[javascript] Add / Change parameter of URL and redirect to the new URL

If the &view-all parameter does NOT exist in the URL I need to add it to the end of the URL along with a value. If it DOES exist then I need to be able to just change the value without creating a new URL because it might, or might not, have other parameters before it.

I found this function but I can't get it to work: https://stackoverflow.com/a/10997390/837705

Here is the code I have using the function above (which I can't get to work): http://jsfiddle.net/Draven/tTPYL/4/

I know how to append the parameter and value already:

<div onclick="javascript: window.location.assign(window.location.href+='&view-all=Yes');">Blah Blah</div>

More Info:

If the URL is http://www.domain.com/index.php?action=my_action then the default "&view-all" value would be "Yes" so the URL they would be directed to when they click the button is http://www.domain.com/index.php?action=my_action&view-all=Yes.

If the URL is http://www.domain.com/index.php?action=my_action&view-all=Yes then when they click the button it would change to http://www.domain.com/index.php?action=my_action&view-all=No???

EDIT: Please give me examples. I don't know alot of JS, and I just can't think of a way to do it in PHP.

All the preivous solution doesn't take in account posibility of the substring in parameter. For example http://xyz?ca=1&a=2 wouldn't select parameter a but ca. Here is function which goes through parameters and checks them.

function setGetParameter(paramName, paramValue)
{
  var url = window.location.href;
  var hash = location.hash;
  url = url.replace(hash, '');
  if (url.indexOf("?") >= 0)
  {
    var params = url.substring(url.indexOf("?") + 1).split("&");
    var paramFound = false;
    params.forEach(function(param, index) {
      var p = param.split("=");
      if (p[0] == paramName) {
        params[index] = paramName + "=" + paramValue;
        paramFound = true;
      } 
    });
    if (!paramFound) params.push(paramName + "=" + paramValue);
    url = url.substring(0, url.indexOf("?")+1) + params.join("&");
  }
  else
    url += "?" + paramName + "=" + paramValue;
  window.location.href = url + hash;
}

i would suggest a little change to @Lajos's answer... in my particular situation i could potentially have a hash as part of the url, which will cause problems for parsing the parameter that we're inserting with this method after the redirect.

function setGetParameter(paramName, paramValue) {
    var url = window.location.href.replace(window.location.hash, '');
    if (url.indexOf(paramName + "=") >= 0) {
        var prefix = url.substring(0, url.indexOf(paramName));
        var suffix = url.substring(url.indexOf(paramName));
        suffix = suffix.substring(suffix.indexOf("=") + 1);
        suffix = (suffix.indexOf("&") >= 0) ? suffix.substring(suffix.indexOf("&")) : "";
        url = prefix + paramName + "=" + paramValue + suffix;
    }else {
        if (url.indexOf("?") < 0)
            url += "?" + paramName + "=" + paramValue;
        else
            url += "&" + paramName + "=" + paramValue;
    }
    url += window.location.hash;
    window.location.href = url;
}

I need help to adjust my script below or to find a script that could be used on my wordpress site to grab the url suffix parameters from a forward url, then to be added at the button click url for tracking the proper forward ads id.

REASON: parameters are used for advertisement tracking to find out from which ad the user has been forward, even if the user hops from optin page to the sales page by using button click.

Here the goal to reach: 1. An FB ad points to an optin page with tracking code: https://ownsite.com/optin-page/?tid=fbad1 2. At the optin-page there is a button with a setup URL to forward to the sales page, but if clicked then only the URL is forward, but the parameter "?tid=fbad1" is missing. 3. The auto-forward script below (which is working properly) can be used to change for button click forward, but has a limitation as it grab only "tid" parameters instead also utm parameters.

