Perspective. animate a component the first time it appears

I wanted to know how I can animate a component when it first appears on a page or in a view.
I’m using css to create the animation but I don’t know in which event to put the animation.
any idea please?

Can you give more information on the component you are animating and what you want it to do?

I have a docked window and inside I have some components (labels and svg). Then I want the components to have an input animation when the window opens.