Binding Angular CSS Classes Dynamically with @HostBinding

Scenario

Within our app component we wish to add a onValid CSS class whenever the _valid property on the component is true.

Approach

Within styles.css create the onValid CSS class.

.onValid {
color: aqua;
}

Decorate a isValid() getter with @HostBinding that will add the onValid CSS class to the component whenever the _valid property is true.

@HostBinding('class.onValid')
get isValid() {
return this._valid;
}
private _valid = true;

Demo

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