Can't get result from CallDevToolsProtocolMethodAsync

[ukandrewc]

Trying to call devtools protocol but not getting any results, I have Dev channel installed

Public Async Sub Test()
	Dim r = Await CoreWeb.CallDevToolsProtocolMethodAsync("DOM.getOuterHTML", "{}")
	Console.WriteLine(r)
End Sub

AB#27258673

[ukandrewc]

Not the same for all calls, "Network.getCookies", does work.

[ukandrewc]

It seems that ParametersAsJson may be the problem, I don't seem to be able to get a response when they are required.

This works:
CoreWeb.CallDevToolsProtocolMethodAsync("Network.getCookies", "{}")

Returns an empty array:
CoreWeb.CallDevToolsProtocolMethodAsync("Network.getCookies", "{""urls"":[""google.co.uk"",""www.google.com""]}")

[michael-russin]

For the cookies try adding the protocol. That works for me. For the DOM.getOuterHTML I haven't had any luck yet.

CoreWeb.CallDevToolsProtocolMethodAsync("Network.getCookies", "{""urls"":[""https://google.co.uk"",""https://www.google.com""]}")

[ukandrewc]

@michael-russin Cheers, didn't think of that. I was going on .Net where only domain is required.

[ukandrewc]

PS: I did try adding nodeId for getOuterHTML but nothing from that either.

[pagoe-msft]

@ukandrewc

Thanks for bringing this up - we have been investigating this and trying to determine if this is a bug on our side or a bug in CDP

[pagoe-msft]

@ukandrewc

This appears to be a bug on CDP side. I'll file a bug for them to look into and I've added a feature request on our end to provide better error messaging.

[ukandrewc]

@pagoe-msft Great, thanks. While we're on better error messaging, is there any way to log executeScriptAsync errors in devtools?

[pagoe-msft]

@ukandrewc

We don't have support for that right now - but that's a really interesting feature request. Could you open a new issue for that, so we can track it separately in our backlog?

[ukandrewc]

@pagoe-msft will do

[michael-russin]

You can get the getOuterHTML working by making 2 calls

// Get the document information
CoreWebView2.CallDevToolsProtocolMethodAsync("DOM.getDocument", "{}");

// parse the result JSON and read the nodeId

// get the outer html for the nodeId
CoreWebView2.CallDevToolsProtocolMethodAsync("DOM.getOuterHTML", "{\"nodeId\" : " +  nodeId + "}");

This will give the source you would see by doing an Inspect not what you would see with a View Source.

A basic sample can be found in the WebView2WindowsFormsBrowser project at https://github.com/michael-russin/WebView2Samples

[ukandrewc]

@michael-russin Thanks, that is what I wanted to find out. Is it just document.documentElement.outerHTML.
At the moment, I'm making an XHR call to get the source, but was wondering if it is available locally.

[champnic]

@ukandrewc Apparently even though the docs for getOuterHTML list all parameters as optional, at least one needs to be specified.

[ukandrewc]

Great, thanks.

[WirelessMistress]

If you specify {"nodeId":1}
to the
DOM.getOuterHTML
command,
my impression is it gives you the entire HTML View Source Content

[WirelessMistress]

Sorry my bad
lemme correct my previous post

// Get the document information
var documentString = CoreWebView2.CallDevToolsProtocolMethodAsync("DOM.getDocument", @"{""depth"":-1,""pierce"":false}");

//var id = parse using a System.Text.RegularExpressions.Regex
// for @"(""backendNodeId"":)([0-9]+) on documentString

// get the outer html for the nodeId
CoreWebView2.CallDevToolsProtocolMethodAsync("DOM.getOuterHTML", "{"backendNodeId" : " + id + "}");

and you get all the view Source of the HTML document html-decoded