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c++internet-explorercommshtml

Reading "aria-label" via MSHTML returns NULL

I'm trying to read an HTML element's aria-label attribute using IE's getAttribute method in C++/COM but although this works fine for other attributes (including aria-labelledby) it returns VT_NULL for aria-label.

My code example looks like this:

CComVariant label;
elem->raw_getAttribute(CComBSTR(L"aria-label"), 0, &label);
if (label.vt == VT_BSTR && SysStringLen(label.bstrVal)) {
    // This is never reached
}

I get the same results when using 2 for the flags argument of getAttribute.

Sample HTML here.

When I try using getAttribute in JavaScript in the browser this works perfectly but for some reason I can't reach this attribute using COM.

Am I missing something here?

Solution

  • In my experience, some new new HTML5 attributes are accessible via DOM Level 3 getAttributeNode method (available in IHTMLElement4).

    E.g., to make it work for placeholder attribute, I had to use WebBrowser Feature Control and enable HTML5 for the web page with <!DOCTYPE html> and <meta http-equiv="x-ua-compatible" content="IE=Edge"/> (which is a good idea in either case).