wire and/or cola function to allow an arbitrary expression to be evaluated

cola.transform.expression.js

/** MIT License (c) copyright B Cavalier & J Hann */

(function (define, globalEval) {
define(function () {
"use strict";

	/**
	 * Creates a function that can be used to evaluate arbitrary expressions
	 * on a data item.
	 * @param options {Object}
	 * @returns {Function} function (value, item) {}
	 * @description
	 */
	return function createExpressionTransform (options) {
		return function expressionTransform (value, item) {
			try {
				return globalEval.call(options.expression, value, item);
			}
			catch (ex) {
				return ex.message;
			}
		}
	};

});
}(
	typeof define == 'function'
		? define
		: function (factory) { module.exports = factory(); },
	function (value, item) {
		// the only variables in scope are value, item, and any globals.
		// we have to cast to string because of "oddities" between
		// `eval` and `this`.
		return eval('' + this);
	}
));