Hi, We are running Tableau Server 9.2 in our organization, and have started embedding our dashboards into several of our public-facing websites using trusted authentication and iframes. Since we are a public institution we must strive to be accessible, and have a QA team that is very thorough in testing.
One issue that was flagged was the iframes are returning the wrong DOCTYPE. According to the W3C spec, all HTML5 documents should use this doctype declaration.
However, the Tableau server is returning this:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Because the embedded HTML contains tags such as <CANVAS> it should use the HTML5 doctype declaration for the best compatibility.
I'm not the server admin (I'm just the BI Developer), so can someone let me know if the DOCTYPE being returned by the server is something that can be changed?
I would recommend contacting Tableau Support about this. Please let us know what you find