Month: October 2019

Dynamically switch RTL/LTR on Kendo UI for Angular

This is working but not dynamically, so we need to change this to work 

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { LayoutModule } from '@progress/kendo-angular-layout';
import { RTL } from '@progress/kendo-angular-l10n';


import { AppComponent } from './app.component';

@NgModule({
  imports:      [ BrowserModule, BrowserAnimationsModule, LayoutModule ],

  // Enable Right-to-Left mode for Kendo UI components
  providers:    [{ provide: RTL, useValue: true }],

  declarations: [ AppComponent ],
  bootstrap:    [ AppComponent ]
})
export class AppModule { }

Use a factory provider to dynamically resolve values

export function enableRTL(): boolean {
  const x = document.cookie;
  const dir = getCookie('dir');

  if (dir === 'rtl') {
    return true;
  }
  return false;
}
{provide: RTL, useFactory: enableRTL}

References
https://www.telerik.com/kendo-angular-ui-develop/components/globalization/localization/
https://plnkr.co/edit/EOFoxuwc6ooUm5Ctho2q?p=preview
https://github.com/telerik/kendo-angular/issues/984

Sharing Modules in Angular

import { CommonModule } from '@angular/common';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { CustomerComponent } from './customer.component';
import { NewItemDirective } from './new-item.directive';
import { OrdersPipe } from './orders.pipe';

@NgModule({
 imports:      [ CommonModule ],
 declarations: [ CustomerComponent, NewItemDirective, OrdersPipe ],
 exports:      [ CustomerComponent, NewItemDirective, OrdersPipe,
                 CommonModule, FormsModule ]
})
export class SharedModule { }

References
https://angular.io/guide/sharing-ngmodules

Using ControlValueAccessor to Create Custom Form Controls in Angular

import { Component, forwardRef, HostBinding, Input } from '@angular/core';
import { ControlValueAccessor, NG_VALUE_ACCESSOR } from '@angular/forms';

@Component({
  selector: 'rating-input',
  template: `
    <span
      *ngFor="let starred of stars; let i = index"
      (click)="onTouched(); rate(i + (starred ? (value > i + 1 ? 1 : 0) : 1))">
      <ng-container *ngIf="starred; else noStar">⭐</ng-container>
      <ng-template #noStar>·</ng-template>
    </span>
  `,
  styles: [`
    span {
      display: inline-block;
      width: 25px;
      line-height: 25px;
      text-align: center;
      cursor: pointer;
    }
  `],
  providers: [
    {
      provide: NG_VALUE_ACCESSOR,
      useExisting: forwardRef(() => RatingInputComponent),
      multi: true
    }
  ]
})
export class RatingInputComponent implements ControlValueAccessor {

  stars: boolean[] = Array(5).fill(false);

  // Allow the input to be disabled, and when it is make it somewhat transparent.
  @Input() disabled = false;
  @HostBinding('style.opacity')
  get opacity() {
    return this.disabled ? 0.25 : 1;
  }

  // Function to call when the rating changes.
  onChange = (rating: number) => {};

  // Function to call when the input is touched (when a star is clicked).
  onTouched = () => {};

  get value(): number {
    return this.stars.reduce((total, starred) => {
      return total + (starred ? 1 : 0);
    }, 0);
  }

  rate(rating: number) {
    if (!this.disabled) {
      this.writeValue(rating);
    }
  }

  // Allows Angular to update the model (rating).
  // Update the model and changes needed for the view here.
  writeValue(rating: number): void {
    this.stars = this.stars.map((_, i) => rating > i);
    this.onChange(this.value)
  }

  // Allows Angular to register a function to call when the model (rating) changes.
  // Save the function as a property to call later here.
  registerOnChange(fn: (rating: number) => void): void {
    this.onChange = fn;
  }

  // Allows Angular to register a function to call when the input has been touched.
  // Save the function as a property to call later here.
  registerOnTouched(fn: () => void): void {
    this.onTouched = fn;
  }

  // Allows Angular to disable the input.
  setDisabledState(isDisabled: boolean): void {
    this.disabled = isDisabled;
  }

}

References
https://alligator.io/angular/custom-form-control/
https://blog.thoughtram.io/angular/2016/07/27/custom-form-controls-in-angular-2.html