2025-05-31 22:40:29 +02:00

99 lines
3.0 KiB
JavaScript

import { slice } from './util';
import options from './options';
let vnodeId = 0;
/**
* Create an virtual node (used for JSX)
* @param {import('./internal').VNode["type"]} type The node name or Component
* constructor for this virtual node
* @param {object | null | undefined} [props] The properties of the virtual node
* @param {Array<import('.').ComponentChildren>} [children] The children of the virtual node
* @returns {import('./internal').VNode}
*/
export function createElement(type, props, children) {
let normalizedProps = {},
key,
ref,
i;
for (i in props) {
if (i == 'key') key = props[i];
else if (i == 'ref') ref = props[i];
else normalizedProps[i] = props[i];
}
if (arguments.length > 2) {
normalizedProps.children =
arguments.length > 3 ? slice.call(arguments, 2) : children;
}
// If a Component VNode, check for and apply defaultProps
// Note: type may be undefined in development, must never error here.
if (typeof type == 'function' && type.defaultProps != null) {
for (i in type.defaultProps) {
if (normalizedProps[i] === undefined) {
normalizedProps[i] = type.defaultProps[i];
}
}
}
return createVNode(type, normalizedProps, key, ref, null);
}
/**
* Create a VNode (used internally by Preact)
* @param {import('./internal').VNode["type"]} type The node name or Component
* Constructor for this virtual node
* @param {object | string | number | null} props The properties of this virtual node.
* If this virtual node represents a text node, this is the text of the node (string or number).
* @param {string | number | null} key The key for this virtual node, used when
* diffing it against its children
* @param {import('./internal').VNode["ref"]} ref The ref property that will
* receive a reference to its created child
* @returns {import('./internal').VNode}
*/
export function createVNode(type, props, key, ref, original) {
// V8 seems to be better at detecting type shapes if the object is allocated from the same call site
// Do not inline into createElement and coerceToVNode!
const vnode = {
type,
props,
key,
ref,
_children: null,
_parent: null,
_depth: 0,
_dom: null,
// _nextDom must be initialized to undefined b/c it will eventually
// be set to dom.nextSibling which can return `null` and it is important
// to be able to distinguish between an uninitialized _nextDom and
// a _nextDom that has been set to `null`
_nextDom: undefined,
_component: null,
_hydrating: null,
constructor: undefined,
_original: original == null ? ++vnodeId : original
};
// Only invoke the vnode hook if this was *not* a direct copy:
if (original == null && options.vnode != null) options.vnode(vnode);
return vnode;
}
export function createRef() {
return { current: null };
}
export function Fragment(props) {
return props.children;
}
/**
* Check if a the argument is a valid Preact VNode.
* @param {*} vnode
* @returns {vnode is import('./internal').VNode}
*/
export const isValidElement = vnode =>
vnode != null && vnode.constructor === undefined;