# Accent
## Installation
This package can be installed by adding `accent` to your list of dependencies in
`mix.exs`:
```elixir
def deps do
[{:accent, "~> 1.0"}]
end
```
Please note that you will need to provide `accent` with a JSON codec. Both
[`poison`](https://github.com/devinus/poison) and
[`jason`](https://github.com/michalmuskala/jason) are supported.
## 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.Case.Camel` (e.g. `camelCase`)
* `Accent.Case.Pascal` (e.g. `PascalCase`)
* `Accent.Case.Snake` (e.g. `snake_case`)
If no transformer is provided then `Accent.Case.Snake` 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 '{"hello": "Accent"}'
```
a router with this configuration:
```elixir
plug Plug.Parsers, parsers: [:urlencoded, :multipart, :json],
pass: ["*/*"],
json_decoder: Jason
plug Accent.Plug.Request
```
could expect to receive a `conn.params` value of:
```elixir
%{"hello" => "Accent"}
```
### `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 a default
case defined by `:default_case` will be used. If no default case is provided
then no conversion will happen. By default the supported cases are `camel`,
`pascal` and `snake`.
## Options
* `:default_case` - module used to case the response when the client does not
request a case or requests an unsupported case. When not provided then no
conversation will happen for the above scenarios. Defaults to `nil`.
* `:header` - the HTTP header used to determine the case to convert the
response body to before sending the response (default: `Accent`)
* `:json_codec` - module used to encode and decode JSON. The module is
expected to define `decode/1` and `encode!/1` functions (required).
* `:supported_cases` - map that defines what cases a client can request. By
default `camel`, `pascal` and `snake` are supported.
**Example**
```
plug Accent.Plug.Response, default_case: Accent.Case.Snake,
header: "x-accent",
supported_cases: %{"pascal" => Accent.Case.Pascal},
json_codec: Jason
```
Given this request:
```
curl -X POST https://yourapi.com/endpoints \
-H "Content-Type: application/json" \
-H "Accent: camel" \
-d '{"hello": "Accent"}'
```
with this router:
```elixir
defmodule MyAPI.Router do
use Plug.Router
plug Accent.Plug.Response, json_codec: Jason
post "/" do
send_resp(conn, 200, Jason.encode!(%{hello_back: "Anthony"}))
end
end
```
a client could expect a JSON response of:
```json
{
"helloBack": "Anthony"
}
```
## Contributors
A special thanks to all of our contributors!
* [@anthonator](https://github.com/anthonator)
* [@maxsalven](https://github.com/maxsalven)
* [@szajbus](https://github.com/szajbus)
