How to encode a query string so that it is the value of another query string in javascript?

Question

I have a javascript function which passes as a query string value another query string.

In other words, I want the query string to be:

http://www.somesite.com/?somequery=%3fkey%3dvalue1%2520%26%2520key2%3value3

However, if I redirect like this:

var url = 'http://www.somesite.com/?somequery=';
url += escape('?key=value1&key2=value2');
window.location = url;

it ends up as http://www.somesite.com?somequery=?key1=value1&key2=value2 in firefox and IE7 which means that I can't parse the query string correctly.

I also tried using encodeURIComponent which didn't work either.

Is there another function or a hack to force the redirect to keep the somequery value escaped??

Answer 1

encodeURIComponent will work. (You may or may not want the leading ‘?’, depending on what the script is expecting.)

var c= 'd e'
var query= '?a=b&c='+encodeURIComponent(c);
var uri= 'http://www.example.com/script?query='+encodeURIComponent(query);
window.location= uri;

Takes me to:

http://www.example.com/script?query=%3Fa%3Db%26c%3Dd%2520e

When you hover over that it may appear once-decoded in the browser's status bar, but you will end up in the right place.

escape/unescape() is the wrong thing for encoding query parameters, it gets Unicode characters and pluses wrong. There is almost never a case where escape() is what you really need.