Connecting to different Targets

[ordinaryorange]

In devtools protocol a call to Target.attachToTarget will return a sessionId of the newly established session to given target.
"flat mode" can then be used to issue commands to any connected target session
e.g. the raw message will look like this
{method: "Devtools.method", "params": {"method params"}, "sessionId": "123456789"}

The Cefsharp.Dom API does not look like it support multiple sessions ?
Is there workaround to issue commands over different sessions ?
Is this on the radar for this lib ?

[amaitland]

e.g. the raw message will look like this
{method: "Devtools.method", "params": {"method params"}, "sessionId": "123456789"}

CEF doesn't support passing in a session ID that I'm aware of. Commands are send directly to the CefBrowserHost.

https://github.com/chromiumembedded/cef/blob/b318adddacccffb74bac95e49ac31b606d8b813e/include/cef_browser.h#L575

Is there workaround to issue commands over different sessions ?

I don't believe it's currently possible. By all means double check the CEF source.

[amaitland]

I have a webpage in Cefsharp that produces a popup, and I need to run some JS on the popup. I checked out if I could grab the window via a LifespanHandler, but discovered it is not possible to start a new Cef browser, block the native one and return the Cef window handle.

Not quite sure what you mean by this.

Creating a devtoolscontext for a popup should already be possible, just no extension method for it yet. You can implement your own though. You'll need a lifespanhandler.

https://github.com/cefsharp/CefSharp.Dom/blob/main/lib/PuppeteerSharp/WebBrowserExtensions.cs#L58
http://cefsharp.github.io/api/104.4.x/html/M_CefSharp_IBrowser_GetHost.htm

[ordinaryorange]

I think we have crossed wires. I'll try and re explain.

I kick off a CefSharp browser and navigate to a website.
On that website is a button which I click, and a popup window appears. The popup occurs via the Window.open javascript function in the page. I note in the source js of the page that a reference to the WindowProxy object is maintained (var winproxy = Window.open), giving scoped access to the popup window for the rest of the calling code (which is important).

So I tried hooking up an OnBeforPopup to try and intercept the new popup.

The IWebBrowser and IBrowser that are passed in refer to the original parent window. So any Devtools access via those references will only result in the CDP Target being the original host page. (and it is not possible to access the "native" popup window via that Target)

What I attempted to do was to start a new Cef browser with the associated IPopupFeatures and IWindowInfo settings, which I can do, but then I need to assign that browser to the out newBrowser argument (so a window proxy might hopefully be returned to the calling js), and also return true to block the original native window. But this just throws a NotSupportedException. I did see this issue in case you ask.

So if I cant make a CefPopup (which would give me direct CDP access to that popup). Unless I've totally missed something here.

My current idea is to hook into the "native" popup via CDP by attaching to it via the Target.attachToTarget command. This will return a sessionId and from there I can then run any CDP method against that session (in what is called 'flat' mode) so long as the sessionId is included in the CDP message.

So in theory I could pass a manually constructed CDP message (which includes a sessionid) to the CefBrowser that invoked the 'native' popup, and the chromium infrastructure would effectively run that CDP message in the context of the popup.

The Cef method I referenced above says

//Send a method call message over the DevTools protocol. |message| must be a
// UTF8-encoded JSON dictionary that contains "id" (int), "method" (string)
// and "params" (dictionary, optional) values.

At a guess I reckon Cef wont touch the message and simply pass it onto the chromium infrastructure, and if the message has an additional sessionId it all might just work. If I had access to an equivalent method in CefSharp or Dom (and it worked), I could dump using PuppeteerSharp, but I cant seem to find such method.

Sorry, long winded, but just wanted to eliminate confusion.

[ordinaryorange]

Ha, I just found it. browser.GetBrowserHost().SendDevToolsMessage() going to try now....

[amaitland]

The IWebBrowser and IBrowser that are passed in refer to the original parent window. So any Devtools access via those references will only result in the CDP Target being the original host page. (and it is not possible to access the "native" popup window via that Target)

That is before the popup is created as the name implies, you need OnAfterCreated to get a reference to the IBrowser instance associated with the popup. I'd suggest you try that without attempting any other changes in LifeSpanHandler.

So if I cant make a CefPopup (which would give me direct CDP access to that popup). Unless I've totally missed something here.

What are you trying to do with the popup exactly? Are you using WinForms of WPF?

[ordinaryorange]

Yep, I totally missed something here....

You are correct. OnAfterCreated and the IBrowser are what I need. I completely overlooked it.
I just tested the CDP execution context on the IBrowser and it is working beautifully.
Your help has been invaluable, I should have asked this earlier and would have got 3 days of my life back...
You can definitely mark this one as answered!