Internet-programming_PIbd-2.../Library/node_modules/lodash/result.js

57 lines
1.4 KiB
JavaScript

var castPath = require('./_castPath'),
isFunction = require('./isFunction'),
toKey = require('./_toKey');
/**
* This method is like `_.get` except that if the resolved value is a
* function it's invoked with the `this` binding of its parent object and
* its result is returned.
*
* @static
* @since 0.1.0
* @memberOf _
* @category Object
* @param {Object} object The object to query.
* @param {Array|string} path The path of the property to resolve.
* @param {*} [defaultValue] The value returned for `undefined` resolved values.
* @returns {*} Returns the resolved value.
* @example
*
* var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };
*
* _.result(object, 'a[0].b.c1');
* // => 3
*
* _.result(object, 'a[0].b.c2');
* // => 4
*
* _.result(object, 'a[0].b.c3', 'default');
* // => 'default'
*
* _.result(object, 'a[0].b.c3', _.constant('default'));
* // => 'default'
*/
function result(object, path, defaultValue) {
path = castPath(path, object);
var index = -1,
length = path.length;
// Ensure the loop is entered when path is empty.
if (!length) {
length = 1;
object = undefined;
}
while (++index < length) {
var value = object == null ? undefined : object[toKey(path[index])];
if (value === undefined) {
index = length;
value = defaultValue;
}
object = isFunction(value) ? value.call(object) : value;
}
return object;
}
module.exports = result;