Handling errors in QWebView / QWebPage - qt

Question

I wish to get more information than just success = false in loadFinished (this is most often just a canceled load). From the documentation and other posts on this site, I gathered I should subclass QWebPage and override the extension() method to handle the ErrorPageExtension.
However, I'm not getting it to work, i.e., no matter what I try my extension method does not get called. I'm probably doing something really stupid but not seeing it. Basically my class looks like this:
class MyWebPage : public QWebPage
{
Q_OBJECT
public:
MyWebPage(QObject* parent = 0) : QWebPage(parent) {}
virtual bool extension(Extension extension,
const ExtensionOption* option = 0,
ExtensionReturn* output = 0)
{
// blah
}
virtual bool supportsExtension(Extension extension)
{
// blah
}
};
The implementation of the methods is not the problem, I have a breakpoint there and it never gets called. I create an instance like
MyWebPage* page = new MyWebPage(this);
mUi.WebView->setPage(page);
I'm a bit uncertain about the life time of a QWebPage object in QWebView, but from my tests it seems the QWebPage always remains the same instance and simply loads new content. So I assumed I should simply give my page to the QWebView, I didn't see another way to make it use my derived class. But when loading bogus URLs, non-existing local files, or unsupported content, either via the WebView or directly via the mainframe of the page, I never get the call with ErrorPageExtension information.
Any help is appreciated. This is using Qt 4.8.2.

Answer 1

There is a bit mistake:
...
virtual bool supportsExtension(Extension extension) const // const!!!
{
return QWebPage::ErrorPageExtension === extension;
}
...
You forgot to copy the const modifier.