Parsing and adding URL parameters with Javascript

The Problem

I need to add new parameter to a URL with parameters listed in it. I can just add it via string but I also need to check the value of one of the parameters in the URL. So, I have to get all the parameters attached, do some value checking on them, add new parameter, generate new URL with parameter added.

The Important Bits

This is the method that I use to extract parameters from URL and turned them into array.

function getURLParameters(url){

    var result = {};
    var searchIndex = url.indexOf("?");
    if (searchIndex == -1 ) return result;
    var sPageURL = url.substring(searchIndex +1);
    var sURLVariables = sPageURL.split('&');
    for (var i = 0; i < sURLVariables.length; i++)
    {       
        var sParameterName = sURLVariables[i].split('=');      
        result[sParameterName[0]] = sParameterName[1];
    }
    return result;
}

And here’s how I use it to process my URL

var url = document.createElement('a');
url.href = currentUrl;
var params = getURLParameters(currentUrl);

//do some checking
if(params["isParam"]) 
	//add new param
	params["newParam"] = "someValue";

var newUrl = url.origin + url.pathname + "?" + $.param(params);

Published: July 27 2015

category:
javascript 4