Angular2 - Set A Different Color to an element Depending On Value

Question

I am new to Angular2 and was wondering how I go about setting a font color to an element depending on the value.

My scenario is: if the value of the input field is not 100 then I want it red but if it is 100 then I want it green.

I have the following code in place but cant get it working.

XXX.component.css

.red {
    color: red; 
}

.green {
    color: green;
}

XXX.component.css

<input mdInput placeholder="Proportion '%'" [(ngModel)]="proportion ">
<p>hello <span ng-class='{red : proportion!= '100', green: proportion === '100'}'>{{proportion}}</span></p>

Answer 1

There are two solutions to change font color but depends on you requirement

1. If you requirement is change inline style then you can use angular NgStyle Directive which Update an HTML element styles for you..

NgStyle directive Ex:

<span [ngStyle]="{'color': proportion === '100' ? 'green' : 'red'}"></span>

        ---------------------- OR -----------------------------------

<span [style.color]="proportion === '100' ? 'green' : 'red'"></span>

2. If you requirement is change class then you can use angular NgClass Directive which Adds and removes CSS classes on an HTML element...

NgClass directive Ex:

<span [ngClass]="{proportion === '100' ? 'green': 'red'}"></span>

Answer 2

You can also bind the style property.

<span [style.color]="proportion === '100' ? 'green' : 'red'"></span>

Answer 3

You can use it like this:

 <div class="card template-card" [ngClass]="{'z-depth-3': template == selectedTemplate, 'not-selected': !(template == selectedTemplate) && selectedTemplate != null}">

Answer 4

Since you use Angular2, So you need to use [ngClass], and your input model is bind to proportion, So use it to compare,

Do it like :

<input mdInput placeholder="Proportion '%'" [(ngModel)]="proportion">
<p>hello <span [ngClass]="{'red': proportion !== '100', 'green': proportion === '100'}">{{username}}</span></p>