Angular decorator

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <script type="text/javascript" charset="utf-8">
      window.AngularVersionForThisPlunker = 'latest'
    </script>
    <title>angular playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
  </body>

</html>

/* Styles go here */

Angular multi checkbox solution

var angularVersion;
if(window.AngularVersionForThisPlunker === 'latest'){
  angularVersion = ''; //picks up latest
}
else {
  angularVersion = '@' + window.AngularVersionForThisPlunker;
}

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    '@angular/core': 'npm:@angular/core'+ angularVersion + '/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common' + angularVersion + '/bundles/common.umd.js',
    '@angular/common/http': 'npm:@angular/common' + angularVersion + '/bundles/common-http.umd.js',
    '@angular/compiler': 'npm:@angular/compiler' + angularVersion  + '/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http' + angularVersion + '/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router' + angularVersion +'/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms' + angularVersion + '/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations' + angularVersion + '/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations' + angularVersion + '/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core' + angularVersion + '/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-testing.umd.js',
    '@angular/common/http/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-http-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler' + angularVersion + '/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http' + angularVersion + '/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router' + angularVersion + '/bundles/router-testing.umd.js',
    'tslib': 'npm:tslib@1.6.1',
    'rxjs': 'npm:rxjs',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app';

platformBrowserDynamic().bootstrapModule(AppModule)

//our root app component
import {Component, NgModule, VERSION} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
import { ConvertDates } from './convert-dates.decorator';

@Component({
  selector: 'my-app',
  template: `
    <div>
      <h2>Angular decorator</h2>
      <p> Source: {{param | json}}</p>
      <button (click)="convert()">Convert</button>
      <p> Source: {{converted | json}}</p>
    </div>
  `,
})
export class App {
  param: any = {
    startDate: new Date()
  };
  
  converted: any;
  
  convert() {
    this.dateToApi(this.param);
  }
  
  @ConvertDates
  private dateToApi(args: any) {
    this.converted = args;
  }
}

@NgModule({
  imports: [ BrowserModule ],
  declarations: [ App ],
  bootstrap: [ App ]
})
export class AppModule {}

import { filter, map, pipe, reduce, trace } from './fp.operators';

export function ConvertDates(target, key, descriptor) {
  // save a reference to the original method
  const originalMethod = descriptor.value;
  descriptor.value = function (...args) {
      return originalMethod.apply(
          this,
          // iterate over list of arguments and format them
          args.map(formatArgument)
      );
  };
  return descriptor;
}

// if a parameter is an object, iterate over date properties and convert to api format
// otherwise return parameter as is
const formatArgument = (arg) => isObject(arg)
    ? Object.assign({}, arg, formatDateProps(arg))
    : arg;
    
//pipe executes functions passing result of the previous function
//as an input to the next
const formatDateProps = pipe(
  // break object to key-value pairs
  toKeyValue,
  // filter out date properties only
  filter(dates),
  // convert dates to api format
  map(toApiDate),
  // convert properties back to an object
  convert(propsToObject)
);

const isObject = (obj) => obj && typeof obj === 'object';
const toKeyValue = (obj) => Object.keys(obj).map(key => ([key, obj[key]]));
const dates = ([key, value]) => value && value instanceof Date;
const toApiDate = ([key, value]) => ([key, formatDate(value)]);
const propsToObject = (src, [key, value]) => Object.assign(src, { [key]: value });
const convert = (fn) => reduce(fn, {});

function formatDate(date: Date): string {
  return (date.getMonth() + 1) + "/" + date.getDate() + "/" + date.getFullYear();
}

export const curry = fn => (...args) => fn.bind(null, ...args);

export const trace = curry((label, x) => {
    console.log(`== ${label}:  ${x}`);
    return x;
});

export const filter = curry((fn, array) => array.filter(fn));
export const map = curry((fn, array) => array.map(fn));
export const reduce = curry((fn, init, array: any[]) => array.reduce(fn, init));

export const pipe = (...fns) => x => fns.reduce((v, f) => f(v), x);