How to change text colour in Aurelia Dialog?

Question

I have a dialog as you can see here:

<template>
  <ux-dialog>
    <ux-dialog-body>
      <h2 t="luminaires.list.enter-serialnumber">Bitte geben Sie eine neue Seriennummer ein</h2>
      <input value.bind="serialNumber" />
    </ux-dialog-body>

    <ux-dialog-footer>
      <button click.trigger="controller.cancel()" t="luminaires.list.cancel">Abbrechen</button>
      <button click.trigger="controller.ok(serialNumber)" t="luminaires.list.ok">Ok</button>
    </ux-dialog-footer>
  </ux-dialog>
</template>

and related view-model:

import {DialogController} from "aurelia-dialog";
import {Controller} from "aurelia-templating";

export class SerialnumberDialog {
  private static inject = [DialogController];
  private serialNumber: string;
  private controller: any;
  constructor(controller: Controller) {
    this.controller = controller;
  }
}

I want to change the color of the following sentence sometimes.

<h2 t="luminaires.list.enter-serialnumber">Bitte geben Sie eine neue Seriennummer ein</h2>

For example when some body give a repetitious serial number, I want to change the colour to red. I can open the dialog through the following code:

this.dialogService.open({ viewModel: SerialnumberDialog, lock: false })
      .whenClosed((response) => {......

I want to use Aurelia concept for this purpose. Could you please tell me the solution?

Answer 1

I would use the css.bind method on the <h2> element. I would create a method on your view model to be able to decide whether you want the text to be red or not, and then store the styles in a css variable.

import {DialogController} from "aurelia-dialog";
import {Controller} from "aurelia-templating";

export class SerialnumberDialog {
  private static inject = [DialogController];
  private serialNumber: string;
  private controller: any;


  constructor(controller: Controller) {
    this.controller = controller;
    this.myCss = {
      color: 'black'
    };
  }

  activate(){
    if(//serial number is repetitious){
      this.myCss.color = red;
    }
  }
}

Now you have a myCss object which can be bound to your view to alter the colour of your text.

<h2 t="luminaires.list.enter-serialnumber" css.bind="myCss">
  Bitte geben Sie eine neue Seriennummer ein
</h2>

Dwayne Charrington does a great article on css binding on his ILikeKillNerds blog https://ilikekillnerds.com/2016/02/binding-with-style-in-aurelia/ if you want any more information.