[PyQt] Cancelling QtWebEngine authentication with PyQt

[Phil Thompson]

On 14 Dec 2016, at 11:38 am, Florian Bruhin <me at the-compiler.org> wrote:
> 
> * Phil Thompson <phil at riverbankcomputing.com> [2016-12-14 11:08:15 +0000]:
>> On 6 Dec 2016, at 6:06 am, Florian Bruhin <me at the-compiler.org> wrote:
>>> 
>>> Hi,
>>> 
>>> QtWebEngine requires setting the passed QAuthentication pointer to an
>>> empty QAuthenticator to cancel authentication
>>> ("*authenticator = QAuthenticator();" in authenticationRequired), see
>>> the note here:
>>> 
>>> http://doc-snapshots.qt.io/qt5-5.7/qtwebenginewidgets-qtwebkitportingguide.html#qt-webengine-does-not-interact-with-qnetworkaccessmanager
>>> 
>>> Unfortunately I can't see a way to do this from PyQt, apart from
>>> using setHtml to display some error (which seems a bit hacky to me):
>>> 
>>> https://github.com/kovidgoyal/vise/commit/749a9c693e4107c073a90042b079dc658ad73564
>>> 
>>> Not sure what the best way to solve this would be though...
>> 
>> Sorry, I'm not understanding. What is it you want to do in Python that you can't?
> 
> QtWebEngine calls authenticationRequired with a pointer to a non-null
> QAuthenticator.
> 
> To cancel the authentication, the passed pointer needs to be set to a
> new null QAuthenticator:
> 
>    // slot connected to QWebEnginePage::authenticationRequired
>    void Foo::handleAuthenticationRequired(const QUrl &url, QAuthenticator *authenticator)
>    {
>        *authenticator = QAuthenticator();
>    }
> 
> Since PyQt's signature is also "QUrl, QAuthenticator" (i.e. my code
> gets a QAuthenticator as argument, it doesn't return any) there's no
> way for it to return None or a new null QAuthenticator.
> 
> Solutions I can think of (unless I'm missing something):
> 
> - Having something like:
>  sip.writepointer(authenticator, QAuthenticator())

I've called it assign() as it invokes the assignment operator.

The following code works...

import sip
from PyQt5.QtNetwork import QAuthenticator

a = QAuthenticator()
assert a.isNull()

a.setUser("foo")
assert not a.isNull()

sip.assign(a, QAuthenticator())
assert a.isNull()

It is in current hg and tonight's snapshot.

Phil