Translates legacy event shapes ({:tap, tag}, {:change, tag, value},
{:tap, {:list, id, :select, index}}) into the canonical
{:mob_event, %Address{}, event, payload} envelope.
This is a transitional helper: as long as the native NIF emits the legacy
register_tap-style messages, this module bridges them into the new model.
When the native side is migrated to emit the canonical envelope directly,
this module can be removed.
Usage from a screen
def handle_info(msg, socket) do
case Mob.Event.Bridge.legacy_to_canonical(msg, screen_module) do
{:ok, {:mob_event, addr, event, payload}} ->
# Handle via the new model
handle_event(addr, event, payload, socket)
:passthrough ->
# Not a recognised legacy shape — handle normally
...
end
endBridge rules
| Legacy shape | Canonical envelope |
|---|---|
{:tap, tag} (atom or arbitrary tag) | {:mob_event, addr(:button, tag), :tap, nil} |
{:tap, {:list, id, :select, index}} | {:mob_event, addr(:list, id, instance: index), :select, nil} |
{:change, tag, value} | {:mob_event, addr(:text_field, tag), :change, value} |
| other | :passthrough |
Widget kind defaults to :button for :tap, :text_field for :change,
and :list for the structured list-row tag. Callers that need a more
specific widget kind can extend the rule table.
Summary
Functions
Convert a legacy event shape to the canonical envelope.
Same as legacy_to_canonical/3 but raises if the message is not a
recognised legacy event. Useful in tests.
Types
@type result() :: {:ok, {:mob_event, Mob.Event.Address.t(), atom(), term()}} | :passthrough
Result of attempting to bridge a legacy message.
Functions
Convert a legacy event shape to the canonical envelope.
screen_id is used as the screen field on the address; it can be the
screen module atom, the screen pid, or any term. render_id, if known,
bumps the address's render generation; defaults to 1 if omitted.
Examples
iex> Mob.Event.Bridge.legacy_to_canonical({:tap, :save}, MyScreen)
{:ok, {:mob_event, %Mob.Event.Address{screen: MyScreen, widget: :button, id: :save, render_id: 1, component_path: [], instance: nil}, :tap, nil}}
iex> Mob.Event.Bridge.legacy_to_canonical({:tap, {:list, :contacts, :select, 47}}, MyScreen)
{:ok, {:mob_event, %Mob.Event.Address{screen: MyScreen, widget: :list, id: :contacts, instance: 47, render_id: 1, component_path: []}, :select, nil}}
iex> Mob.Event.Bridge.legacy_to_canonical({:change, :email, "user@example.com"}, MyScreen)
{:ok, {:mob_event, %Mob.Event.Address{screen: MyScreen, widget: :text_field, id: :email, render_id: 1, component_path: [], instance: nil}, :change, "user@example.com"}}
iex> Mob.Event.Bridge.legacy_to_canonical({:not_an_event, :something}, MyScreen)
:passthrough@spec legacy_to_canonical!(term(), term(), keyword()) :: {:mob_event, Mob.Event.Address.t(), atom(), term()}
Same as legacy_to_canonical/3 but raises if the message is not a
recognised legacy event. Useful in tests.