QWebEnginePage: Solutions for running JavaScript and returning values from HTML document?

desun_evan

I have been using QWebEnginePage::runJavaScript();
with this being executed after loading a web page with QWebEnginePage::setUrl(); and calling a slot after QWebEnginPage::loadFinished();

I am running into a few issues.

1: runJavaScript returns values that change after being quickly called a second time. Usually this amounts to more elements found by querySelectorAll();..eventually the actual amount of elements the HTML page contains are returned... but sometimes this isn't true.
2: Certain pages do not return large groups of elements that querySelectorAll(); would normally return.

Is there a more sophisticated way to run and manage JavaScripts with QWebEnginePage? Or a better way altogether? Is this a injection point or worldid issue?

I am aware of QWebEngineScript class, although I'm not sure how to use this to execute a JavaScript. I have been introduced to Greasemonkey but don't know where to begin with chromium.

enjoysmath

@desun_evan

This seems like you want to use the QWebChannel api.

I did that one time following their API docs, and here is the result:

https://github.com/enjoysmath/Marked-KaTeX-example-cpp

It's a Markdown editor + KaTeX (for math type-setting) using a QWebEngineWidget and QWebChannel to pass data between. The host language is C++.

enjoysmath

@desun_evan Did you get solutions to this problem?

JonB

@desun_evan
@enjoysmath's QWebChannel may well be the correct way to go.

I have a recollection of using QWebEnginePage::runJavaScript() and QWebEnginPage::loadFinished() which just might be relevant.

I think page load finished comes before JS document ready event. I used runJavaScipt() to set document.onReady (or whatever it is, or jQuery ready()) to execute code which needed to be sure the document tree had been fully constructed. Worth a try for your case?

desun_evan

I will try these suggestions. Thank you very much!