Javascript url redirection: Is there an issue with this code?

Question

Perhaps you can spot something I cannot:

This is my code

if(jQuery.urlParam('returnview')) {     
    var ret = jQuery.urlParam('returnview');
    var iid = jQuery.urlParam('iid'); 
    window.location = 'index.php?option=mycomponent&view='+ret+'&Itemid='+iid+'&lang=en';
} else  if(!jQuery.urlParam('returnview')){
  window.location = 'index.php?option=mycomponent&view=myview&Itemid=380&lang=en&sent=1'; 
} else {
  alert('something is dodge');
}

and this is the function:

jQuery.urlParam = function(name){
   var results = new RegExp('[\\?&amp;]' + name + '=([^&amp;#]*)').exec(window.location.href);
   return results[1] || 0;
}

Now, if there is a 'returnview' defined in my 'from' URL, it works fine. However, if there is no returnview defined, it should go to the second case or even if that fails, throw an alert.

Can anyone see anything obvious I am doing wrong here?

Thanks

Jacques

The `else if` should be an `else`. That third case can never happen. A boolean expression is either true or false. What's the problem you're noticing? — nbrooks, Mar 19 '13 at 09:55
Do you use firebug? If yes, then console.debug('index.php?option=mycomponent&view='+ret+'&Itemid='+iid+'&lang=en') just before first window.location and paste what it drops. — ex3v, Mar 19 '13 at 09:58

Lewis · Accepted Answer · 2013-03-19T10:20:59.560

Your third conditional will never get hit, because you're testing for true / false so lets remove that, leaving you with:

if(jQuery.urlParam('returnview')) {     
    var ret = jQuery.urlParam('returnview');
    var iid = jQuery.urlParam('iid'); 
    window.location = 'index.php?option=mycomponent&view='+ret+'&Itemid='+iid+'&lang=en';
} else{
  window.location = 'index.php?option=mycomponent&view=myview&Itemid=380&lang=en&sent=1'; 
}

Then lets move the vars outside of the ifs and check for false specifically (in case the value returned is equal to false, this needs an update to your original function which we do below):

var ret = jQuery.urlParam('returnview');
var iid;

if(ret === false) {     
   window.location = 'index.php?option=mycomponent&view=myview&Itemid=380&lang=en&sent=1'; 
} else{
  iid = jQuery.urlParam('iid'); 
  window.location = 'index.php?option=mycomponent&view='+ret+'&Itemid='+iid+'&lang=en';  
}

...and finally let's fix your original function:

jQuery.urlParam = function(name){
   var results = new RegExp('[\\?&amp;]' + name + '=([^&amp;#]*)').exec(window.location.href);
   return (results && results[0] ? results[0] : false);
}

I haven't tested it but I think that should fix it

`jQuery.urlParam = function(name){ var results = new RegExp('[\\?&]' + name + '=([^&#]*)').exec(window.location.href); return (results && results[0] ? results[0] : false); }` — imclickingmaniac, Mar 19 '13 at 10:08
this function works cool. Just small correct: `(results && results[0]) ? results[0] : 0;` on the end. Oh, and enable the console in firebug. It looks like you don't have it switched on :) — imclickingmaniac, Mar 19 '13 at 10:10
Thanks imclickingmaniac ... was rushing this through in SO :) — Lewis, Mar 19 '13 at 10:13
Thanks @Lewis and imclickingmaniac - the combination worked. Now redirecting correctly. — Jacques, Mar 19 '13 at 10:40

score 1 · Answer 2 · edited May 23 '17 at 12:28

1

check what is under jQuery.urlParam('returnview') im pretty sure that if value is not set you will get undefined.

Try jQuery.urlParam('returnview') === undefined

Also check out this post: Get escaped URL parameter

edited May 23 '17 at 12:28

Community

1
1

answered Mar 19 '13 at 09:55

imclickingmaniac

1,467
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28

It can't return `undefined`: the final line `return results[1] || 0;` returns `0` if `results[1]` is `undefined`. – nbrooks Mar 19 '13 at 10:03
Yes, my mistake. He posted the function that should return 0 but it will not. – imclickingmaniac Mar 19 '13 at 10:06

nbrooks · Answer 3 · 2013-03-19T10:37:18.757

Simply set the url parameters conditionally based on whether your function returns a truthy value:

var ret = jQuery.urlParam('returnview');
var iid = jQuery.urlParam('iid');

var view = ret || "myview";
var id = iid || "380";

window.location = 'index.php?option=mycomponent&view='+
                   view + '&Itemid=' + id + '&lang=en';

And for your urlParam function, you need to make sure you're only capturing the parameter itself, not the entire "&abc=xyz" segment. You just add parentheses around the desired portion to capture that, then take the second match (the first index). Before dereferencing the match array, check that it isn't null:

jQuery.urlParam = function(name){
    var re = RegExp('[\\?&amp;]' + name + '=([^&amp;#]*)');
    var results = window.location.href.match(re);
    return results ? results[1] : null;
}

Javascript url redirection: Is there an issue with this code?

3 Answers3