mirror of
https://github.com/wailsapp/wails.git
synced 2025-05-05 00:12:45 +08:00
63 lines
2.5 KiB
Markdown
63 lines
2.5 KiB
Markdown
## Events
|
|
|
|
In v3, there are 3 types of events:
|
|
|
|
- Application Events
|
|
- Window Events
|
|
- Custom Events
|
|
|
|
### Application Events
|
|
|
|
Application events are events that are emitted by the application. These events
|
|
include native events such as `ApplicationDidFinishLaunching` on macOS.
|
|
|
|
### Window Events
|
|
|
|
Window events are events that are emitted by a window. These events include
|
|
native events such as `WindowDidBecomeMain` on macOS. Common events are also
|
|
defined, so they work cross-platform, e.g. `WindowClosing`.
|
|
|
|
### Custom Events
|
|
|
|
Events that the user defines are called `WailsEvents`. This is to differentiate
|
|
them from the `Event` object that is used to communicate with the browser.
|
|
WailsEvents are now objects that encapsulate all the details of an event. This
|
|
includes the event name, the data, and the source of the event.
|
|
|
|
The data associated with a WailsEvent is now a single value. If multiple values
|
|
are required, then a struct can be used.
|
|
|
|
### Event callbacks and `Emit` function signature
|
|
|
|
The signatures events callbacks (as used by `On`, `Once` & `OnMultiple`) have
|
|
changed. In v2, the callback function received optional data. In v3, the
|
|
callback function receives a `WailsEvent` object that contains all data related
|
|
to the event.
|
|
|
|
Similarly, the `Emit` function has changed. Instead of taking a name and
|
|
optional data, it now takes a single `WailsEvent` object that it will emit.
|
|
|
|
### `Off` and `OffAll`
|
|
|
|
In v2, `Off` and `OffAll` calls would remove events in both JS and Go. Due to
|
|
the multi-window nature of v3, this has been changed so that these methods only
|
|
apply to the context they are called in. For example, if you call `Off` in a
|
|
window, it will only remove events for that window. If you use `Off` in Go, it
|
|
will only remove events for Go.
|
|
|
|
### Hooks
|
|
|
|
Event Hooks are a new feature in v3. They allow you to hook into the event
|
|
system and perform actions when certain events are emitted. For example, you can
|
|
hook into the `WindowClosing` event and perform some cleanup before the window
|
|
closes. Hooks can be registered at the application level or at the window level
|
|
using `RegisterHook`. Application level are for application events. Window level
|
|
hooks will only be called for the window they are registered with.
|
|
|
|
### Developer notes
|
|
|
|
When emitting an event in Go, it will dispatch the event to local Go listeners
|
|
and also each window in the application. When emitting an event in JS, it now
|
|
sends the event to the application. This will be processed as if it was emitted
|
|
in Go, however the sender ID will be that of the window.
|