Files
react/React/hasArrayNature.js
T
2013-06-28 14:30:47 -07:00

53 lines
1.6 KiB
JavaScript

/**
* Copyright 2013 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @providesModule hasArrayNature
*/
/**
* Perform a heuristic test to determine if an object is "array-like".
*
* A monk asked Joshu, a Zen master, "Has a dog Buddha nature?"
* Joshu replied: "Mu."
*
* This function determines if its argument has "array nature": it returns
* true if the argument is an actual array, an `arguments' object, or an
* HTMLCollection (e.g. node.childNodes or node.getElementsByTagName()).
*
* @param obj An object to test.
* @return bool True if the object is array-like.
*/
function hasArrayNature(obj) {
return (
// not null/false
!!obj &&
// arrays are objects, NodeLists are functions in Safari
(typeof obj == 'object' || typeof obj == 'function') &&
// quacks like an array
('length' in obj) &&
// not window
!('setInterval' in obj) &&
(
// a real array
(Object.prototype.toString.call(obj) === "[object Array]" ||
// arguments
('callee' in obj) || // HTMLCollection/NodeList
'item' in obj)
)
);
}
module.exports = hasArrayNature;