Angular Hot Module Replacement

> Angular-HMR
Hot Module Reloading for Webpack and Angular. All versions of Angular and Webpack will work with this module

npm install @angularclass/hmr

!hmr-state-dom

main.browser.ts
``typescript
import { removeNgStyles, createNewHosts, bootloader } from '@angularclass/hmr';

@NgModule({
bootstrap: [ App ],
declarations: [ App ],
imports: [
// Angular 2
BrowserModule,
FormsModule,
HttpModule,
RouterModule.forRoot([], {
useHash: true
}),
// app
appModule
// vendors
],
providers: []
})
class MainModule {
constructor(public appRef: ApplicationRef) {}
hmrOnInit(store) {
if (!store || !store.state) return;
console.log('HMR store', store);
console.log('store.state.data:', store.state.data)
// inject AppStore here and update it
// this.AppStore.update(store.state)
if ('restoreInputValues' in store) {
store.restoreInputValues();
}
// change detection
this.appRef.tick();
delete store.state;
delete store.restoreInputValues;
}
hmrOnDestroy(store) {
var cmpLocation = this.appRef.components.map(cmp => cmp.location.nativeElement);
// recreate elements
store.disposeOldHosts = createNewHosts(cmpLocation)
// inject your AppStore and grab state then set it on store
// var appState = this.AppStore.get()
store.state = {data: 'yolo'};
// store.state = Object.assign({}, appState)
// save input values
store.restoreInputValues = createInputTransfer();
// remove styles
removeNgStyles();
}
hmrAfterDestroy(store) {
// display new elements
store.disposeOldHosts()
delete store.disposeOldHosts;
// anything you need done the component is removed
}
}

export function main() {
return platformBrowserDynamic().bootstrapModule(MainModule)
// use hmrModule or the "@angularclass/hmr-loader"
.then((ngModuleRef: any) => {
// module global ref for webpackhmr
// Don't run this in Prod
return hmrModule(ngModuleRef, module);
});
}

// boot on document ready
bootloader(main);

`
bootloader is only needed to detect that the dom is ready before bootstraping otherwise bootstrap. This is needed because that dom is already ready during reloading.

Important Helpers

* removeNgStyles: remove angular styles
* createNewHosts and disposeOldHosts: recreate root elements for bootstrapping
* bootloader: boot on document ready or boot if it's already ready
* createInputTransfer and restoreInputValues: transfer input DOM state during replacement

Production

In production you only need bootloader which just does this:
`typescript
export function bootloader(main) {
if (document.readyState === 'complete') {
main()
} else {
document.addEventListener('DOMContentLoaded', main);
}
}
`
You would bootstrap your app the normal way, in production, after dom is ready. Also, in production, you should remove the loader:

___

@NGRX/platform (NGRX 4.x.x)

To hook into NGRX 4 you simply need to supply a reducer to set the state, and include it in your development metaReducers.
`typescript
// make sure you export for AoT
export function stateSetter(reducer: ActionReducer): ActionReducer {
return function(state: any, action: any) {
if (action.type === 'SET_ROOT_STATE') {
return action.payload;
}
return reducer(state, action);
};
}
`
In your root reducer you can do something like this to include it in your metaReducers.
You should access your environment here and only include this in development.
`typescript
/**
* By default, @ngrx/store uses combineReducers with the reducer map to compose
* the root meta-reducer. To add more meta-reducers, provide an array of meta-reducers
* that will be composed to form the root meta-reducer.
*/
export const metaReducers: ActionReducer[] = [stateSetter]
`
Simply supply the metaReducer to the StoreModule and your hmr is hooked in.
`typescript
StoreModule.forRoot(reducers, { metaReducers }),
``

enjoy — PatrickJS