QtWebEnginePage.runJavaScript

Rolln

https://doc.qt.io/qtforpython/PySide2/QtWebEngineWidgets/QWebEnginePage.html#PySide2.QtWebEngineWidgets.PySide2.QtWebEngineWidgets.QWebEnginePage.runJavaScript

In the C++ class you can use a callback to get the value returned from the javascript but it doesn't appear that you can get a return value/object with PySide2. Any suggestions would be great.

Rolln

Here is a basic example...
When using QT, temp = None.
When the same script is run using Selenium, temp = 5.

import sys
import time
from PySide2 import QtCore, QtGui, QtWidgets
from PySide2 import QtWebEngineWidgets
from PySide2.QtWebEngineWidgets import QWebEngineView

app = QtWidgets.QApplication(sys.argv)
view = QtWebEngineWidgets.QWebEngineView()
view.setUrl(QtCore.QUrl("https://google.com"))
view.show()
temp = view.page().runJavaScript('return 1+4')
print(temp)

import sys
import time
from selenium import webdriver

browser_options = webdriver.FirefoxOptions()
browser_options.add_argument('-headless')
browser = webdriver.Firefox(firefox_options=browser_options)
browser.get('https://google.com')
temp = browser.execute_script('return 1+4')
print(temp)
browser.close()
browser.quit()

skidooman

I found the answer here:

https://stackoverflow.com/questions/41780435/return-value-from-javascript-to-pyqt5

I faced the same issue, but in PySide. Back in PySide (1) I could do this:

self.page().mainFrame().evaluateJavaScript("getHits()")

but now, there is no more evaluateJavaScript() but a runJavaScript. This function can take only one or two params. Since it is asynchronous, you apparently have to pass a function as the second parameter. When the script finishes execution, it will call that second function and you will then get the data.

skidooman

Argh... seems PYQT5 can do this, but not PySide2.

https://bugreports.qt.io/browse/PYSIDE-643

Too bad since doing this was easy in PySide.

JonB

@skidooman
We convered this recently in https://forum.qt.io/topic/110659/q_arg-missing-in-python-how-to-use-invokemethod.
A couple of posts there claim workarounds, I didn't look at them but you might want to....