Trigger and state definitions in Angular - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a trigger in Angular animations?

A trigger in Angular animations is a named set of states and transitions that control how an element animates when its state changes.

beginner

Explain what a state means in Angular animation triggers.

A state defines a named style configuration for an element in an animation trigger. It describes how the element looks in that state.

intermediate

How do you define a trigger with states in Angular animations?

You use the trigger function with a name and an array of state and transition definitions to describe animation behavior.

intermediate

What role do transitions play in trigger and state definitions?

Transitions define how the animation moves between states, specifying the animation timing and styles during the change.

advanced

Give an example of a simple trigger with two states in Angular.

Example:<br>trigger('openClose', [<br> state('open', style({ height: '200px', opacity: 1 })),<br> state('closed', style({ height: '100px', opacity: 0.5 })),<br> transition('open <=> closed', [animate('0.5s ease-in-out')])<br>])

What does an Angular animation trigger primarily control?

A The CSS styles outside animations

B The HTML structure of a component

C The name and behavior of animation states and transitions

D The routing between pages

A trigger controls the named animation states and transitions that define how an element animates.

In Angular animations, what does a state define?

A The component lifecycle hook

B The timing of an animation

C The event that triggers the animation

D The style configuration of an element in that state

A state defines the style properties an element has when in that named state.

Which function is used to create an animation trigger in Angular?

A trigger()

B state()

C transition()

D animate()

The trigger() function defines an animation trigger with states and transitions.

What does a transition specify in Angular animations?

A The initial style of an element

B How to move between two states with animation

C The component selector

D The data binding syntax

Transitions define the animation steps and timing when moving between states.

Which of the following is a valid state definition in Angular animations?

A state('active', style({ opacity: 1 }))

B trigger('active', animate('1s'))

C transition('inactive => active')

D animate('1s ease')

state() defines a named style configuration; the other options are different animation parts.

Describe what a trigger and states are in Angular animations and how they work together.

Think about how you tell Angular when and how to animate an element.

Explain how you would create a simple open/closed animation using trigger and state definitions in Angular.

Imagine a panel that changes height and opacity when opened or closed.