Dependency injection patterns in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is dependency injection in Vue?

Dependency injection in Vue is a way to pass data or services from a parent component to its descendants without using props or events. It helps share common resources easily.

beginner

Which Vue API is used for providing dependencies to child components?

The provide API is used in a parent component to supply dependencies that child components can access.

beginner

How do child components access injected dependencies in Vue?

Child components use the inject API to receive dependencies provided by an ancestor component.

intermediate

What is a practical example of using dependency injection in Vue?

Sharing a theme color or a global service like a logger across many components without passing props through every level.

intermediate

What is a limitation of Vue's provide/inject pattern?

It does not create reactive bindings by default, so changes in provided values are not automatically reactive unless wrapped in reactive() or ref().

Which Vue function is used to share data from a parent to descendants without props?

A ref

B inject

C emit

D provide

The provide function shares data down the component tree, while inject is used to receive it.

How does a child component receive a dependency in Vue?

A Using inject

B Using provide

C Using props

D Using emit

Child components use inject to access dependencies provided by ancestors.

What must you do to make provided values reactive in Vue?

A Wrap them in reactive() or ref()

B Use computed properties

C Use emit to update them

D Nothing, they are reactive by default

Wrapping provided values in reactive() or ref() makes them reactive and updates propagate.

Which of these is NOT a benefit of dependency injection in Vue?

A Shares global services easily

B Automatically makes data reactive

C Avoids prop drilling

D Simplifies component communication

Dependency injection does not automatically make data reactive; you must wrap it yourself.

What is a common use case for Vue's provide/inject pattern?

A Passing event handlers down

B Direct DOM manipulation

C Sharing theme or config data

D Fetching data from APIs

Provide/inject is great for sharing theme or configuration data across many components.

Explain how dependency injection works in Vue using provide and inject.

Think about how a parent can share something without passing props step-by-step.

Describe a real-life example where you would use dependency injection in a Vue app.

Imagine you want many parts of your app to use the same setting without passing it everywhere.