angular2react method can be simplified

[cozmy]

I want to start by saying that I really like what you've accomplished here. It's a really useful tool for those which want to gradually migrate an AngularJS project to the newer world.

I found that the angular2react can be a bit hard to use and thus I've created a wrapper function which simplifies the API so my team members would use it more comfortably. As you'll see, we don't need to pass the $injector and register the angular component ourselves. It's all done automatically

Here it is:

import { IComponentOptions, module } from 'angular';
import { angular2react } from 'angular2react';

// All converted components have to be registered, thus we create our own module in which we'll register the original ng components.
const ngModule = module('converted-ng-components', []);

let $injector;
ngModule.run(['$injector', $i => $injector = $i]);

export function myAngular2React<Props extends {}>(name: string, options: IComponentOptions) {
  ngModule.component(name, options);

  return angular2react<Props>(name, options, {
    // angular2react requires the $injector but doesn't actually use it until a component needs to be rendered.
    get get() {
      return $injector.get;
    }
  } as any);
}

export const convertedNgComponentsModuleName = ngModule.name;

If you think this approach is fine, I can make a pull request.

[Downchuck]

@cozmy Thanks for this one! Have y'all hit anything with hot reloading? I've successfully used this with storybook, which is a big help for dealing with some of our older components.

[Irev-Dev]

I'm using a similar approach, so we don't need to pass in the injector each time, though we've defined ours as a custom hook where it wraps angular2react in a useMemo so that it can be called at the start of functional components without making excessive calls to angular2react

it's not a big abstraction so I'm not 100% sure a PR is needed.

import { ComponentClass, useMemo } from 'react';
import { angular2react } from 'angular2react';
import * as angular from 'angular';

let $injector;
export function setInjector(_$injector) {
    $injector = _$injector;
}

export function useAngularComponent(
    angularComponentName: string,
    angularComponentDefinition: angular.IComponentOptions
): ComponentClass {
    if (!$injector) {
        throw new Error('Missing injector, you might have run this before angular was bootstrapped');
    }
    return useMemo(() => angular2react(angularComponentName, angularComponentDefinition, $injector), []);
}

[LuisAverhoff]

@cozmy How exactly do you use your myAngular2React function? From my understanding and after countless hours trying to render a very simple component template, a call to the module's component function i.e ngModule.component(name, options); should not be called in your myAngular2React function. All your angular components need to be registered before you bootstrap angular just like @bcherny is doing here https://github.com/bcherny/angular2react-demos/blob/master/multi-file/src/index.jsx#L24 else the component won't render its template. Unless I'm missing something?

I made a simple angular helper module for registering angular components, converting them to react components, services, routes. I liked the idea that @Irev-dev had with using useMemo to reduce the number of calls to angular2react so that is what I went with.

import { angular2react } from 'angular2react';
import { module, auto, ILocationProvider } from 'angular';
import { useMemo } from 'react';
import { AngularComponent } from './components';
import { AngularService } from './services';

export const root = module('root', ['']);
let $injector: auto.IInjectorService;

export const useAngularComponent = <Props extends {}>(component: AngularComponent) => {
    if (!$injector) {
        throw new Error('Missing injector, you might have run this before angular was bootstrapped');
    }

    return useMemo(() => angular2react<Props>(component.selector, component, $injector), []);
};

export const registerAngularComponents = (components: AngularComponent[]) => {
    for (const component of components) {
        root.component(component.selector, component);
    }
};

export const registerAngularServices = (services: AngularService[]) => {
    for (const service of services) {
        root.service(service.name, service.injectable);
    }
};

export const registerAngularConstants = (constants: AngularService[]) => {
    for (const constant of constants) {
        root.constant(constant.name, constant.injectable);
    }
};

export const registerAngularRoutes = (routes: Function[]) => {
    root.config(($locationProvider: ILocationProvider) => {
        $locationProvider.html5Mode({ enabled: true, requireBase: false });
    });

    for (const route of routes) {
        root.config(route);
    }
};

export const setInjector = (_$injector: auto.IInjectorService) => {
    $injector = _$injector;
};

I have a single bootstrapping function.

import { bootstrap, auto } from 'angular';
import {
    root,
    setInjector,
    registerAngularComponents,
    registerAngularServices,
    registerAngularConstants,
    registerAngularRoutes,
} from './helpers';
import constants from './constants';
import routes from './routes';
import components from './components';
import services from './services';

const bootstrapAngular = (callback: () => void) => {
    registerAngularConstants(constants);
    registerAngularRoutes(routes);
    registerAngularComponents(components);
    registerAngularServices(services);

    root.run([
        '$injector',
        (_$injector: auto.IInjectorService) => {
            setInjector(_$injector);
            callback();
        },
    ]);

    bootstrap(document.createElement('div'), [root.name]);
};

export default bootstrapAngular;

This is how my my main index.tsx looks.

import React from 'react';
import { render } from 'react-dom';
import './index.css';
import App from './App';
import bootstrapAngular from './-angular';
import * as serviceWorker from './serviceWorker';
import { makeServer } from './tests/Mocks/Server';

if (process.env.NODE_ENV === 'development') {
    console.log('calling makeServer');
    makeServer();
}

const bootstrapReact = () => {
    render(<App />, document.getElementById('app'));
};

bootstrapAngular(bootstrapReact);

// If you want your app to work offline and load faster, you can change
// unregister() to register() below. Note this comes with some pitfalls.
// Learn more about service workers: https://bit.ly/CRA-PWA
serviceWorker.unregister();