39 lines
1.2 KiB
JavaScript
39 lines
1.2 KiB
JavaScript
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"use strict";
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var map_1 = require('./map');
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/**
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* Retrieves the value of a specified nested property from all elements in
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* the Observable sequence. If a property can't be resolved, it will return
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* `undefined` for that value.
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*
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* @param {...args} properties the nested properties to pluck
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* @returns {Observable} Returns a new Observable sequence of property values
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*/
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function pluck() {
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var properties = [];
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for (var _i = 0; _i < arguments.length; _i++) {
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properties[_i - 0] = arguments[_i];
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}
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var length = properties.length;
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if (length === 0) {
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throw new Error('List of properties cannot be empty.');
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}
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return map_1.map.call(this, plucker(properties, length));
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}
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exports.pluck = pluck;
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function plucker(props, length) {
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var mapper = function (x) {
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var currentProp = x;
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for (var i = 0; i < length; i++) {
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var p = currentProp[props[i]];
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if (typeof p !== 'undefined') {
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currentProp = p;
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}
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else {
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return undefined;
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}
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}
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return currentProp;
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};
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return mapper;
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}
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//# sourceMappingURL=pluck.js.map
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