Make v-model work with props

[backbone87]

What problem does this feature solve?

It would be nice, if v-model works when using a prop as its target. By allowing this, we would reduce error prone boilerplate code, when having "pass-through" input/model components.

A similar request was made in #8403 , however there is acutally no need to introduce a new modifier or anything.

The v-model logic would be modified in the following way:

• If the target of v-model is not a prop: Use the current behavior
• Else, the target of v-model is a prop:
  • If the prop is the model of this component (by looking at the components options.model.prop), emit an event of the type declared in options.model.event with the new value
  • Else, emit an event of type update:PROP_NAME with the new value

Similar logic can be done for the .sync modifier targeting props.

What does the proposed API look like?

No API changes needed

[yyx990803]

I don't think I understand what you are asking for. Please follow the RFC process to better describe your proposal.