Vuejs Mutating Object Passed As A Prop

If I'm passing (a reference to) an Object as a prop is it OK to mutate values in the prop? I'm developing a web app which will require a lot of values to be passed to a component,

Solution 1:

Is mutating a prop bad practice?

Yes absolutely. In more complex applications it is very easy to lose track of where/what/why is mutated

What is the right way to handle state across different components?

In small projects you can really do whatever you want, because you will most likely be able to follow the logic - even after not looking at the project for a year. The possibilities include:

1. Mutating Props (ugly but will work)
2. Using Events to mutate state in parent components; take a look at the EventBus (better)
3. Use global shared state; look at Vuex (best, but a little more boilerplate)

In big projects, however, you should absolutely use Vuex. It is a module for Vue that adds global shared state to your app, which you can access and mutate from all places in your app.

Solution 2:

I think I understand what you are trying to do, You want to pass data to a child component, mutate it and then give that data back to the parent component.

You never want to mutate the props data given to the child component, however you CAN mutate a local state of the data, which could be an exact clone of the prop.

You can do this in many ways, I normally use a computed property as suggested in the Vue documentation: https://vuejs.org/v2/guide/components-props.html

in the computed return, just return the data coming in from the property.