Therefore a script code shall be implemented to establish click buttons (also to style them or use images instead) and while clicking the button to forward to a different sales page with grabbing the suffix parameter form the current optin-page to forward then to sales-page https://ownsite.com/sales-page/?tid=fbad1 also including UTM parameters

Currently, I could have solved this by using an auto-redirect script, but A.) I do not want to use an autoredirect at this page. Better is an event click button used to let the user himself click to forward with the URL parameter included. B.) The tracking ID parameter in this script is limited to "?tid=..." instead I do also want to track the UTM code on button click also i.e. Grab from current page the paramater of URL https://www.optin-page.com/?tid=facebookad1?utm_campaign=blogpost then on button click grab parameters and add to button set URL https://www.sales-page.com/?tid=facebookad1?utm_campaign=blogpost

Please now find here the Code below in use for auto-redirect and grabbing the URL parameters. This code shall be changed now to be able to create a button with a click-event to be redirect then to the forward URL with parameter grabbing of current URL if the button is clicked (as stated above).

    <p><!-- Modify this according to your requirement - core script from https://gist.github.com/Joel-James/62d98e8cb3a1b6b05102 and suffix grabbing </p>
    <h3 style="text-align: center;"><span style="color: #ffffff; background-color: #039e00;">?Auto-redirecting after <span id="countdown">35</span> seconds?</span></h3>
    <p><!-- JavaScript part --><br /><script type="text/javascript">

function findGetParameter(parameterName) {
    var result = null,
        tmp = [];
    location.search
        .substr(1)
        .split("&")
        .forEach(function (item) {
          tmp = item.split("=");
          if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
        });
    return result;
}


    // Total seconds to wait
    var seconds = 45;

    function countdown() {
        seconds = seconds - 1;
        if (seconds < 0) {
            // Chnage your redirection link here
var tid = findGetParameter('tid');
window.location = "https://www.2share.info/ql-cb2/" + '?tid='+tid;
        } else {
            // Update remaining seconds
            document.getElementById("countdown").innerHTML = seconds;
            // Count down using javascript
            window.setTimeout("countdown()", 1000);
        }
    }

    // Run countdown function
    countdown();

</script></p>

I think something like this would work, upgrading the @Marc code:

//view-all parameter does NOT exist  
$params = $_GET;  
if(!isset($_GET['view-all'])){  
  //Adding view-all parameter  
  $params['view-all'] = 'Yes';  
}  
else{  
  //view-all parameter does exist!  
  $params['view-all'] = ($params['view-all'] == 'Yes' ? 'No' : 'Yes');  
}
$new_url = $_SERVER['PHP_SELF'].'?'.http_build_query($params);

Some simple ideas to get you going:

In PHP you can do it like this:

if (!array_key_exists(explode('=', explode('&', $_GET))) {
  /* add the view-all bit here */
}

In javascript:

if(!location.search.match(/view\-all=/)) {
  location.href = location.href + '&view-all=Yes';
}

I had a similar situation where I wanted to replace a URL query parameter. However, I only had one param, and I could simply replace it:

window.location.search = '?filter=' + my_filter_value

The location.search property allows you to get or set the query portion of a URL.

To do it in PHP: You have a couple of parameters to view your page, lets say action and view-all. You will (probably) access these already with $action = $_GET['action'] or whatever, maybe setting a default value.

Then you decide depending on that if you want to swich a variable like $viewAll = $viewAll == 'Yes' ? 'No' : 'Yes'.

And in the end you just build the url with these values again like

$clickUrl = $_SERVER['PHP_SELF'] . '?action=' . $action . '&view-all=' . $viewAll;

And thats it.

So you depend on the page status and not the users url (because maybe you decide later that $viewAll is Yes as default or whatever).

