ion-slide slideWillChange has already incremented the activeIndex

[ionitron-bot]

Original issue by @johanlantz on 2018-08-02T07:24:38Z

Bug Report

Ionic Info

cli packages: (/Users/yc00025/.nvm/versions/node/v8.7.0/lib/node_modules)

    @ionic/cli-utils  : 1.19.2
    ionic (Ionic CLI) : 3.20.0

local packages:

    @ionic/app-scripts : 3.1.11
    Ionic Framework    : ionic-angular 3.9.2

System:

    Node : v8.7.0
    npm  : 5.4.2
    OS   : macOS High Sierra

Misc:

    backend : pro

Describe the Bug
I have an ion-slides setup like this:

<ion-slides (ionSlideDidChange)="slideChanged()" (ionSlideWillChange)="slideWillChange()">

slideWillChange() {
   console.log(this.slides.getActiveIndex());
}

slideChanged($event) {
  console.log(this.slides.getActiveIndex());
}

Current Behavior
Both functions output the same activeIndex, i.e. the one we have already moved to.

Expected Behavior
imho, I would expect the slideWillChange() function to have activeIndex as the slide where we are before the transition and the slideChanged() function to output the activeIndex of the new slide once the transition is completed.