67 lines
2.5 KiB
TypeScript
67 lines
2.5 KiB
TypeScript
import * as _ from 'lodash';
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import * as React from 'react';
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interface LazyComponentProps {
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reactComponentPromise: Promise<React.ComponentClass<any>>;
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reactComponentProps: any;
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}
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interface LazyComponentState {
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component?: React.ComponentClass<any>;
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}
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/**
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* This component is used for rendering components that are lazily loaded from other chunks.
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* Source: https://reacttraining.com/react-router/web/guides/code-splitting
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*/
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export class LazyComponent extends React.Component<LazyComponentProps, LazyComponentState> {
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constructor(props: LazyComponentProps) {
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super(props);
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this.state = {
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component: undefined,
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};
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}
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public componentWillMount() {
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// tslint:disable-next-line:no-floating-promises
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this._loadComponentFireAndForgetAsync(this.props);
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}
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public componentWillReceiveProps(nextProps: LazyComponentProps) {
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if (nextProps.reactComponentPromise !== this.props.reactComponentPromise) {
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// tslint:disable-next-line:no-floating-promises
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this._loadComponentFireAndForgetAsync(nextProps);
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}
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}
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public render() {
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return _.isUndefined(this.state.component)
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? null
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: React.createElement(this.state.component, this.props.reactComponentProps);
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}
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private async _loadComponentFireAndForgetAsync(props: LazyComponentProps) {
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const component = await props.reactComponentPromise;
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this.setState({
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component,
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});
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}
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}
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/**
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* [createLazyComponent description]
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* @param componentName name of exported component
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* @param lazyImport lambda returning module promise
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* we pass a lambda because we only want to require a module if it's used
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* @example `const LazyPortal = createLazyComponent('Portal', () => System.import<any>('ts/containers/portal'));``
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*/
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export const createLazyComponent = (componentName: string, lazyImport: () => Promise<any>) => {
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return (props: any) => {
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const reactComponentPromise = (async (): Promise<React.ComponentClass<any>> => {
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const mod = await lazyImport();
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const component = mod[componentName];
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if (_.isUndefined(component)) {
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throw new Error(`Did not find exported component: ${componentName}`);
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}
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return component;
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})();
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return <LazyComponent reactComponentPromise={reactComponentPromise} reactComponentProps={props} />;
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};
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};
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