Why parse the query string yourself when you can let the browser do it for you?

function changeQS(key, value) {
    let urlParams = new URLSearchParams(location.search.substr(1));
    urlParams.set(key, value);
    location.search = urlParams.toString();
}

This is my sample code for rebuild url query string with JS

//function get current parameters_x000D_
$.urlParam = function(name){_x000D_
    var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);_x000D_
    if (results==null){_x000D_
        return null;_x000D_
    }_x000D_
    else{_x000D_
        return results[1] || 0;_x000D_
    }_x000D_
};_x000D_
_x000D_
//build a new parameters_x000D_
var param1 = $.urlParam('param1');_x000D_
var param2 = $.urlParam('param2');_x000D_
_x000D_
//check and create an array to save parameters_x000D_
var params = {};_x000D_
    if (param1 != null) {_x000D_
        params['param1'] = param1;_x000D_
    }_x000D_
    if (order != null) {_x000D_
        params['param2'] = param2;_x000D_
    }_x000D_
_x000D_
//build a new url with new parameters using jQuery param_x000D_
window.location.href =  window.location.origin + window.location.pathname + '?' + $.param(params);

I used JQUERY param: http://api.jquery.com/jquery.param/ to create a new url with new parameters.

though i take the url from an input, it's easy adjustable to the real url.

var value = 0;

$('#check').click(function()
{
    var originalURL = $('#test').val();
    var exists = originalURL.indexOf('&view-all');

    if(exists === -1)
    {
        $('#test').val(originalURL + '&view-all=value' + value++);
    }
    else
    {
        $('#test').val(originalURL.substr(0, exists + 15) + value++);
    }
});

http://jsfiddle.net/8YPh9/31/

var updateQueryStringParameter = function (key, value) {

    var baseUrl = [location.protocol, '//', location.host, location.pathname].join(''),
        urlQueryString = document.location.search,
        newParam = key + '=' + value,
        params = '?' + newParam;

    // If the "search" string exists, then build params from it
    if (urlQueryString) {
        var updateRegex = new RegExp('([\?&])' + key + '[^&]*');
        var removeRegex = new RegExp('([\?&])' + key + '=[^&;]+[&;]?');

        if( typeof value == 'undefined' || value == null || value == '' ) { 
            params = urlQueryString.replace(removeRegex, "$1");
            params = params.replace( /[&;]$/, "" );

        } else if (urlQueryString.match(updateRegex) !== null) { 
            params = urlQueryString.replace(updateRegex, "$1" + newParam);

        } else {
            params = urlQueryString + '&' + newParam;
        }
    }

    // no parameter was set so we don't need the question mark
    params = params == '?' ? '' : params;

    window.history.replaceState({}, "", baseUrl + params);
};

Here's a way of accomplishing this. It takes the param name and param value, and an optional 'clear'. If you supply clear=true, it will remove all other params and just leave the newly added one - in other cases, it will either replace the original with the new, or add it if it's not present in the querystring.

This is modified from the original top answer as that one broke if it replaced anything but the last value. This will work for any value, and preserve the existing order.

function setGetParameter(paramName, paramValue, clear)
{
clear = typeof clear !== 'undefined' ? clear : false;
var url = window.location.href;
var queryString = location.search.substring(1); 
var newQueryString = "";
if (clear)
{
    newQueryString = paramName + "=" + paramValue;
}
else if (url.indexOf(paramName + "=") >= 0)
{
    var decode = function (s) { return decodeURIComponent(s.replace(/\+/g, " ")); };
    var keyValues = queryString.split('&'); 
    for(var i in keyValues) { 
        var key = keyValues[i].split('=');
        if (key.length > 1) {
            if(newQueryString.length > 0) {newQueryString += "&";}
            if(decode(key[0]) == paramName)
            {
                newQueryString += key[0] + "=" + encodeURIComponent(paramValue);;
            }
            else
            {
                newQueryString += key[0] + "=" + key[1];
            }
        }
    } 
}
else
{
    if (url.indexOf("?") < 0)
        newQueryString = "?" + paramName + "=" + paramValue;
    else
        newQueryString = queryString + "&" + paramName + "=" + paramValue;
}
window.location.href = window.location.href.split('?')[0] + "?" + newQueryString;
}