ziploop-util

Utility functions created by the Ziploop engineering team

throttleForEach

A throttled forEach function, allowing the user to specify how quickly to iterate over an array. It was created to help with API requests where a fixed number of items need to be called at a fixed rate to avoid exceeding limits, without the complexity of a pool of requests that grows and shrinks over time, or where thinking about limits in terms of workers is not helpful.

Arguments: throttleForEach(array, waitTime, iterator)

The array is passed to the function so it can work with array-like objects (like Mongo cursors) without extending the Array prototype. Wait times are given in milliseconds. The iterator is passed two arguments: an array item and its index.

Example

var array = ["Jake", "Paul", "Autumn", "Brendon", "John Boy"];
throttleForEach(array, 1000, function(name, i){
	console.log(name + " is at index " + i);
});

validParams

Checks an object against an array of valid/allowed properties, with an optional 'strict mode' to eliminate unallowed properties from the object. It was created to check req.body or req.query in Node/Express for a route's required parameters.

Arguments: validParams(objectToCheck, arrayOfParameters, strictMode)

The arrayOfParameters should contain strings of allowed property names. The strictMode boolean specifies whether to return all properties (false) or only those matching properties in the arrayOfParameters list (true).

Example

var testObj = {
	'one': 1,
	'two': 2,
	'three': 3
}
validParams(testObj, ['one', 'two'], false) // returns {one: 1, two: 2, three: 3}
validParams(testObj, ['one', 'two'], true) // returns {one: 1, two: 2}
validParams(testObj, ['one', 'two', 'cow'], false) // returns false
validParams(testObj, ['one', 'two', 'cow'], true) // returns false
validParams(testObj, ['one', 'two']) // returns {one: 1, two: 2, three: 3}