How to handle failed documentation lookup?

[Aerilius]

Currently, clicking ? always opens the documentation browser (if not yet open) and navigates to an error page. Especially in the editor, type inference is very likely unsuccessful and the appropriate documentation cannot be looked up (not to speak of tokens in custom scripts).

• Provide a hint in advance on which tokens documentation is available? (unfeasible, would require checking type on every token in the text)
• Don't show documentation browser, but a notification about the failure?
• Add to the error page a searchbox or link to a search engine? Which search engine?
• Add to the error page links to the overview pages of Ruby Core and SketchUp documentation

[Aerilius]

Browser controls around an iframe don't work with any website due to cross-origin issues (that real browser-chrome can override). This is an issue with sites like "rubydoc.info" which blocks being rendered in iframes and just displays white. This solution is not very useful.

The alternative is to revert back to loading the (guessed) documentation page into the top level of the HtmlDialog without browser controls. If we cannot find a matching documentation page, we (still) display a static error page where links to search engines could be added. However if we find a (seemingly) matching documentation page, there are no controls to navigate away in case the user does not find what he needs.