Dispatches an event by ID with data and variables.

This is the high-level dispatch function that applications use. It looks up the event module, creates channels, and dispatches to all of them.

Parameters

• event_id - The event identifier (e.g., "requests.new_reseller_request")
• data - Map of domain data (resources, users, etc.)
• variables - Map of template variables (tokens, simple values, etc.) - defaults to %{}

Returns

• {:ok, results} - List of delivery receipt results
• {:error, reason} - If event not found or dispatch fails

Data vs Variables

Use data for:

• Domain resources (User, Order, Ticket, etc.)
• Structured Ash resources
• Objects that need relationship traversal

Use variables for:

• Authentication tokens (reset_token, confirmation_token)
• Simple template values
• Computed values that don't need relationships

This separation prevents naming conflicts and makes the intent clearer.

Examples

# Dispatch with authentication token
AshDispatch.Dispatcher.dispatch(
  "accounts.password_reset",
  %{user: user},
  %{reset_token: token}
)

# Dispatch with invitation data
AshDispatch.Dispatcher.dispatch(
  "accounts.invited",
  %{invited_user: user, invited_by: admin},
  %{invitation_token: token, custom_message: message}
)

# Dispatch an order created event (no variables needed)
AshDispatch.Dispatcher.dispatch(
  "orders.created",
  %{order: order, user: user}
)

Low-level dispatch function that dispatches to a specific channel with a pre-built context.

This is used internally and by DSL-based events that build their own context. Most applications should use the high-level dispatch/2 or dispatch/3 functions instead.

Parameters

• context - Pre-built AshDispatch.Context struct
• channel - AshDispatch.Channel struct
• event_config - Event configuration map (with :module, :content, etc.)

Returns

• {:ok, receipt} - DeliveryReceipt if successful
• {:error, reason} - If dispatch fails