Execute JS in RequestHandler

[BeanYa]

Background

CefSharp Version

88.2.90

.Net Version

.Net Framework 4.6

Description

I can execute JS code in FrameLoadEnd/FrameLoadStart/LoadingStateChanged by attach a async method

browser.FrameLoadEnd += async (s, e) =>{ await ... }

The page (a login page) I loaded use Vue.js and redirect by e.$router.push('/xxx').

The FrameLoadEnd/FrameLoadStart/LoadingStateChanged event wasn't triggered after e.$router.push('/xxx'). called.

But I found request handler can intercept that on OnBeforeBrowser.

So I implemented a class inherited from RequestHandler and override OnBeforeBrowser.

I need to do something with the redirect url.

What I trying to do.

In the override method OnBeforeBrowser, I execute a JS code document.getElementById('xx'), the task always show WaitingForActivation.

browser.CanExecuteJavascriptInMainFrame is true before execute that.

And I tried add a 3s timeout to ExecuteScriptAsync("document.getElementById('xx')", timeOut: TimeSpan.FromSeconds(3)), the task was always canceled and throw a exception.

Question

Is that I shouldn't execute JS code in the RequestHandler?

Is there any alternative solution to that?

[amaitland]

Is that I shouldn't execute JS code in the RequestHandler?

If you are asking can you evaluate JavaScript in OnBeforeBrowse? Only if you were to cancel the navigation.

Is there any alternative solution to that?

Without knowing what e.$router.push('/xxx') actually does I cannot say.

[BeanYa]

Thanks.

[amaitland]

Is the website a single page application(SPA)?

You can use DevTools to look at what's going on.

https://github.com/cefsharp/CefSharp/wiki/Trouble-Shooting#javascript-debugging

[BeanYa]

Yes, it's a SPA built by Vue.js.

It built by another team, and I need to login and get token from header.

And they don't exposed the API to us.

I already debug it and found out the page will redirect after e.$router.push('/xxx').

The old version of the login window was wrote by WebBrowser, the Navigating event was raised after e.$router.push('/xxx') call.

What I am doing is use CefSharp and Chromium to refactor that login window to improve performance.

I even tried AddressChanged event of CefSharp, but it still not been raised after the e.$router.push('/xxx') (Add a break point in DevTools).

Maybe I need to found another way to get that token or Debug that page again.

Thanks for your reply.

[amaitland]

If the token is actually a header then you can get it from the response.