https://github.com/malomohq/cocoon

Pure Elixir library for transforming data 🐛✨🦋
https://github.com/malomohq/cocoon

elixir-lang elixir-library made-by-malomo transform transformations transformer

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Pure Elixir library for transforming data 🐛✨🦋

• Host: GitHub
• URL: https://github.com/malomohq/cocoon
• Owner: malomohq
• License: mit
• Created: 2020-03-09T15:40:10.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2020-03-10T19:14:02.000Z (almost 5 years ago)
• Last Synced: 2024-04-14T16:58:52.919Z (9 months ago)
• Topics: elixir-lang, elixir-library, made-by-malomo, transform, transformations, transformer
• Language: Elixir
• Homepage:
• Size: 13.7 KB
• Stars: 3
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Cocoon

**Cocoon** is a pure [Elixir](http://elixir-lang.org/) library for transforming data 🐛✨🦋

## Installation

Cocoon is published on [Hex](https://hex.pm/packages/cocoon).

Add it to your list of dependencies in `mix.exs`;

```elixir

defp deps do

  { :cocoon, "~> 1.0" }

end

```

## Usage

Pass a map-based dataset into `Cocoon.transform/2`, along with a list of a

mappings, and it will emerge in a new form:

```elixir

data =

  %{

    "currency" => "USD",

    "customer" => %{

      "email" => "[email protected]",

    },

    "notifications" => false,

    "number_of_items" => 3,

    "order_number" => 12

  }

mappings =

  [

    { :currency, ["currency"] },

    { :email, ["customer", "email"] },

    { :item_count, ["number_of_items"] },

    { :number, ["order_number"], &to_string/1 }

  ]

Cocoon.transform(data, mappings)

#=> %{

#=>   currency: "USD",

#=>   email: "[email protected]",

#=>   item_count: 3,

#=>   number: "12"

#=> }

```

One potential use case for Cocoon is to serve as a transformation layer between

the outside world and your application.

For example, you might transform the responses from an external API into a

format that is more predictable and consistent with the vocabulary in your app.

By doing this, you also impose a boundary that limits coupling to the external

data source.

### Mappings

Cocoon transforms data by using a set of user-specified mappings, i.e. a list

of instructions for how individual elements in the dataset should be changed.

A mapping can be either a 2 or 3-element tuple, corresponding to a specific

entry in the dataset:

* First element - destination key, i.e. "to key"

* Second element - path to existing key, i.e. "from key(s)"

* Third element (optional) - function to apply to value at existing key

_NOTE: A mapping must be provided for every key / value pair that you want to

be returned. In other words, the transformed dataset will only contain key /

value pairs that are explicitly defined by a mapping._

### Data Types

Cocoon currently provides support for transforming maps, or a list of maps, e.g.

a list of orders.

If a list of maps is provided, a list of maps will also be returned, with the

mappings applied to each element of the set.