how to triger ngOnChanges programmatically

[gede sutarsa]

Dear , 

i'm new on angular 2 , and currently learning on directives . Based on this example https://angular.io/resources/live-examples/attribute-directives/ts/plnkr.html

in my understanding, on   file app/app.component.html

when i click on radio button for example green, it will set variable : color to "green". 

but when i programmatically replace variable color for with example : "red", 

why the ngOnChanges not called as it called with --> 

 (click)="color='cyan'"

 

is there is some way to change the class property and fire change notification 

thx before

best regards, 

 

[Sander Elias]

Hi Gede,

ngOnChanges is an event handler. The DOM fires that event on the moment it detects user intervention. If you are under program control, and you need the function to run, you can simply call it.

Regards

Sander