Change Single Variable Value in Querystring

Change single variable value in querystring

Use

• parse_url() to extract the query string from the URL

• parse_str() to split the query string into an array

• array_merge() to add a new array "b" => 5

• http_build_query() to re-build a query string

• The remaining parts from the first step (protocol, host, path...) to re-build the full URL or - if you have the HTTP pecl extension - a http_build_url() with HTTP_URL_JOIN_QUERY will alleviate much of the work.

How can I add or update a query string parameter?

I wrote the following function which accomplishes what I want to achieve:

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

Is it possible to change the query string value

does it means that assigning values to the query string only at the time of redirection

Yes. The query string comes from the request the browser makes. You can't change a request that is being processed. You'll have to redirect using the new query string values.

Adding/Modify query string / GET variables in a url with javascript

No need to use jQuery on this one. Regular Expressions and string functions are sufficient. See my commented code below:

function addParameter(url, param, value) {
    // Using a positive lookahead (?=\=) to find the
    // given parameter, preceded by a ? or &, and followed
    // by a = with a value after than (using a non-greedy selector)
    // and then followed by a & or the end of the string
    var val = new RegExp('(\\?|\\&)' + param + '=.*?(?=(&|$))'),
        parts = url.toString().split('#'),
        url = parts[0],
        hash = parts[1]
        qstring = /\?.+$/,
        newURL = url;

    // Check if the parameter exists
    if (val.test(url))
    {
        // if it does, replace it, using the captured group
        // to determine & or ? at the beginning
        newURL = url.replace(val, '$1' + param + '=' + value);
    }
    else if (qstring.test(url))
    {
        // otherwise, if there is a query string at all
        // add the param to the end of it
        newURL = url + '&' + param + '=' + value;
    }
    else
    {
        // if there's no query string, add one
        newURL = url + '?' + param + '=' + value;
    }

    if (hash)
    {
        newURL += '#' + hash;
    }

    return newURL;
}

And here is the Fiddle

Update:

The code now handles the case where there is a hash on the URL.

Edit

Missed a case! The code now checks to see if there is a query string at all.

How can I change correctly the parameters in the query string for a URL after the event handler onclick?

Try this -

<script>
    function updateParams(abba){
        if(abba.href.search('quantity-0') > -1) {
            var a = abba.href.replace('quantity-0', 'add-0');
            abba.setAttribute('href', a);
        }
        else {
            var a = abba.href.replace('add-0','quantity-0');
            abba.setAttribute('href',a);
        }
    }
</script>

Hope this helps. Thanks!

Will Query String value change if multiple users access same page?

Based on your particular case above, the query string values between user1 and user2 will be totally independent. That means the first file uploaded by user1 will be saved to /txt folder and the second file uploaded by user2 will be saved to /img folder.

However, if both user1 and user2 upload files with the exact same name let's say abc.txt, then the first file from user1 will be overwritten by user2. You need to check the existence of the uploaded file name in page1 to avoid that. I would suggest renaming the uploaded file name by adding some incrementing number. For example, if user1 just uploaded abc.txt in page1, then when user2 also uploads abc.txt a bit later, change the file name to abc-1.txt, or to abc-2.txt if abc-1.txt also exists and so on. Hope that helps.

Search and replace specific query string parameter value in javascript

a_href = a_href.replace(/(test_ref=)[^\&]+/, '$1' + updated_test_ref);

Updating existing URL querystring values with jQuery

Get query string values this way and use $.param to rebuild query string

UPDATE:

This is an example, also check fiddle:

  function getQueryVariable(url, variable) {    var query = url.substring(1);     var vars = query.split('&');     for (var i=0; i<vars.length; i++) {          var pair = vars[i].split('=');          if (pair[0] == variable) {            return pair[1];          }     }
     return false;  }
  var url = 'http://www.example.com/hello.png?w=100&h=100&bg=white';         var w = getQueryVariable(url, 'w');  var h = getQueryVariable(url, 'h');  var bg = getQueryVariable(url, 'bg');
  // http://www.example.com/hello.png?w=200&h=200&bg=white  var params = { 'w':200, 'h':200, 'bg':bg };  var new_url = 'http://www.example.com/hello.png?' + jQuery.param(params);

unset($_GET['edit']); // delete edit parameter;
$_GET['pagenum'] = 5; // change page number
$qs = http_build_query($_GET);

... output link here.