`__InsertElementBefore`

Introduction

Inserts an Element node into the specified parent node, before the reference node.

Syntax

__InsertElementBefore(parent: Element, child: Element, referenceNode: Element) : Element;

Parameters

Key	Description
parent	The parent node object.
child	The child node to be inserted into the parent node.
referenceNode	The reference node before which the child node needs to be inserted. If the reference node is null, the child node will be inserted at the end.

Return Value

Returns the inserted child node.

Example

The frontend framework can perform the insertion operation as follows.

// main-thread.js
let first = __CreateElement('view', 0, {});

let last = __CreateElement('view', 0, {});

let mid = __CreateElement('view', 0, {});

let parent = __CreateElement('view', 0, {});

__AppendElement(parent, first);
__AppendElement(parent, last);

__InsertElementBefore(parent, mid, last);

#__InsertElementBefore

#Introduction

#Syntax

#Parameters

#Return Value

#Example

`__InsertElementBefore`

Introduction

Syntax

Parameters

Return Value

Example