eam-offline-app/doc/vue-select/guide/upgrading.md

index prop replaced with reduce

• v2.x provided the index {String} prop to return a single key from a selected object
• v3.x removes the index prop, replacing it with the reduce {Function} prop.

Using a function instead of a string provides a whole lot more flexibility, allowing for things like deeply nested values, and really cleaned up the code internally.

const options = [{country: 'Canada', code: 'CA'},];

<!-- v2: using index --->
<v-select :options="options" label="country" index="code"  />

<!-- v3: using reduce --->
<v-select :options="options" label="country" :reduce="country => country.code" />

View the full documentation for reduce.

Events instead of Callbacks

Three function callbacks have been removed in favor of using events.

• onChange
• onInput
• onSearch

While this is a breaking change, the change in your application should be as simple as swapping the prop you were using for an event.

onChange & onInput

In v2.x, Overwriting onChange in an application was more likely to break vue-select's internals and cause issues. The input event provides identical functionality and can be swapped out in your application.

<!-- version 2: -->
<v-select :on-change="doSomething" />

<!-- version 3: -->
<v-select @input="doSomething" />

Additionally, the change event has been removed. This event was redundant, input should be used instead.

<!-- version 2: -->
<v-select @change="doSomething" />

<!-- version 3: -->
<v-select @input="doSomething" />

onSearch

The onSearch prop was removed for the same reason as onChange and onInput. The search event has always provided the same parameters and can be used in it's place.

<!-- version 2: -->
<v-select :on-search="doSomeAjax" />

<!-- version 3: -->
<v-select @search="doSomeAjax" />

@search with null search string

The @search event is now fired anytime the search string changes. In v2.x, the component would first check if the search string was empty, and only emit the event if it had at least one character. This was a design mistake, as it should be the consumers decision if a search should be run on an empty string.

Separated CSS

CSS was removed from the JS bundle in favor of a separate CSS file to support SSR and easier customization.

  @import vSelect from 'vue-select`;
  @import 'vue-select/dist/vue-select.css';

New Class Selector Prefix

In order to avoid CSS collisions and allow for low specificity overrides of CSS, all classes have been renamed to include the vs__ prefix. The full list of renamed classes are listed below:

original	renamed
.open-indicator	.vs__open-indicator
.dropdown-toggle	.vs__dropdown-toggle
.dropdown-menu	.vs__dropdown-menu
.clear	.vs__clear
.selected-tag	.vs__selected
.no-options	.vs__no-options
.spinner	.vs__spinner
.close	.vs__deselect
.active	.vs__active

Internal State

The changes listed below are very unlikely to break your apps unless you've been hooking into vue-select internal values. #781 (thanks @owenconti!) introduced a number of optimizations to the way that the component handles internal state.

• value: the value prop is undefined by default. vue-select no longer maintains an internal mutableValue state when a value prop has been passed. When :value or v-model is not used, vue-select will maintain internal state using the _value property.
• mutableOptions has been removed in favor of an optionList computed property.

Misc

• fade transition renamed to vs__fade
• Removed a element that was serving as the click handler within dropdown options