mithril-vndb/docs/fragment.md

fragment(html)

• API
• How it works

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API

Generates a trusted HTML vnode

vnode = m.fragment(attrs, children)

Argument	Type	Required	Description
attrs	Object	Yes	A map of attributes
children	Array<Vnode>	Yes	A list of vnodes
returns	Vnode		A fragment vnode

How to read signatures

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How it works

m.fragment() creates a fragment vnode with attributes. It is meant for advanced use cases involving keys or lifecyle methods.

Normally you can use simple arrays instead to denote a list of child nodes or a range of nodes within a node list:

var groupVisible = true

m("ul", [
	m("li", "child 1"),
	m("li", "child 2"),
	groupVisible ? [
		m("li", "child 3"),
		m("li", "child 4"),
	] : null
])

There are a few benefits that come from using m.fragment instead of handwriting a vnode object structure: m.fragment creates monomorphic objects, which have better performance characteristics than creating objects dynamically. In addition, using m.fragment makes your intentions clear, and it makes it less likely that you'll mistakenly set attributes on the vnode object rather than on the attrs object.