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I have the following HTML file stored on "C:\local.html":

<html>
<head>
<script type="text/javascript">

function execute()
{
    const urlParams = new URLSearchParams(window.location.search);
    const param = urlParams.get('param');
    var text_box = document.getElementById("path_text");
    text_box.value = param;
}

</script>

</head>
<body onload="execute()">

<textarea id="path_text" rows="40" cols="80" style="font-size:75%"></textarea><br/>

</body>
</html>

If I open the file in my web browser like "file:///C:/local.html?param=Some interesting text" I got web page with the text area that contains the text "Some interesting text" that was passed to the java-script by URL variable param.

Now I want to import the same file to Mathematica with the same URL parameter and then extract the content of textarea id="path_text" after the java script was executed.

The following code

Import["file:///C:/local.html?param=some dfsf"]

gives error "File was not found".

The following two codes gives no error but also gives no data, like the java-script code was not executed or/and the URL parameter was not passed.

Import["file:///C:/local.html", 
 Parameters -> {"param" -> "Some interesting text"}]

Import["C:\\local.html", 
 Parameters -> {"param" -> "Some interesting text"}]

How to import local HTML file with passed URL parameters to java-script and java-script executed?

UPDATE:

Using flinty's advise to use StartWebSession and WebExecute I figured out how to extract the content from text area by java-script code:

session = StartWebSession[Visible -> False];
WebExecute[
  "OpenPage" -> "file:///C:/local.html?param=Some interesting text"];
WebExecute[session, 
 "JavascriptExecute" -> 
  "return document.getElementById('path_text').value"]
DeleteObject[session]
Clear[session]

(*"Some interesting text"*)
Improve this question
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  • 2
    $\begingroup$ URLRead["file:///C:/local.html?param=some dfsf"] will download the html. But the JS will not execute. Mathematica is not a web browser. Have a look at StartWebSession and WebExecute in the documentation. You cannot do this exclusively within Mathematica. $\endgroup$
    – flinty
    Sep 4, 2020 at 14:40
  • $\begingroup$ Can WebExecute work with local HTML file? $\endgroup$
    – azerbajdzan
    Sep 4, 2020 at 15:15
  • $\begingroup$ Yes. WebExecute["OpenPage" -> "file:///C:/local.html?param=some%20dfsf"] $\endgroup$
    – flinty
    Sep 4, 2020 at 15:18
  • $\begingroup$ OK and then how I extract the content of the text area when the page is open with WebExecute? $\endgroup$
    – azerbajdzan
    Sep 4, 2020 at 15:21
  • $\begingroup$ WebExecute works fine for me. It should be opening firefox or chrome if installed. $\endgroup$
    – flinty
    Sep 4, 2020 at 15:59

1 Answer 1

Reset to default
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I can load the page with Firefox, and get the element. But I don't think Wolfram have implemented extracting attributes via XPath. Using "JavascriptExecute" works however.

session = StartWebSession[Visible -> False];
WebExecute[session, {
  "OpenPage" -> "file:///C:/local.html?param=some%20dfsf"
}]

(* here we try to get the element and it works *)
e = WebExecute[session, {
  "LocateElements" -> "XPath" -> "//*[@id='path_text']"
}]

(* here we try to get the .value attribute, but it won't work and returns {{}}.
 This XPath query doesn't even work in the Firefox console either. *)
a = WebExecute[session, {
  "LocateElements" -> "XPath" -> "//*[@id='path_text']/@value"
}]

(* we can try to execute js on the page to extract the attribute, this works *)
result = WebExecute[session, 
  "JavascriptExecute" -> "return document.getElementById('path_text').value"]

DeleteObject[session]
Improve this answer
$\endgroup$
1
  • $\begingroup$ Anyway it is a very cumbersome way of doing it but now we can use any java-script code, pass some parameters to it from Mathematica, execute java-script and then get the results back to Mathematica. Still less cumbersome than installing NodeJS and all its dependencies to just find out it will not work anyway. $\endgroup$
    – azerbajdzan
    Sep 4, 2020 at 16:20

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