Attribrutex

Configure custom fields dynamically on your Phoenix models

Installation

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

def deps do
  [{:attribrutex, "~> 0.1.0"}]
end

2. Configure Attribrutex to use your repo in config/config.exs:

config :attribrutex, repo: ApplicationName.Repo

3. Install your dependencies:

mix deps.get

4. Generate the migrations:

mix attribrutex.install

5. Run the migrations:

mix ecto.migrate

6. Generate necessary migration for each table where you want to allow dinamyc fields and run it:

mix attribrutex.migrate <table_name>
mix ecto.migrate

7. Add the field to the schema in your models:

field :custom_fields, :map, default: %{}

Usage

Attribrutex works with three basic functions:

Creating a new field

Using create_custom_field(key, type, module, opts \\ [] you can create a new field for a specific module

i.e.:

Attribrutex.create_custom_field("location", :string, User)

As you can see you can specify a set of supported data types:

• :string
• :integer
• :boolean
• :float

If you need to create a field on specific context, for example, you need every user to have their own fields, not accessible for any other user, then, you can use the opts to make the new field belongs to a specific resource:

Attribrutex.create_custom_field("location", :string, Job,
                                 context_id: 1, context_type: "User")

After that, you will have a "location" string field on the Job model and only accessible by the user with the id 1

Listing fields

Use list_custom_fields_for(module, opts \\ %{}) to list the fields for a module. If you want to get the fields for a context you can use opts field and set a :context_id and :context_type keys.

It also supports a :mode param to return the fields in different ways:

• :keys - Only returns the key values for every entry.
• :fields - Returns a list of maps with :key and type keys

If :mode key doesn't exist, all the struct will be returned.

Adding new values to the custom fields

You can use prepare_custom_fields(changeset, params, opts \\ %{}) to add the changes to your changeset.

We recommend adding the function to your changeset function to deal with custom_fields:

defmodule AttribrutexUser do
  use Ecto.Schema
  import Ecto.Changeset

  schema "users" do
    field :email, :string
    field :custom_fields, :map, default: %{}

    timestamps()
  end

  def changeset(struct, params \\ %{}, opts \\ %{}) do
    struct
    |> cast(params, [:email])
    |> validate_required([:email])
    |> Attribrutex.prepare_custom_fields(params, opts)
  end
end

In case that a param value doesn't match with the type, an error will be set on the changeset:

#Ecto.Changeset<action: nil, changes: %{email: "example@example.com"},
errors: [custom_fields: {"Bad data type", [custom_field: :location]}],
data: #AttribrutexUser<>, valid?: false>

Usage example

Here we expose a full workflow example where we create a field, list it and add some value.

Attribrutex.create_custom_field("sample", :string, AttribrutexUser)
# {:ok,
#   %Attribrutex.CustomField{__meta__: #Ecto.Schema.Metadata<:loaded, "custom_fields">,
#     context_id: nil, context_type: nil, field_type: :string,
#     fieldable_type: "AttribrutexUser", id: 1231,
#     inserted_at: ~N[2017-07-20 13:08:35.134738], key: "sample",
#     updated_at: ~N[2017-07-20 13:08:35.134761]}}

Attribrutex.list_custom_fields_for(AttribrutexUser)
# [%Attribrutex.CustomField{__meta__: #Ecto.Schema.Metadata<:loaded, "custom_fields">,
#   context_id: nil, context_type: nil, field_type: :string,
#   fieldable_type: "AttribrutexUser", id: 1248,
#   inserted_at: ~N[2017-07-20 13:14:25.997483], key: "sample",
#   updated_at: ~N[2017-07-20 13:14:25.997505]}]

Attribrutex.list_custom_fields_for(AttribrutexUser, %{mode: :fields})
# [%{key: "sample", type: :string}]

Attribrutex.list_custom_fields_for(AttribrutexUser, %{mode: :keys})
# ["sample"]

AttribrutexUser.changeset(%AttribrutexUser{}, %{email: "example@example.com", location: "Paris"})
# Ecto.Changeset<action: nil,
#  changes: %{custom_fields: %{location: "Madrid"}, email: "asdf@asdf.com"},
#  errors: [], data: #AttribrutexUser<>, valid?: true>

Testing

Clone the repo and fetch dependencies with mix deps.get

Executing mix test should run all the tests.

License

See LICENSE