@ima/hmr-client
v19.0.0
Published
IMA.js hmr client used to connect app with error overlay.
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Readme
Apart from connecting to webpack-hot-middleware
SSE on the dev server, it initializes window.__IMA_HMR
object that serves as an API for proper handling of HMR on IMA.js applications and controling @ima/error-overlay
. It also manages rendering of the HMR Indicator icon in the lower right corner of the screen.
Description
The companion script is injected at the top of the entry points in the webpack configuration, which then initializes the event emitter, event source and indicator singletons on the window.__IMA_HMR
upon application load (see interface description below).
This client code directly replaces the ones used in webpack-hot-middleware
, however we are still using webpack-hot-middleware
on the server-side to send compilation events using SSE EventSource.
In combination with webpack-dev-middleware
(which sends hot*
update files to the application) and events from webpack-hot-middleware
SSE, the client is using the webpack's Hot Module API to apply new hot updates to the client's source code. Additionally, it proxies compilation errors to error overlay and manages the HMR indicator icon in the lower right corner.
Usage
Use this package as an entry point in your webpack configuration (ideally at the topmost position on every additional entry point separately!). You can also customize some additional configuration that is passed to the client during initialization. Only name
is required, other options have their defaults.
// webpack.config.js
module.exports = {
// ...
entry: {
client: [
`@ima/hmr-client?${new URLSearchParams({
name: 'client', // required
noInfo: 'false',
reload: 'true',
timeout: '3000',
reactRefresh: 'true',
port: '3101',
hostname: 'localhost',
publicUrl: 'http://localhost:3101',
}).toString()}`,
'./app/main.js',
]
}
// ...
}
These options should match the actual dev server configuration since the HMR client uses them to connect to the webpack-hot-middleware
event source.
window.__IMA_HMR
interface
import { Emitter } from '@esmj/emitter';
interface Window {
__IMA_HMR: {
emitter?: Emitter;
eventSource?: EventSourceWrapper;
indicator?: IndicatorWrapper;
};
}
emitter
Emitter
@esmj/emitter used to emit messages across application, error-overlay and hmr-client. It has 2 public methods:
on(eventName: EventName, listener: Listener): void;
- use to listen on events ('error' | 'clear' | 'close' | 'destroy'
)emit(eventName: EventName, data?: ListenerData): void;
- use to emit events, only'error'
event is expected to pass any data in following form{ error: {} }
.error
- Send error object to ErrorOverlay.clear
- Clear all currently displayed errors in ErrorOverlay.close
- Close ErrorOverlay externally.destroy
- Destroy IMA.js application (destroys current instance before new one is created during HMR).
eventSource
EventSourceWrapper
Singleton wrapper around webpack-hot-middleware
SSE EventSource. You can use addListener
public method to add custom listeners to the SSE events.
addListener(name: string, listener: EventSourceListener)
- wherename
corresponds to thename
value passed in webpack.config query params. This allows support for MultiComplier webpack instances.
indicator
IndicatorWrapper
Use to manage HMR State Indicator icon, has 2 public methods:
create(state: 'invalid' | 'loading' = 'loading'): void
- Adds icon to the DOM in on of the selected visual states.destroy(): void
- Removes Icon from the DOM.
This package is part of the IMA.js application stack, see imajs.io for more info about the whole project.