如何将参数传递给url

Question

I'm trying to pass parameters to a URL and get them into a controller function: in an anchor onclick I passed the value to a javascript function.

This is the onclick anchor:

<a href="" onclick="change_lang('<?=base_url()?>home/change_lang','en')">English</a>

and this is the javascript function:

function change_lang(page,str)
{
  var url=page;
  var params='?lang='+str;

  makerequest_sp(url, params);
}

and this is the controller function:

public function change_lang()
{
  $lang=$this->input->Get('lang');

  if(!isset($lang))
  {
    $this->session->set_userdata('lang',"en"); 
  }
  else
  {
    $this->session->set_userdata('lang',$lang); 
  }

  redirect(base_url());
}

and this makerequest_sp function:

  function makerequest_sp(serverPage, params, objID)
{ 
    var xmlhttp_sp = getXMLHttp();
    //set url
    var url = serverPage;

    //set xml method to POST
    xmlhttp_sp.open("POST", url, true);
    //Send the proper header information along with the request
    xmlhttp_sp.setRequestHeader("Content-type", "application/x-www-form-urlencoded; charset=UTF-8");
    xmlhttp_sp.setRequestHeader("Content-length", params.length);
    xmlhttp_sp.setRequestHeader("Connection", "close");

    xmlhttp_sp.onreadystatechange = function() {//Call a function when the state changes.

        if(xmlhttp_sp.readyState == 4 && xmlhttp_sp.status == 200) {
            document.getElementById(objID).innerHTML = xmlhttp_sp.responseText;
        }
    }
    //send parameters
    xmlhttp_sp.send(params);    

}

But I cant access to passed parameters.

Answer 1

You're doing an AJAX request. I'm guessing you're wondering why the redirect doesn't make the browser redirect?

This is because the AJAX request is getting the redirect, not the page.

Instead of sending a redirect header you can pass back the URL the page should redirect to, or in case you know the URL already you can just redirect right away:

makerequest_sp(/* .. */).done(function () {
    document.location.href = url;
});

// using Promise assumption for ajax request