JasonStructs

A Jason plugin library that adds the ability to encode and decode structs to and from JSON.

Uses the brilliant library Typed Struct to define a DSL for defining structs convertable to JSON in Elixir.

It adds to Jason the ability to convert these types of structs.

Installation

It is available in Hex, so the package can be installed by adding jason_structs to your list of dependencies in mix.exs:

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

Examples

We can define structs like this (see the tests):

defmodule Country do
  use Jason.Structs.Struct

  jason_struct do
    field(:code, String.t(), enforce: true)
    field(:name, String.t(), enforce: true)
  end
end

defmodule Address do
  use Jason.Structs.Struct

  jason_struct do
    field(:city, String.t(), enforce: true)
    field(:street_address_line_one, String.t(), enforce: true)
    field(:street_address_line_two, String.t(), enforce: false, excludable: true)
    field(:post_code, String.t(), enforce: false)
    field(:country, Country.t(), enforce: true)
  end
end

defmodule Interest do
  use Jason.Structs.Struct

  jason_struct do
    field(:name, String.t(), enforce: true)
    field(:description, String.t(), enforce: true)
  end
end

defmodule User do
  use Jason.Structs.Struct

  jason_struct do
    field(:name, String.t(), enforce: true)
    field(:age, integer(), enforce: true)
    field(:sex, :male | :female, enforce: true, default: :female)
    field(:address, Address.t(), enforce: true)
    field(:interests, list(), excludable: true, default: [])
    field(:children, [User.t()], excludable: true)
    field(:likes_json_structs, boolean(), default: true)
  end
end

And if we have instances of these structs like these:

    ivancho = %User{
      name: "Ivan Petrov",
      age: 10,
      sex: :male,
      address: %Address{
        city: "Yambol",
        street_address_line_one: "jk. Graph Ignatiev",
        street_address_line_two: "bl. 72",
        post_code: "8600",
        country: %Country{
          code: :bg,
          name: "Bulgaria"
        }
      },
      interests: [
        %Interest{name: "Call Of Duty", description: "A FPS!"},
        %Interest{name: "Minecraft", description: "Blocks and stuff!"}
      ],
      likes_json_structs: false
    }

    pesho = %User{
      name: "Petur Petrov",
      age: 35,
      sex: :male,
      address: %Address{
        city: "Yambol",
        street_address_line_one: "jk. Graph Ignatiev",
        street_address_line_two: "bl. 72",
        post_code: "8600",
        country: %Country{
          code: :bg,
          name: "Bulgaria"
        }
      },
      interests: [
        %Interest{
          name: "football",
          description: "Some people running after a ball and kicking it."
        },
        %Interest{name: "rakia", description: "Alcoholic bevarage, very loved on the Balkans."},
        %Interest{name: "salata", description: "Obicham shopskata salata, mastika ledena da pia."}
      ],
      children: [ivancho],
      likes_json_structs: false
    }

We can just do {ok, json} = Jason.encode(pesho) to get:

{
  "address": {
    "city": "Yambol",
    "country": {
      "code": "bg",
      "name": "Bulgaria"
    },
    "postCode": "8600",
    "streetAddressLineOne": "jk. Graph Ignatiev",
    "streetAddressLineTwo": "bl. 72"
  },
  "age": 35,
  "children": [
    {
      "address": {
        "city": "Yambol",
        "country": {
          "code": "bg",
          "name": "Bulgaria"
        },
        "postCode": "8600",
        "streetAddressLineOne": "jk. Graph Ignatiev",
        "streetAddressLineTwo": "bl. 72"
      },
      "age": 10,
      "interests": [
        {
          "description": "A FPS!",
          "name": "Call Of Duty"
        },
        {
          "description": "Blocks and stuff!",
          "name": "Minecraft"
        }
      ],
      "likesJsonStructs": false,
      "name": "Ivan Petrov",
      "sex": "male"
    }
  ],
  "interests": [
    {
      "description": "Some people running after a ball and kicking it.",
      "name": "football"
    },
    {
      "description": "Alcoholic bevarage, very loved on the Balkans.",
      "name": "rakia"
    },
    {
      "description": "Obicham shopskata salata, mastika ledena da pia.",
      "name": "salata"
    }
  ],
  "likesJsonStructs": false,
  "name": "Petur Petrov",
  "sex": "male"
}

And don't forget : YAMBOL IS THE CITY!