Vuetify: [Bug Report] v-select onchange event returns previously selected value instead of current

[ChoChik]

Versions and Environment

Vuetify: 1.4.1
Last working version: 1.4.0
Vue: 2.5.21
Browsers: Chromium 71.0.3578.80
OS: Ubuntu undefined

Steps to reproduce

<template>
<v-select
      v-model="value"
      :items="items"
      @change="printValue()"
    ></v-select>
</template>

<script>
  export default {
    data: () => ({
      value: null,
      items: ['Foo', 'Bar', 'Fizz', 'Buzz']
    }),
    methods: {
      printValue() {
        console.log(this.value);
      }
    }
  }
</script>

Expected Behavior

When I selected Foo, it should console.log 'Foo',
And When I selected Bar, it should console.log 'Bar'.

Actual Behavior

When I selected Foo, it actually console.log 'null',
And When I selected Bar, it actually console.log 'Foo'.

Reproduction Link

https://codesandbox.io/s/m4n65nxvmx

[johnleider]

A better reproduction of your issue https://codepen.io/johnjleider/pen/JwwMoB

[ChoChik]

@johnleider thanks, man. It's my first time to use sandbox app.

[mascit13]

We also figured out, that the change event returns the previously selected instead of the current selected.

[KaelWD]

Not a bug.

@change="printValue"

methods: {
  printValue(val) {
    alert(val)
  }
}

or

- @change="printValue"

watch: {
  value (val) {
    alert(val)
  }
}

[mascit13]

Ah! We also made this mistake of accessing the binded property in change function. Here is a sandbox that shows the different values. nextTick() can help, but i think better way is to use the functions parameter.
https://codesandbox.io/s/vvjr2nylj0
thank KaelWD ;-)

[ChoChik]

@mascit13 thanks

[KaelWD]

This does actually seem to be a regression, caused by #6054 changing the event order. You should still be using the event value instead, but maybe this needs to be fixed to avoid breaking existing applications that're using poor practises.

[CarstenRuecker]

Just just stumbled upon this change in behaviour in 1.4 too. I fail to see why a variable bound to a v-model should be updated _after_ the change event is fired, because that's exactly the thing that changed. Best regards from layer 8 :P

https://codepen.io/logic7/pen/gqPwPB?editors=1111