Parse JavaScript with jsoup

Question

In an HTML page, I want to pick the value of a javascript variable.
Below is the snippet of HTML page:

<input id="hidval" value="" type="hidden"> 
<form method="post" style="padding: 0px;margin: 0px;" name="profile" autocomplete="off">
<input name="pqRjnA" id="pqRjnA" value="" type="hidden">
<script type="text/javascript">
    key="pqRjnA";
</script>

My aim is to read the value of variable key from this page using jsoup.
Is it possible with jsoup? If yes then how?

Answer 1

Since jsoup isn't a javascript library you have two ways to solve this:

A. Use a javascript library

• Pro:

  • Full Javascript support

• Con:

  • Additional libraray / dependencies

B. Use Jsoup + manual parsing

• Pro:

  • No extra libraries required
  • Enough for simple tasks

• Con:

  • Not as flexible as a javascript library

Here's an example how to get the key with jsoupand some "manual" code:

Document doc = ...
Element script = doc.select("script").first(); // Get the script part


Pattern p = Pattern.compile("(?is)key=\"(.+?)\""); // Regex for the value of the key
Matcher m = p.matcher(script.html()); // you have to use html here and NOT text! Text will drop the 'key' part


while( m.find() )
{
    System.out.println(m.group()); // the whole key ('key = value')
    System.out.println(m.group(1)); // value only
}

Output (using your html part):

key="pqRjnA"
pqRjnA