helpers.js

var moment = require('moment');
var queryBuilder = require('./queryBuilder.js').bind(null, 'https://someurl.com');

module.exports = helpers = {};

/* delete all key/value pairs on obj that are equal to the provided val */
helpers.deleteAll = function(obj, val) {
	for (var key in obj)
		if ((typeof obj[key] === 'string' ? obj[key].trim() : obj[key]) === val)
			delete obj[key];
	return obj;
};

/* delete all key/value pairs on target that are not in reference */
helpers.matchReference = function(target, reference) {
	var stripped = {};
	for (var key in target)
		if (key in reference)
			stripped[key] = target[key];
	return stripped;
};

/* return an anchor tag of the passed moment() date */
helpers.getPrettyDate = function(date) {
	var time = moment(date).calendar().split(' ');
	function getAnchor(s) { return '<a href="' + queryBuilder({ date_added : moment(date).format('MM-DD-YYYY') }).toString() + '">' + s + '</a>'; }
	if (time.length === 5) {
		return getAnchor(time.slice(0, 2).join(' ')) + ' ' + time.slice(2, time.length).join(' ');
	} else if (time.length === 4) {
		return getAnchor(time[0]) + ' ' + time.slice(1, time.length).join(' ');
	} else {
		return getAnchor(time);
	}
};

/* remove the time specification from moment.js' calendar() method */
helpers.calendarDate = function(date) {
	var time = moment(date).calendar().split(' ');
	if (time.length === 1) {
		return time.join(' ');
	} else if (time.length === 4) {
		return time[0];
	} else {
		return time.slice(0, 2).join(' ');
	}
};

/* convert any valid web address into a standardized, protocol-specific URL format */
helpers.formatUrl = function(url) {
	var remove = ['https://', 'http://', 'www.'];
	remove.forEach(function(s) { url = url.replace(s, ''); });
	return 'https://www.' + url;
};

/* determines whether it is appropriate to display form history given a redirection key */
helpers.getPreservedData = function(req, key) {
	if (req.session.preserved &&
		req.session.preserved[key] &&
		req.session.lastVisited === '/' + key) {
		return req.session.preserved[key];
	} else {
		if (req.session.preserved)
			delete req.session.preserved[key];
		return null;
	}
};

/* preserves form data (from req.body) but stores a custom, supplied error on the session object */
helpers.preserveAndRedirect = function(req, res, id, error) {
	req.session.error = error;
	req.session.preserved = req.session.preserved || {};
	req.session.preserved[id] = req.body;
	res.redirect(req.headers.referer.split('.com')[1]);
};

/* mixin-like function for adding all passed objects' key/value pairs onto a blank object and returning that object */
helpers.augment = function() {
	var objs = Array.prototype.slice.call(arguments);
	var result = {};
	objs.forEach(function(obj) {
		for (var key in obj)
			result[key] = obj[key];
	});
	return result;
};

/* convert a string into a proper title casing */
helpers.toProperCase = function(s) {
	return s.split(' ').map(function(word) {
		return word[0].toUpperCase() + word.slice(1).toLowerCase()
	}).join(' ');
};

/* convert an underscore_styled string to camelCase */
helpers._ToCamel = function(s) {
	var result = '';
	s.toLowerCase().split('_').forEach(function(term, idx) {
		result += ((idx === 0 ? term[0] : term[0].toUpperCase()) + term.slice(1));
	});
	return result;
};

/* apply an object of functions to a data object and add those key/value pairs to a new object and return */
helpers.reduceFnObj = function(fnObj, dataObj) {
	var o = {};
	for (var key in fnObj)
		o[key] = fnObj[key](dataObj);
	return o;
};

/* convert an object with underscore_styled keys to one with camelCase */
helpers._ObjToCamel = function(obj) {
	var result = {};
	for (var key in obj)
		result[helpers._ToCamel(key)] = obj[key];
	return result;
};