QtWebEngine debugging

Question

Recently Qt introduced the QtWebEngine module. Is there a way to invoke developer tools and debug JavaScript code inside QWebEngineView? It was possible with QWebView using

page()->settings()->setAttribute(QWebSettings::DeveloperExtrasEnabled, true);

but I couldn't find any similar option in QWebEngineView.

Answer 1

I just ran across this so I added it here for posterity.

It was just added to Qt 5.5 git. You have to enable it via an environment variable QTWEBENGINE_REMOTE_DEBUGGING=<port>. You can put 0.0.0.0:<port> if you are doing debugging of an embedded device and cant use the local console. Then you can point can connect to http://127.0.0.1: to get the debugger. It will need to be a chromium based browser. Do you have to use Chrome, or you can actually use the "quick nano browser" example if you want.

Answer 2

Alternatively, one may embed Firebug Lite to get a JavaScript console and inspectors.

Just add

<script type="text/javascript" src="https://getfirebug.com/firebug-lite.js"></script>

into the page. Pressing F12 will visualize the Firebug console.

Answer 3

From http://blog.qt.io/blog/2015/03/17/qt-5-5-alpha-available/:

The remote inspector can be used by either defining the env variable QTWEBENGINE_REMOTE_DEBUGGING, or by supplying the –remote-debugging-port command line argument. You can then point a browser at the specified port and inspect your web content.

Answer 4

If your devtools view and page are in the same program，use qt function to directly navigate to page devtools instead of http://localhost:port whith is devtools index(have to select devtools of whitch page).

After QTWEBENGINE_REMOTE_DEBUGGING being set up

>=5.13:

void QWebEnginePage::setDevToolsPage(QWebEnginePage *devToolsPage)

5.11~5.12:

void QWebEnginePage::setInspectedPage(QWebEnginePage *page)

Sample pyqt5.12

dev_view = QWebEngineView()  # new web view
self.page().setDevToolsPage(dev_view.page())  # self is the source web view

Reference:

https://doc.qt.io/qt-5/qwebenginepage.html#setDevToolsPage

https://doc.qt.io/qt-5/qwebenginepage.html#setInspectedPage

Answer 5

look this：

The Chromium DevTools provide the ability to inspect and debug layout and performance issues of any web content

https://doc.qt.io/qt-5/qtwebengine-features.html#chromium-devtools

Answer 6

For PyQt5 the following snippet:

        self.mainLayout = QtWidgets.QVBoxLayout()
        self.webView = QtWebEngineWidgets.QWebEngineView()
        self.mainLayout.addWidget(self.webView, 100)

        self.webView.settings().setAttribute(QtWebEngineWidgets.QWebEngineSettings.JavascriptEnabled, True)
        self.webView.settings().setAttribute(QtWebEngineWidgets.QWebEngineSettings.LocalContentCanAccessRemoteUrls, True)
        self.webView.settings().setAttribute(QtWebEngineWidgets.QWebEngineSettings.ErrorPageEnabled, True)
        self.webView.settings().setAttribute(QtWebEngineWidgets.QWebEngineSettings.PluginsEnabled, True)



        dev_view = QtWebEngineWidgets.QWebEngineView()
        self.mainLayout.addWidget(dev_view, 100)
        self.webView.page().setDevToolsPage(dev_view.page())