how do I make a script to receive an argument through a URL?

Question

I am new to JavaScript and I am trying to implement it into a website like this.

A person wants to download a file. They click on a link, which takes them to another HTML file with the download link, a keyword, and an advertisement.
So they would be on

http://website.com/randompage

And they would click on a link to download a file which would take them to

http://website.com/download.html?keyword=text?file_url=http://website.com/file.txt

If website.com/download.html could accept 2 parameters into an embedded JavaScript (or a seperate file, whichever works better). Then the download.html would show a link to download the file at variable file_url and would display the keyword from variable keyword. Then an ad would be displayed according to the keyword (my ad service does that for me).

Is this possible to do? I would like a sample script, if possible. The ad code can be left out (I already have that part).

You're looking for the query string: http://stackoverflow.com/questions/647259/javascript-query-string — T.J. Crowder, Aug 26 '13 at 12:08

Jeroen Ingelbrecht · Accepted Answer · 2013-08-26T16:40:24.717

2

<!DOCTYPE html>
<html>
<body>
  hi
  <script>
    function getParam(paramName){
  var prmstr = window.location.search.substr(1);
  var prmarr = prmstr.split ("&");
  var params = {};

  for ( var i = 0; i < prmarr.length; i++) {
     var tmparr = prmarr[i].split("=");
     params[tmparr[0]] = tmparr[1];
  }
  return params[paramName];
}

    document.write('File url: ' +getParam('file_url')+ 
    '<br/>File name: ' +getParam('file_name')+ 
    '<br/>Keyword: ' +getParam('keyword'));
  </script>
</body>  
</html>

edited Aug 26 '13 at 16:40

answered Aug 26 '13 at 12:12

Jeroen Ingelbrecht

808
5
11

And I use this with the function `` – Timtech Aug 26 '13 at 13:03
yes indeed, that's the definition of the $_GET function which you call to retrieve the URL parameter – Jeroen Ingelbrecht Aug 26 '13 at 13:05
Okay, thank you. I will accept this answer if my code works. It may take a while for me to implement it correctly. – Timtech Aug 26 '13 at 13:09
ok, in case of any related questions, shoot – Jeroen Ingelbrecht Aug 26 '13 at 13:11
In the body, I put `var params = window.location.search.split('?'); var file_url = $_GET('file_url','?'+params[1]);` and it displays as normal text. Do I have to use the ` – Timtech Aug 26 '13 at 13:15
yes you do. That way the browser knows you want to execute some code there. You might also need the `document.write()` method to write the file_url var: `document.write(file_url);` – Jeroen Ingelbrecht Aug 26 '13 at 13:22
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/36260/discussion-between-timtech-and-jeroen-ingelbrecht) – Timtech Aug 26 '13 at 13:23
i can't access denied by company policy.. what's the problem? – Jeroen Ingelbrecht Aug 26 '13 at 13:26
It does not display anything on the page even with document.write. Can I use javascript variables outside of the script tags? – Timtech Aug 26 '13 at 15:34
no, you cannot use js vars outside the script tags. Do you know JS Bin of jsFiddle? Can you paste your html and code there? – Jeroen Ingelbrecht Aug 26 '13 at 15:35
can you c/p the HTML in the question? – Jeroen Ingelbrecht Aug 26 '13 at 15:38
I wrote an example in the answer with html and js in the html – Jeroen Ingelbrecht Aug 26 '13 at 16:09
Okay, I will try it out soon. – Timtech Aug 26 '13 at 16:12
It seems to work. Could you add the perms `file_name` and `keyword` to the existing `file_url`? – Timtech Aug 26 '13 at 16:36
ok, i've altered the code – Jeroen Ingelbrecht Aug 26 '13 at 16:42
Um, `file.html?file_url=URL?file_name=FILE?keyword=KEY` displays: `hi File url: URL?file_name File name: undefined Keyword: undefined` Please help! – Timtech Aug 26 '13 at 17:30
Fixed! In the code, `prmstr.split ("&");` should be `prmstr.split ("?");` – Timtech Aug 26 '13 at 17:32
I accepted it. Thanks so much for your help! – Timtech Aug 26 '13 at 17:32

how do I make a script to receive an argument through a URL?

1 Answers1