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e8a57cb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 | import { slice } from './util';
import options from './options';
import { NULL, UNDEFINED } from './constants';
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!
/** @type {import('./internal').VNode} */
const vnode = {
type,
props,
key,
ref,
_children: NULL,
_parent: NULL,
_depth: 0,
_dom: NULL,
_component: NULL,
constructor: UNDEFINED,
_original: original == NULL ? ++vnodeId : original,
_index: -1,
_flags: 0
};
// 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 VNode}
*/
export const isValidElement = vnode =>
vnode != NULL && vnode.constructor === UNDEFINED;
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