Durandal - Type cast queryString parameters

By default, Durandal’s router.parseQueryString method will simply provide all query parameters as strings, which isn’t ideal if you’re working with data heavily.

We can work around this by overwriting and enhancing the parseQueryString method, type casting variables into their correct types.

/**
AMD module, **to be included before the rest of your durandal app**, that enhances
the native `router.parseQueryString` method, providing query parameters in their
correct primitive type, rather than always as strings.

@module Durandal.Router.Addons 
**/
define('plugins/router', function(router) {
    /**
    Parses a query string into an object, attempting to parse each query string param
    into a proper type
    
    @method parseQueryString
    @for Durandal.Router
    @param {String} queryString The query string to parse.
    @return {Object} An object keyed according to the query string parameters.
    **/
    var _parseQueryString = router.parseQueryString;
    router.parseQueryString = function () {
        var queryObject = _parseQueryString.apply(this, _.rest(arguments)),
            val, key;
    
        for(key in queryObject) {
            val = queryObject[key];
    
            // Float
            if (/^[+-]?[0-9]+\.[0-9]*$/.test(val)) {
                val = parseFloat(val);
            }
    
            // Integer
            else if (/^[+-]?[0-9]+$/.test(val)) {// simple int regex
                val = parseInt(val, 10);
            }
    
            // Booleans
            val = (!val && val !== 0) ? true : val;
            (val === 'true') && (val = true);
            (val === 'false') && (val = false);
    
            // Couldn't convert it, use the original value!
            if (val !== false && val !== true && !_.isNumber(val)) {
                val = val;
            }
    
            // Set the new value
            queryObject[key] = val;
        }
    
        return queryObject;
    };
});

This is useful for primitive data types, but as usual YMMV depending on the type of data you’re attempting to pass through!