jsexpr/lib/mingo_ex.js

String and JSON expression interpolator and evaluator. Interpolates or evaluates a string against a json object, or transforms an object into another based on a json template

const
	mingo = require('mingo'),
	jsexpr = require('./expression')('$');

const EV_CACHE = {};
const EX_CACHE = {};

try {
	mingo.addOperators(mingo.OP_QUERY, function (_) {
		return {
			$starts(selector, value, args) {
				args = Array.isArray(args) ? args : [args];
				return (value || "").startsWith(args[0]);
			},
			$startsWith(selector, value, args) {
				args = Array.isArray(args) ? args : [args];
				return (value || "").startsWith(args[0]);
			},
			$ends(selector, value, args) {
				args = Array.isArray(args) ? args : [args];
				return (value || "").endsWith(args[0]);
			},
			$endsWith(selector, value, args) {
				args = Array.isArray(args) ? args : [args];
				return (value || "").endsWith(args[0]);
			},
			$contains(selector, value, args) {
				args = Array.isArray(args) ? args : [args];
				return (value || "").indexOf(args[0]) >= 0;
			}
		};
	});
	
	mingo.addOperators(mingo.OP_EXPRESSION, function (_) {
		return {
			$eval(selector, value, args) {
				if (!EV_CACHE[value]) {
					EV_CACHE[value] = jsexpr.eval(value);
				}
				return EV_CACHE[value](selector);
			},
			$expr(selector, value, args) {
				if (!EX_CACHE[value]) {
					EX_CACHE[value] = jsexpr.expr(value);
				}
				return EX_CACHE[value](selector);
			},
			$keyval(selector, value, args) {
				let val = _.computeValue(selector, value);
				return val.reduce((map, item) => {
					map[item[0]] = item[1] || "_";
					return map;
				}, {});
			},
			$trim(selector, value, args) {
				let chars = new Set((value.chars || '').split(''));
				let val = _.computeValue(selector, value.input).split('');
				while (chars.has(val[0])) val.shift();
				while (chars.has(val[val.length - 1])) val.pop();
				return val.join('');
			},
			$starts(selector, value, args) {
				let val = _.computeValue(selector, value[0]);
				return (val || "").startsWith(value[1]);
			},
			$startsWidth(selector, value, args) {
				let val = _.computeValue(selector, value[0]);
				return (val || "").startsWith(value[1]);
			},
			$ends(selector, value, args) {
				let val = _.computeValue(selector, value[0]);
				return (val || "").endsWith(value[1]);
			},
			$endsWith(selector, value, args) {
				let val = _.computeValue(selector, value[0]);
				return (val || "").endsWith(value[1]);
			},
			$contains(selector, value, args) {
				let val = _.computeValue(selector, value[0]);
				return (val || "").indexOf(value[1]) >= 0;
			}
		};
	});
}catch(err) {
	
}


module.exports = mingo;