topic Re: Calling Revit command from chromium browser. in Revit API Forum

Calling Revit command from chromium browser.

Andrej.Licanin — Fri, 01 Dec 2023 14:19:22 GMT

This is another guide on chromium browser using cef sharp. Hope some one finds it usefull.
This is a continuation of this post : Solved: Simple WPF with a chromium browser guide - Autodesk Community - Revit Products

Basicly what I wanted was for a button in the browser (on a webpage) to trigger a command in revit. This works by "binding" a javascript method to a c# object and its method. In the Javascript we await for the object and call its function.

So lets make a dummy object for binding and a method in it. In order to call a Revit method it will need a reference to an external event handler and its event.

public class BoundObject { public int Add(int a, int b) { ExtApp.handler.a = a; ExtApp.handler.b = b; ExtApp.testEvent.Raise(); return a+b; } }

The event and its handler are saved in the External app as static for ease of access.

internal class ExtApp : IExternalApplication { public static IExternalApplication MyApp; public static ChromiumWebBrowser browser; public static ExternalEvent testEvent; public static MyEvent handler; public Result OnShutdown(UIControlledApplication application) { // Cef.Shutdown(); return Result.Succeeded; } public Result OnStartup(UIControlledApplication application) { MyApp = this; //code for making a button handler = new MyEvent(); testEvent= ExternalEvent.Create(handler); return Result.Succeeded; } }

In the wpf the browser is embeded like this

and the code behind of the window is :

public TestWindow() { InitializeComponent(); ChromiumBrowser.Address = "https://www.google.com"; ChromiumBrowser.Address = "C:\\Users\\XXX\\Desktop\\index.html"; BoundObject bo = new BoundObject(); ChromiumBrowser.JavascriptObjectRepository.Register("boundAsync", bo, true, BindingOptions.DefaultBinder); } public void Dispose() { this.Dispose(); }

So to use it make an index.html and make the path to it in the browser address.

The Test webpage look like this:

<html> <head> <title>Bridge Test</title>  <script type="text/javascript"> async function callCSharpAction() { await CefSharp.BindObjectAsync("boundAsync"); boundAsync.add(16, 2); } </script> </head> <body> <button id="action1" onclick="callCSharpAction()">Action 1</button> <button id="action2" onclick="alert('Button is working')">Action 2</button> <button id="action3">Action 3</button> </body> </html>

The handler code:

internal class MyEvent : IExternalEventHandler { public int a; public int b; public void Execute(UIApplication app) { TaskDialog.Show("yoyoy", "data is "+a.ToString()+" and "+b.ToString()+"."); } public string GetName() { return "YOYOOY"; } }

Re: Calling Revit command from chromium browser.

jeremy_tammik — Fri, 01 Dec 2023 14:56:56 GMT

Thank you very much indeed for a very nice example of implementing a minimal external event and using it to call Revit from outside, from a modeless context. This is a perfect fit for The Building Coder topic group:

https://thebuildingcoder.typepad.com/blog/about-the-author.html#5.28

I'll gladly add it to the blog next week, if I may. Happy weekend to you!

Re: Calling Revit command from chromium browser.

Andrej.Licanin — Fri, 01 Dec 2023 15:21:25 GMT

Sure Jeremy, id love to see what people can do with it 🙂

Re: Calling Revit command from chromium browser.

Andrej.Licanin — Wed, 06 Dec 2023 08:11:17 GMT

To make a callback from c# function to the browser, you just need an instance of the browser, and a function in the javascript code that will be called.

here is an edited index.html

<html> <head> <title>Bridge Test</title>  <script type="text/javascript"> async function callCSharpAction() { await CefSharp.BindObjectAsync("boundAsync"); boundAsync.add(16, 2); } function showAlert(arg1) { // Your JavaScript logic here alert("Function called with arguments: " + arg1); return ; } </script> </head> <body> <button id="action1" onclick="callCSharpAction()">Action 1</button> <button id="action2" onclick="alert('Button is working')">Action 2</button> <button id="action3">Action 3</button> </body> </html>

and in our bound class we save a instance to the browser so we can use it on command

public class BoundObject { public int aS; public int bS; internal ChromiumWebBrowser browser; public void CallCSharpMethod() { MessageBox.Show("C# method called!"); // Add more code here as needed } public int Add(int a, int b) { ExtApp.handler.a = a; ExtApp.handler.b = b; ExtApp.testEvent.Raise(); return a+b; } public int SendSomeDataFromLocal(int a) { browser.ExecuteScriptAsync("showAlert("+a.ToString()+")"); return a; } }

i passed it when i created the browser in the window codebehind.

public TestWindow() { InitializeComponent(); ChromiumBrowser.Address = "https://www.google.com"; ChromiumBrowser.Address = "C:\\Users\\XXX\\Desktop\\index.html"; BoundObject bo = new BoundObject(); //ExtApp.boundObj = bo; bo.browser = ChromiumBrowser; ChromiumBrowser.JavascriptObjectRepository.Register("boundAsync", bo, true, BindingOptions.DefaultBinder); }

finally you can call it from revit

public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { ExtApp.boundObj.SendSomeDataFromLocal(999); return Result.Succeeded; }

this concludes a round trip from the browser and back. I hope anyone reading this finds it usefull.