# Ksuid [](https://travis-ci.org/girishramnani/elixir-ksuid)
ksuid is a zero dependency Elixir library for generating and parsing KSUIDs.
Read more about ksuid [here](https://segment.com/blog/a-brief-history-of-the-uuid/)
## How To
```elixir
iex> Ksuid.generate()
"0p9kxW1vWavpdq7VSgbv8piY0nr"
iex> Ksuid.parse("0p9kxW1vWavpdq7VSgbv8piY0nr")
{
:ok,
%DateTime{calendar: Calendar.ISO, day: 9, hour: 14, microsecond: {0, 0},
minute: 52, month: 6, second: 34, std_offset: 0, time_zone: "Etc/UTC",
utc_offset: 0, year: 2017, zone_abbr: "UTC"},
<<166, 90, 80, 117, 89, 88, 196, 168, 113, 163, 157, 217, 224, 51, 151, 227>>
}
```
## Example Ecto Usage
### Ecto Type
```elixir
defmodule EctoKsuid do
@behaviour Ecto.Type
# uses string/varchar as storage type.
def type, do: :string
def cast(ksuid) when is_binary(ksuid), do: {:ok, ksuid}
def cast(_), do: :error
@doc """
Same as `cast/1` but raises `Ecto.CastError` on invalid arguments.
"""
def cast!(value) do
case cast(value) do
{:ok, ksuid} -> ksuid
:error -> raise Ecto.CastError, type: __MODULE__, value: value
end
end
def load(ksuid), do: {:ok, ksuid}
def dump(binary) when is_binary(binary), do: {:ok, binary}
def dump(_), do: :error
# Callback invoked by autogenerate fields - this is all that really matters
# just passing around the binary otherwise.
@doc false
def autogenerate, do: Ksuid.generate()
end
```
### Usage in a Schema
`:inserted_at` is a virtual field that can be derived/loaded from the autogenerated `:id`
```elixir
defmodule TestSchema do
use Ecto.Schema
@primary_key {:id, EctoKsuid, autogenerate: true}
schema "test" do
field :name, :string
field :inserted_at, :utc_datetime, virtual: true
end
def inserted_at(%TestSchema{id: ksuid} = row) do
{:ok, time_stamp, _} = Ksuid.parse(ksuid)
%TestSchema{row | inserted_at: time_stamp}
end
end
```
#### Migration
Create `:id` as `:bytea`, and primary key - similary to usage with `:binary_id`
```elixir
def change do
create table(:test, primary_key: false) do
add :id, :string, primary_key: true, size: 26
add :name, :text
end
end
```
## TODO
- [x] Generate KSUID
- [x] Parsing KSUIDS
- [x] Decode BASE62 method
- [x] Write tests
- [ ] Write Documentation
## Installation
```elixir
def deps do
[{:ksuid, "~> 0.1.2"}]
end
```
## Credit
[Segmentio/ksuid](https://github.com/segmentio/ksuid)
