StructInspect

StructInspect is a configurable library to customize struct and map inspection in Elixir. It allows you to omit fields with "empty" values, producing cleaner and more readable output.

For more details and advanced usage and configuration examples, please read the Usage Guide.

Installation

The package can be installed by adding struct_inspect to your list of dependencies in mix.exs:

def deps do
  [
    {:struct_inspect, "~> 0.1.4"}
  ]
end

Usage

To enable StructInspect for a particular struct, you just use StructInspect in your module definition.

defmodule MyStruct do
  use StructInspect

  defstruct [:id, :name, :bio, :email]
end

By default, StructInspect will omit fields with nil values, empty strings, empty lists, and empty structs.

iex> struct = %MyStruct{id: 1, name: "Gemini", bio: nil, email: ""}
%MyStruct{id: 1, name: "Gemini"}

Configuration

The behavior of StructInspect is determined by a set of options that can be provided at different levels. The core of the configuration is the StructInspect.Opts module, which defines all the available options and their default values. Please refer to the StructInspect.Opts module documentation for the most up-to-date list of defaults.

You can customize the inspection behavior on a per-struct basis by passing options to the use StructInspect macro. You can pass a map, a keyword list, or a list of atoms.

For example, if you want to also omit fields with false values, you can do:

defmodule MyConfiguredStruct do
  use StructInspect, false_value: true

  defstruct [:id, :name, :is_active]
end

iex> struct = %MyConfiguredStruct{id: 1, name: "Gemini", is_active: false}
%MyConfiguredStruct{id: 1, name: "Gemini"}

When a list of atoms is provided, ONLY the named keys will be set to true and the rest to false, overriding all the defaults.

defmodule MyOtherStruct do
  use StructInspect, [:false_value, :true_value]

  defstruct [:id, :name, :is_active, :is_legacy]
end

Application-wide Configuration

You can also configure the default options for StructInspect application-wide in your config/config.exs file.

# This setting will be merged to the defaults in `StructInspect.Opts`.
config :struct_inspect,
  ommits: [
    nil_value: true,
    empty_string: true,
    false_value: true
  ]

# This setting will produce a `StructInspect.Opts` set with only nils, empty maps and zero integers enabled.
config :struct_inspect,
  ommits: [:nil_value, :empty_map, :zero_integer]

The options passed to use StructInspect will be merged with the application-wide configuration. The options passed directly to use have precedence.

Available Options

The following options are available in StructInspect.Opts:

• nil_value: Omits nil values. (default: true)
• zero_integer_value: Omits 0. (default: false)
• zero_float_value: Omits 0.0. (default: false)
• empty_string: Omits "". (default: true)
• empty_list: Omits []. (default: true)
• empty_map: Omits %{}. (default: true)
• empty_struct: Omits empty structs. (default: true)
• empty_tuple: Omits {}. (default: true)
• true_value: Omits true. (default: false)
• false_value: Omits false. (default: false)
• except: List of keys to omits. (default: [:__struct__])

License

StructInspect is released under the MIT License. See the LICENSE file for more details.