# `Chimeway.Rendering.Channel`
[🔗](https://github.com/jonlunsford/chimeway/blob/v1.0.0/lib/chimeway/rendering/channel.ex#L1)

Behaviour contract for channel-specific render validation.

Every channel render validator — built-in or host-defined — must implement
this behaviour. Declaring `use Chimeway.Rendering.Channel` injects
`@behaviour Chimeway.Rendering.Channel` so the Elixir compiler issues warnings
for typo'd or missing `validate/1` implementations.

## Usage

    defmodule MyApp.Channels.Slack do
      use Chimeway.Rendering.Channel

      @impl Chimeway.Rendering.Channel
      def validate(attrs) when is_map(attrs) do
        # Ecto.Changeset validation producing a stringified map
        {:ok, attrs}
      end

      def validate(_other) do
        {:error, :invalid}
      end
    end

## Contract

`validate/1` receives the raw render attrs map from the notifier's `rendering/2`
callback and must return `{:ok, stringified_map}` on success or
`{:error, %Ecto.Changeset{}}` on validation failure.

The returned map MUST have string keys (produced by `Atom.to_string/1`) so it
survives JSONB round-trips and Oban serialization without key-type drift.

# `validate`

```elixir
@callback validate(attrs :: map()) :: {:ok, map()} | {:error, Ecto.Changeset.t()}
```

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*Consult [api-reference.md](api-reference.md) for complete listing*