File Size for Ecto

Provides types for file sizes that you can use in your Ecto schemata.

This library uses file_size under the hood that brings a file size parser, formatter and allows calculation and comparison of file sizes with different units.

Prerequisites

• Erlang 20 or greater
• Elixir 1.8 or greater

Installation

If available in Hex, the package can be installed by adding file_size_ecto to your list of dependencies in mix.exs:

def deps do
  [
    {:file_size_ecto, "~> 2.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/file_size_ecto.

Usage

Without Unit

The following unit-less types are available:

• FileSize.Ecto.Bit
• FileSize.Ecto.Byte

Write a migration to add or update your file size field. You can use :integer or :bigint as types. If you expect very large file sizes, :bigint is recommended of course.

defmodule MyProject.Migrations.AddFileSizeToMyTable
  use Ecto.Migration

  def up do
    alter table(:my_table) do
      add :file_size, :bigint
    end
  end
end

Update your schema:

defmodule MySchema do
  use Ecto.Schema

  schema "my_table" do
    # ...

    field :file_size, FileSize.Ecto.Byte
  end
end

You can store your file size like this:

record = Repo.get(MySchema, 123)

updated_record =
  record
  |> Echo.Changeset.change(file_size: FileSize.new(2, :mb))
  |> Repo.update!()

updated_record.file_size
# => #FileSize<"2000000 B">

Or, when working with user input:

updated_record
  record
  |> Echo.Changeset.cast(%{file_size: "4 KiB"}, [:file_size])
  |> Repo.update!()

updated_record.file_size
# => #FileSize<"4096 B">

Note that the file size is always converted to the base unit (bit or byte) when storing it in the database, because no unit information is available. Read the next section if you want to find out how to store the size unit together with the value.

With Unit

The following types with units are available:

• FileSize.Ecto.BitWithUnit
• FileSize.Ecto.ByteWithUnit

Write a migration to add or update your file size field. The value is stored in a :map field. This map contains the as bits or bytes and the unit.

defmodule MyProject.Migrations.AddFileSizeToMyTable
  use Ecto.Migration

  def up do
    alter table(:my_table) do
      add :file_size, :map
    end
  end
end

Update your schema:

defmodule MySchema do
  use Ecto.Schema

  schema "my_table" do
    # ...

    field :file_size, FileSize.Ecto.ByteWithUnit
  end
end

You can store your file size like this:

record = Repo.get(MySchema, 123)

updated_record =
  record
  |> Echo.Changeset.change(file_size: FileSize.new(2, :mb))
  |> Repo.update!()

updated_record.file_size
# => #FileSize<"2 MB">

Or, when working with user input:

updated_record
  record
  |> Echo.Changeset.cast(%{file_size: "4 KiB"}, [:file_size])
  |> Repo.update!()

updated_record.file_size
# => #FileSize<"4 KiB">

Docs

Documentation is available on HexDocs.