "title" => "asdf",
      "body_html" => "asdfasdf"
    }
  end

  def final(data) do
    data<~>@becomes
  end
end

Calling Foo.bar() will result in the output:

 {:ok,
   %{"id" => "234923409", "title" => "asdf", "body_html" => "asdfasdf"},
   %{"shopify_id" => "234923409", "name" => "asdf", "description" => "asdfasdf"}
 }

Example 2:

defmodule Foo do
  use MapRewire

  @becomes "age=>years_old languages=>technologies_known name=>this"

  def bar do
    fake_factory
    |> final
  end

  defp fake_factory do
    %{
      "age"=> 31,
      "languages"=> ["Erlang", "Ruby", "Elixir"],
      "name"=> "John"
    }
  end

  def final(data) do
    data<~>@becomes
  end
end

Calling Foo.bar() will result in the output:

{:ok,
   %{"age" => 31, "languages" => ["Erlang", "Ruby", "Elixir"], "name" => "John"},
   %{"years_old" => 31, "technologies_known" => ["Erlang", "Ruby", "Elixir"], "this" => "John"}
 }

Contributors

byjordhalostatue
byjordhalostatue