HTML5 Validator Plus is an enhanced version of Roger Johansson's HTML5 Validator, a Firefox add-on that helps with validating HTML(5) source using the validator.nu engine (online or local instance).
For historical reasons, HtmlValidatorPlus has retained the old id from the original branch, namely "[email protected]". I think the time has come to change that. Unfortunately, that will cause trouble for those who are upgrading from an old version, since old version will not be removed in the upgrade; that will have to be done manually.
The pages I was trying to validate were password protected and non-cacheable (has the do not cache header). When I tried to validate the page, the request to load the page got re-directed to the login page because the authentication cookie was not sent to the server. That is, I could only validate the login page. After turning everything off, hacking the code and trying another profile I found the reason: third party cookies. When I added localhost (I was serving from localhost) to the white list of cookie exceptions in the security/history preferences it all worked. So if you are using custom preferences for Security/History this will affect you and you'll need to add the server to the list of allowed exceptions.
When I try to run this extension in Firefox 49.0, it does not work. The icon is displayed in the toolbar but nothing works. I don't know in what Firefox version this started happening, or what causes the problem.
I would like to store the preferences under the key "html5validatorplus" instead of the old "html5validator". That will enable rogerjohansson/html5validator and this extension to co-exist, but it will force upgrading users to reconfigure from scratch.
If the user has opened another tab in the results window and that tab has focus, clicking the toolbar to view the results page has no apparent effect, other than filling the results page with messages in the background. It is unclear why Firefox will not even switch to the results window in this case.
How to reproduce:
Make sure you have a results window.
Open a new tab in the results window and make it the active tab in that window.
In your main window, set up a validation with a result to view.
Click the toolbar icon to view the validation result.
Expected behavior: Firefox should switch to the results window and activate the results page.
Actual behavior: Firefox seemingly does not react at all, but the results page is populated as it should.