# KeyConvert
[](https://travis-ci.org/smitparaggua/key_convert)
[](https://coveralls.io/github/smitparaggua/key_convert?branch=master)
`KeyConvert` adds convenience methods for transforming keys in `Map`s.
Transformations are done recursively by default.
## Installation
The package can be installed by adding `key_convert` to your list of
dependencies in `mix.exs`:
```elixir
def deps do
[
{:key_convert, "~> 0.2.0"}
]
end
```
## Basic Usage
### Snake Case
`snake_case` converts the keys into all lower case separated by an underscore.
`Atom` keys are converted into strings.
```elixir
KeyConvert.snake_case(%{
contactInfo: %{emailAddress: "email@example.com"}
})
# %{"contact_info" => %{"email_address" => "email@example.com"}}
```
### Camelize
`camelize` converts the keys into camel-case. `Atom` keys are converted into
strings. It will retain the case of the first letter.
```elixir
KeyConvert.camelize(%{
contact_info: %{email_address: "email@example.com"}
})
# %{"contactInfo" => %{"emailAddress" => "email@example.com"}}
```
### Rename
`rename` converts the keys via the `rename_map` which is used to
determine what keys are raplaced with. Keys that are not available
in the `rename_map` are unaffected.
```
KeyConvert.rename(
%{amount: 500, currency: "PHP"},
%{amount: :value} # rename_map
)
# %{value: 500, currency: "PHP"}
```
### Convert
`convert` provides a way to transform keys based on a function supplied
by the user. The transformer function should be able to take a key as an input
and return a new key which will be used for the converted `Map`.
```elixir
# converter function that appends the string ".changed"
append_change = fn key -> key <> ".changed" end
KeyConvert.convert(%{"total_amount" => 500}, append_change)
# %{"total_amount.changed" => 500}
```
