Loading a platform depended library from the Plugin folder does not work, a String.Empty is returned and the file is not found.

Resolution: return a null value instead, this triggers the flow of returning a platform candidate

First let me say, remarkable work. This is absolutely the closest I've found to the "holy grail" of hot-swappable MVC controllers & views. That it unpacks nuget packages and loads from there is 100% what I've dreamt of (short of a service that polls nuget feeds and downloads updates to the plugins folder).

I tried adding Prise to a solution with one main WebApp and several Razor Class Libraries with their own views and controllers and was able to load/update one of the RCL projects at runtime. The only flaw I ran into there was that the views (usually merged into the main project at build/start) weren't found so I could only return content results.

I may be pushing this farther than was intended, or farther than anyone has time to devote to making possible but if down the road you could reference & update RCL packages at runtime that would be a stunning achievement.

Thanks again!

James White

First, define Plugin in as follows:

    [Plugin(PluginType = typeof(IPlugin))]
    public class ActivityPlugin : IPlugin
    {
    }

    [PluginBootstrapper(PluginType = typeof(ActivityPlugin))]
    public class PluginBootstrapper : IPluginBootstrapper
    {
        public IServiceCollection Bootstrap(IServiceCollection services)
        {
            var config = services.BuildServiceProvider().GetRequiredService<IConfiguration>();
            System.Console.WriteLine("elsa config: {0} / {1}", config.GetSection("Elsa").Value, config["Elsa"]);
            var timerConfig = config.GetSection("Elsa:Timers");

            // check value here, if not then throw 
            if (string.IsNullOrEmpty(timerConfig.Value))
            {
                throw new ArgumentNullException("please config Elsa:Timers in appsettings.json");
            }
            return services.AddTimerActivities(options => options.Bind(timerConfig));
        }
    }

Then, host config settings

 // does it is necessary ?
 // services.AddSingleton<IConfiguration>(Configuration);

 // This is required for our razor pages to be found
 // services.AddRazorPages().AddRazorRuntimeCompilation();
  services.AddPrise<IPlugin>(options => {
          var builder = options.WithDefaultOptions(Path.Combine(AppDomain.CurrentDomain.BaseDirectory ?? "", "Plugins"))
       .AddPriseRazorPlugins(Environment.WebRootPath)
       .IgnorePlatformInconsistencies()
       .ScanForAssemblies(composer => composer.UseDiscovery())
        // Find the code in example project, how magic comes in here ?
        .UseHostServices(services, new[] { typeof(IConfiguration) }) 
        .WithAssemblySelector<AssemblyPluginSelector<IPlugin>>();
 });

But, when run the host

I am using Prise Plugin Framework and MailKit SMTP Client.

During the ConnectAsync call, if the async call timeouts, it will throw a TaskCanceledException. This will be caught in the caller and after logging it will be thrown down the call stack. But this will not be caught after the Execute method in the Prise plugin and the app will crash - other exceptions are being caught fine and don't crash the app.

try
{
    await _smtpClient.ConnectAsync(sendEmail.Host, sendEmail.Port);
    // other code
}
catch
{
    // logging
    throw;
}

This code is being called by the plugin with return await service.ExecuteAsync(parameters, context);

I'm expecting this to throw the exception to its parent but it doesn't happen.

The plugin looks as follows:

[Plugin(PluginType = typeof(IPlugin))]
public class Email : BasePlugin<EmailInputModel>
{
	[field: PluginService(ProvidedBy = ProvidedBy.Host, ServiceType = typeof(IServiceProvider))]
	private IServiceProvider ServiceProvider { get; set; }

	[PluginActivated]
	public void OnActivated()
	{
		InitializeServices(ServiceProvider);
	}

	protected override async Task<PluginExecutionResult> ExecutePluginAsync(
		InputModel parameters,
		PluginExecutionContext context,
		IServiceProvider provider)
	{
		IEmailPluginService service = provider.GetRequiredService<IEmailPluginService>();
		return await service.ExecuteAsync(parameters, context);
	}
}

Some time ago I read somewhere you were working on a VS 2022 version of the extension. Was that ever completed and if so, where can I find it? Thanks.

When running a netcoreapp2.1 project using Prise 1.7.0, the following error occurs:
System.IO.FileNotFoundException: 'Could not load file or assembly 'System.Reflection.DispatchProxy, Version=4.0.6.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. The system cannot find the file specified.'

