How to extract WebElementObject's attributes?

Question

For example one can get WebElementObject like so:

el = WebExecute[{"OpenPage" -> "mathematica.stackexchange.com", 
   "LocateElements" -> "XPath" -> "/html/body/header[2]/div/a"}][[2,1]]

Right now it seems the only way to extract element attributes (e.g. href for <a> tag) with WebExecute framework, is to write some JavascriptExecute query. Is there a more straight forward solution?

Answer 1

As of 12.3 (I haven't checked the earlier versions), there is an undocumented command ElementAttribute to extract attributes:

session = StartWebSession[]; 
WebExecute["OpenPage" -> "https://wolfram.com"]; 
elements = WebExecute["LocateElements" -> "CSSSelector" -> "div > a.item-0"]; 
WebExecute["ElementAttribute" -> {First@elements, "href"}]
(* "https://blog.wolfram.com/2021/11/30/six-reasons-why-the-wolfram-language-is-like-open-source/?source=frontpage-news" *)

How did I discover it, you ask? Well, it's one of the commands that is defined in /Applications/Wolfram Desktop.app/Contents/SystemFiles/Components/WebUnit/Kernel/wdElement.m, so I just tried it and it seems to work - probably an omission on Wolfram Research's part to not include it in the documentation.

Answer 2

After some spelunking into WebUnit`Private, I've found some helpful functions like get, fetch and attribute, that could be used to do exactly what I need:

getAttribute[element_WebElementObject, attribute_String] := 
 getAttribute[$CurrentWebSession, element, attribute]

getAttribute[session_WebSessionObject, element_WebElementObject, attribute_String] := 
 With[{sessionInfo = session /@ {"SessionID", "Browser", "URL"}}, 
  WebUnit`Private`attribute[sessionInfo, element["ElementId"], attribute]]

Hope it would be included in some form as an official documented functionallity in the future.