Configuring Webpack build for file:// use in CEF - reactjs

Question

I have to develop a webapp for a CEF-Browser environment. There is no HTTP server available, everything will be served over file:// protocol.
When developing a Webapp nowadays one doesn't get round working with a framework like react/vue for frontend. The standard webpack build scripts of those build a bundle which only works served over HTTP.
Is it possible to configure webpacks build bundle to work on file:// or is there another way to use react or vue via file://?

Answer 1

I'm suggest read CEF wiki more carefully. You are especially interested in https://bitbucket.org/chromiumembedded/cef/wiki/GeneralUsage.md#markdown-header-request-handling
In short:
You can register custom scheme handler to serve resources over http+custom fake domain.
You can pack resources in zip for example if you like, or leave them at file system as is (but in that case you can expect that some funny users can edit your files, and then report back unexisting errors back to you).
Important helpers already done (but you can write own when need.)
You can... many other things.
Main thing that "file" scheme are more restricted, and for example you can't do XHR requests. But for custom handler you can. Even if dynamic loader for some reason use XHR instead DOM-based loading it will work again same as on http without touching network.
cefclient itself also has usage of custom schemes. Check URL of Tests->Other... in menu. :)
PS: Sorry that my answer doesnt have direct answer for your question. But, custom resource handling in CEF is so common, that i'm just should say about.

Answer 2

fddima is right - you don't need to configure your webpack (although it would be theoretically possible). Instead you can use custom scheme handler in CEF. I made it work with angular at work.
I wrote blog post on how to serve web application via 'file' protocol in CEF.
What you want to add is your scheme handler and its factory:
using System;
using System.IO;
using CefSharp;
namespace MyProject.CustomProtocol
{
public class CustomProtocolSchemeHandler : ResourceHandler
{
// Specifies where you bundled app resides.
// Basically path to your index.html
private string frontendFolderPath;
public CustomProtocolSchemeHandler()
{
frontendFolderPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "./bundle/");
}
// Process request and craft response.
public override bool ProcessRequestAsync(IRequest request, ICallback callback)
{
var uri = new Uri(request.Url);
var fileName = uri.AbsolutePath;
var requestedFilePath = frontendFolderPath + fileName;
if (File.Exists(requestedFilePath))
{
byte[] bytes = File.ReadAllBytes(requestedFilePath);
Stream = new MemoryStream(bytes);
var fileExtension = Path.GetExtension(fileName);
MimeType = GetMimeType(fileExtension);
callback.Continue();
return true;
}
callback.Dispose();
return false;
}
}
public class CustomProtocolSchemeHandlerFactory : ISchemeHandlerFactory
{
public const string SchemeName = "customFileProtocol";
public IResourceHandler Create(IBrowser browser, IFrame frame, string schemeName, IRequest request)
{
return new CustomProtocolSchemeHandler();
}
}
}
And then register it before calling Cef.Initialize:
var settings = new CefSettings
{
BrowserSubprocessPath = GetCefExecutablePath()
};
settings.RegisterScheme(new CefCustomScheme
{
SchemeName = CustomProtocolSchemeHandlerFactory.SchemeName,
SchemeHandlerFactory = new CustomProtocolSchemeHandlerFactory()
});