# Accent
[](https://travis-ci.org/sticksnleaves/accent)
[](https://coveralls.io/github/sticksnleaves/accent?branch=master)
## Installation
This package can be installed by adding `accent` to your list of dependencies in
`mix.exs`:
```elixir
def deps do
[{:accent, "~> 0.1.0"}]
end
```
## Usage
This project provides two plugs for handling the conversion of JSON keys to
different cases: `Accent.Plug.Request` and `Accent.Plug.Response`
### `Accent.Plug.Request`
Transforms the keys of an HTTP request's params to the same or a different
case.
You can specify what case to convert keys to by passing in a `:transformer`
option.
Accent supports the following transformers out of the box:
* `Accent.Transformer.CamelCase` (e.g. `CamelCase`)
* `Accent.Transformer.PascalCase` (e.g. `pascalCase`)
* `Accent.Transformer.SnakeCase` (e.g. `snake_case`)
If no transformer is provided then `Accent.Transformer.SnakeCase` will be
used.
Please note that this plug will need to be executed after the request has
been parsed.
### Example
Given this request:
```
curl -X POST https://yourapi.com/endpoints \
-H "Content-Type: application/json" \
-d '{"helloWorld": "value"}'
```
a router with this configuration:
```elixir
plug Plug.Parsers, parsers: [:urlencoded, :multipart, :json],
pass: ["*/*"],
json_decoder: Poison
plug Accent.Plug.Request
```
could expect to receive a `conn.params` value of:
```elixir
%{"hello_world" => "value"}
```
### `Accent.Plug.Response`
Transforms the keys of an HTTP response to the case requested by the client.
A client can request what case the keys are formatted in by passing the case
as a header in the request. By default the header key is `Accent`. If the
client does not request a case or requests an unsupported case then no
conversion will happen. By default the supported cases are `camel`, `pascal`
and `snake`.
### Options
* `:header` - the HTTP header used to determine the case to convert the
response body to before sending the response (default: `Accent`)
* `:json_encoder` - module used to encode JSON. The module is expected to
define a `encode!/1` function for encoding the response body as JSON.
(required)
* `:json_decoder` - module used to decode JSON. The module is expected to
define a `decode!/1` function for decoding JSON into a map. (required)
* `:supported_cases` - map that defines what cases a client can request. By
default `camel`, `pascal` and `snake` are supported.
### Examples
Given this request:
```
curl -X POST https://yourapi.com/endpoints \
-H "Content-Type: application/json" \
-H "Accent: pascal" \
-d '{"helloWorld": "value"}'
```
with this router:
```elixir
defmodule MyAPI.Router do
use Plug.Router
plug Accent.Plug.Response, json_encoder: Poison,
json_decoder: Poison
post "/endpoints" do
send_resp(conn, 200, Poison.encode!(%{hello_world: "value"}))
end
end
```
a client could expect a JSON response of:
```json
{
"helloWorld": "value"
}
```
