Redirection to a specific web page based on URL parameter using Javascript

Question

I have a simple .htm web page kept in different folders for handling different languages.

default.htm inside en folder ( en\\default.htm and de\\default.htm and so on)

I need to redirect to a specific web page based on the URL parameter ie if the user had

specified http://localhost/website/default.htm?lang=de , i need to redirect him to the

de\\default.htm file. ie a german web page.

had it been the ASPX pages i would have done away with the job easily with ResourceManager

and an appropriate .resx file using the Request.QueryString option provided by .NET

BCL. However since i'm using plain HTML page i do not have an expertise to write a client

side script like javascript to query for the URL parameters and redirect the user to the

required page.

Question :

Can anyone guide me how do i achieve the same using any form of client scripting to

achieve the redirection ?? And where do i invoke the script function ?

ie query the parameter for each post event.??

Thanks a ton

Answer 1

You can use javascript to get a list of params pretty easily with the following line.

var paramArray = window.location.search.substring(1).split("&")

This will build an array of the parameters of the query string. From there you just need to add logic to find the param you specified in your question and take the appropriate redirect using

window.location.href = 'some URL'; //causes the browser to refresh with the new URL

Example:

function getQueryStringArray(){
    var assoc=[]; 
    var items = window.location.search.substring(1).split('&'); 
    for(var j = 0; j < items.length; j++) { 
       var a = items[j].split('='); assoc[a[0]] = a[1]; 
    }
    return assoc;
}

//point at which you want to determine redirection
var qs = getQueryStringArray();
var url = '';
if (qs.lang !== 'undefined' && qs.lang) {
   switch (qs.lang) {
      case 'en':
         url = 'blah';
         break;
      case 'de': 
         url = 'meh';
         break;
   }
   window.location.href = url; //reroute
 }

Answer 2

See this on how to parse query string parameters using jQuery How can I get query string values in JavaScript?

Then you can redirect to another page with window.location

Something like this

<script>
    $(document).ready(function(){
   var p = getParameterByName("lang");
   var rootUrl = "yourRootUrl";
    var url = rootUrl + p + '/default.htm';
   window.location = url;
});
</script>

No jQuery

<script>
     (function(){
          var p = getParameterByName("lang");
          var rootUrl = "yourRootUrl/";
          var url = rootUrl + p + '/default.htm';
          window.location = url;
     }());
</script>

Answer 3

The following should do it for you. Just wrap it in <script></script> tags.

// Locate "lang=...." in the url using regex;
var a = /[\?&]lang=([^\/&#\?]+)/i.exec(window.location.pathname);
// check if the regex matched
if (a) {
    // If so, redirect the user
    window.location.href = "http://localhost/website/" + a[1] + "/index.htm";
}

This will save you from having to loop through the url, but it does require a basic understanding of how regexp works.