How can I add or update a query string parameter?

Question

With javascript how can I add a query string parameter to the url if not present or if it present, update the current value? I am using jquery for my client side development

Answer 1

Use this function to add, remove and modify query string parameter from URL based on jquery

/**
@param String url
@param object param {key: value} query parameter
*/
function modifyURLQuery(url, param){
    var value = {};

    var query = String(url).split('?');

    if (query[1]) {
        var part = query[1].split('&');

        for (i = 0; i < part.length; i++) {
            var data = part[i].split('=');

            if (data[0] && data[1]) {
                value[data[0]] = data[1];
            }
        }
    }

    value = $.extend(value, param);

    // Remove empty value
    for (i in value){
        if(!value[i]){
            delete value[i];
        }
    }

    // Return url with modified parameter
    if(value){
        return query[0] + '?' + $.param(value);
    } else {
        return query[0];
    }
}

Add new and modify existing parameter to url

var new_url = modifyURLQuery("http://google.com?foo=34", {foo: 50, bar: 45});
// Result: http://google.com?foo=50&bar=45

Remove existing

var new_url = modifyURLQuery("http://google.com?foo=50&bar=45", {bar: null});
// Result: http://google.com?foo=50

Answer 2

This should serve the purpose:

function updateQueryString(url, key, value) {
    var arr =  url.split("#");
    var url = arr[0];
    var fragmentId = arr[1];
    var updatedQS = "";
    if (url.indexOf("?") == -1) {
        updatedQS = encodeURIComponent(key) + "=" + encodeURIComponent(value);
    }
    else {
        updatedQS = addOrModifyQS(url.substring(url.indexOf("?") + 1), key, value); 
    }
    url = url.substring(0, url.indexOf("?")) + "?" + updatedQS;
    if (typeof fragmentId !== 'undefined') {
        url = url + "#" + fragmentId;
    }
    return url;
}

function addOrModifyQS(queryStrings, key, value) {
    var oldQueryStrings = queryStrings.split("&");
    var newQueryStrings = new Array();
    var isNewKey = true;
    for (var i in oldQueryStrings) {
        var currItem = oldQueryStrings[i];
        var searchKey = key + "=";
        if (currItem.indexOf(searchKey) != -1) {
            currItem = encodeURIComponent(key) + "=" + encodeURIComponent(value);
            isNewKey = false;
        }
        newQueryStrings.push(currItem);
    }
    if (isNewKey) {
        newQueryStrings.push(encodeURIComponent(key) + "=" + encodeURIComponent(value));
    }
    return newQueryStrings.join("&");
}   

Answer 3

If it's not set or want to update with a new value you can use:

window.location.search = 'param=value'; // or param=new_value

This is in simple Javascript, by the way.

EDIT

You may want to try using the jquery query-object plugin

window.location.search = jQuery.query.set("param", 5);

Answer 4

if you want to set multiple parameters at once:

function updateQueryStringParameters(uri, params) {
    for(key in params){
      var value = params[key],
          re = new RegExp("([?&])" + key + "=.*?(&|$)", "i"),
          separator = uri.indexOf('?') !== -1 ? "&" : "?";
      if (uri.match(re)) {
        uri = uri.replace(re, '$1' + key + "=" + value + '$2');
      }
      else {
        uri = uri + separator + key + "=" + value;
      }
    }
    return uri;
}

same function as @amateur's

if jslint gives you an error add this after the for loop

if(params.hasOwnProperty(key))

Answer 5

window.location.search is read/write.

However - modifying the query string will redirect the page you're on and cause a refresh from the server.

If what you're attempting to do is maintain client side state (and potentially make it bookmark-able), you'll want to modify the URL hash instead of the query string, which keeps you on the same page (window.location.hash is read/write). This is how web sites like twitter.com do this.

You'll also want the back button to work, you'll have to bind javascript events to the hash change event, a good plugin for that is http://benalman.com/projects/jquery-hashchange-plugin/

Answer 6

I know this is quite old but i want to fires my working version in here.

function addOrUpdateUrlParam(uri, paramKey, paramVal) {
  var re = new RegExp("([?&])" + paramKey + "=[^&#]*", "i");
  if (re.test(uri)) {
    uri = uri.replace(re, '$1' + paramKey + "=" + paramVal);
  } else {
    var separator = /\?/.test(uri) ? "&" : "?";
    uri = uri + separator + paramKey + "=" + paramVal;
  }
  return uri;
}

jQuery(document).ready(function($) {
  $('#paramKey,#paramValue').on('change', function() {
    if ($('#paramKey').val() != "" && $('#paramValue').val() != "") {
      $('#uri').val(addOrUpdateUrlParam($('#uri').val(), $('#paramKey').val(), $('#paramValue').val()));
    }
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input style="width:100%" type="text" id="uri" value="http://www.example.com/text.php">
<label style="display:block;">paramKey
  <input type="text" id="paramKey">
</label>
<label style="display:block;">paramValue
  <input type="text" id="paramValue">
</label>

NOTE This is a modified version of @elreimundo