MapWithIndifferentAccess

Utility functions making it easier to work with maps which can either have atom keys or string keys, but never both.

For example, you'll find it useful when working with Ecto.Changeset, as Ecto.Changeset.cast/4 forbids passing maps with mixed key types.

Nearly all functions mimic Map interface, e.g. MapWithIndifferentAccess.put/3 works just as Map.put/3, with two important differences:

1. You need to use atom keys when calling the functions. (Even if the map uses string keys.)

2. If the map uses string keys, key argument will be converted to a string, and only then called with a respective Map function.

Usage

1. Add map_with_indifferent_access to your list of dependencies in mix.exs:

   def deps do
     [
       {:map_with_indifferent_access, "~> 1.0.0"}
     ]
   end
   

2. Whenever you are interacting with a map that can have either string or atom keys, instead of using Map.* functions such as Map.get or Map.put, use MapWithIndifferentAccess.* functions (e.g. MapWithIndifferentAccess.get MapWithIndifferentAccess.put.

   When referring to map keys, specify them as atoms (instead of strings).

   MapWithIndifferentAccess.get(%{a: 1}, :a) // # returns 1
   MapWithIndifferentAccess.get(%{"a" => 1}, :a) // # returns 1
   
   MapWithIndifferentAccess.put(%{a: 1}, :b, 2) // # returns %{a: 1, b: 2}
   MapWithIndifferentAccess.put(%{"a" => 1}, :b, 2) // # returns %{"a" => 1, "b" => 2}
   
   # Real world usage example
   defmodule ProductController do
     def create(conn, %{"name" => _name} = params) do
       params
       |> MapWithIndifferentAccess.put(:author_id, conn.assigns.current_user.id)
       |> ProductService.create()
     end
   end
   
   defmodule AdminController do
     def create_test_product(conn, params) do
       %{name: "test product"}
       |> MapWithIndifferentAccess.put(:author_id, conn.assigns.current_user.id)
       |> ProductService.create()
     end
   end
   

Documentation

See Hex docs.

Contributing

Running tests

Run the following after cloning the repo:

mix deps.get
mix test