Behaviour and dispatch for shorthand expansion.

LiveStyle supports three built-in behaviors for handling CSS shorthand properties:

• LiveStyle.ShorthandBehavior.AcceptShorthands (default) - Keeps shorthand properties with nil resets
• LiveStyle.ShorthandBehavior.FlattenShorthands - Expands shorthands to their longhand equivalents
• LiveStyle.ShorthandBehavior.ForbidShorthands - Forbids disallowed shorthand properties at compile time

You can also provide a custom module that implements this behaviour.

Configuration

# Using atom shortcuts
config :live_style,
  shorthand_behavior: :accept_shorthands

# Using module directly
config :live_style,
  shorthand_behavior: LiveStyle.ShorthandBehavior.FlattenShorthands

# Custom behavior with options
config :live_style,
  shorthand_behavior: {MyCustomBehavior, strict: true}

Implementing a Custom Behavior

To implement a custom behavior, create a module that implements the LiveStyle.ShorthandBehavior behaviour. Property keys are CSS strings (e.g., "margin-top", "background-color").

defmodule MyCustomBehavior do
  @behaviour LiveStyle.ShorthandBehavior

  @impl true
  def expand_declaration(css_property, value) do
    # Return list of {css_property_string, value} tuples
    [{css_property, value}]
  end

  @impl true
  def expand_shorthand_conditions(css_property, conditions) do
    # Return list of {css_property_string, conditions_map} tuples
    [{css_property, conditions}]
  end
end