Slots Unification

breaking

Overview

This change unifies normal and scoped slots in 3.x.

Here is a quick summary of what has changed:

• this.$slots now exposes slots as functions
• BREAKING: this.$scopedSlots is removed

For more information, read on!

2.x Syntax

When using the render function, i.e., h, 2.x used to define the slot data property on the content nodes.

// 2.x Syntax
h(LayoutComponent, [
  h('div', { slot: 'header' }, this.header),
  h('div', { slot: 'content' }, this.content)
])

In addition, when referencing scoped slots, they could be referenced using the following syntax:

// 2.x Syntax
this.$scopedSlots.header

3.x Syntax

In 3.x, slots are defined as children of the current node as an object:

// 3.x Syntax
h(LayoutComponent, {}, {
  header: () => h('div', this.header),
  content: () => h('div', this.content)
})

And when you need to reference scoped slots programmatically, they are now unified into the $slots option.

// 2.x Syntax
this.$scopedSlots.header

// 3.x Syntax
this.$slots.header()

Migration Strategy

A majority of the change has already been shipped in 2.6. As a result, the migration can happen in one step:

1. Replace all this.$scopedSlots occurrences with this.$slots in 3.x.
2. Replace all occurrences of this.$slots.mySlot with this.$slots.mySlot()

Migration build flag: INSTANCE_SCOPED_SLOTS