Hi, I just found this and the library seems awesome. I will definitely give it a try. I was just wondering if I could use this to map routable and not routable razor components to the host project, similar to how the MVC stuff works.

if you have

public interface IService { }  
public class ServiceA : IService { }
public class ServiceB : IService { } 

usually, one can register different implementations of an interface with the ServiceCollection:

services.AddSingleton<IService, ServiceA>();
services.AddSingleton<IService, ServiceB>();

and later retrieve a list of different implementations by

using Microsoft.Extensions.DependencyInjection;

var services = serviceProvider.GetServices<IService>();
var serviceB = services.First(o => o.GetType() == typeof(ServiceB)); 

// or (if IService has a Name property)

var serviceZ = services.First(o => o.Name.Equals("Z"));

However, when using Prise

services.AddPrise<IService>(options =>
   options.WithPluginPath(path).
   WithPluginAssemblyName(name), ServiceLifetime.Singleton);

it is possible to register different implementations of the same interface, but GetServices() only returns the last registered entry.

Do I miss some specific configuration / options or is there a (clean) workaround ?

I am struggling with setting up a basic use case for our application. While the examples work easily enough, the problem is that most of our plugins have a number of dependencies, some of which are nuget packages hosted in our DevOps Artifacts in Azure. I looked at the Prise source code to see how it handled nupkg files and it's pretty clear that it only does a simple unzip and does not handle any kind of dependency resolution. Does this imply that any dependencies that the plugin has (all the way down the dependency chain) must be either referenced by the host or be part of the plugin assembly directory?

On a related note, the first time I attempted to run the project, I had the plugin dll in the directory by itself. Upon running the program, Prise told me that it could not load the plugin because Microsoft.Extensions.DependencyModel was missing. So I thought I'd just drop it into the plugin directory, but that did not work. I even tried adding an explicit nuget reference to the package and that did not work either. I verified that the dll is in the host's bin directory. I am running an Azure Function app. Here is the error:

Prise: Could not load file or assembly 'Microsoft.Extensions.DependencyModel, Version=3.1.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified.
[2021-10-25T22:48:12.347Z] Evaluate failed:    at Prise.AssemblyLoading.DefaultPluginDependencyContextProvider.FromPluginLoadContext(IPluginLoadContext pluginLoadContext)
[2021-10-25T22:48:12.350Z]    at Prise.AssemblyLoading.DefaultAssemblyLoadContext.LoadPluginAssembly(IPluginLoadContext pluginLoadContext)
[2021-10-25T22:48:12.352Z]    at Prise.DefaultPluginLoader.LoadPlugin[T](AssemblyScanResult scanResult, String hostFramework, Action`1 configureLoadContext)

I have a scenario where the Base plugin contract can be implemented in multiple ways for different use cases. All the plugin implementations are loaded into the Host app in different Assembly Load Contexts. Since the host app doesn't have control over the code written into the plugins, how can it terminate a plugin execution if it's taking longer than a specific timespan?

I have tried using cancellation token as an argument to the methods specified in the base plugin interface, but it's the responsibility of the implementation to co-operate with the cancellation. Is there a way to enforce termination from the host app/ calling method?

When creating a plug-in contract using an async method that just returns a Task, I get this exception when trying to call the plug-in through Prise:

System.Text.Json.JsonException: 'A possible object cycle was detected which is not supported. This can either be due to a cycle or if the object depth is larger than the maximum allowed depth of 0.'

It's quite easy is to replicate:

    public interface IMyPlugin
    {
        public Task TestAsync();
    }

    [Plugin(PluginType = typeof(IMyPlugin))]
    public class MyPlugin: IMyPlugin
    {
        public async Task TestAsync()
        {
            await Task.Run(() => Console.WriteLine("Inside of plug-in.")).ConfigureAwait(false);
        }
    }

On the host side, just call:

await plugin.TestAsync().ConfigureAwait(false);

and you get the exception above.

If you change the return to Task<string> or something else, it seems to work fine.

Fra mw ork => Framework ?

When multiple runtimes are installed on the Host:
2.1.811
3.1.404
5.0.100

And the host is configured to run as 3.1 application, then loading the System.Runtime 5.0.0 fails.
Expected behaviour: when the host is operating using the 3.1 runtime, the 3.1 runtime assemblies must be loaded, even though 5.0 assemblies are available on the host.

Obligation to use a prise.plugin.json file?

Can we imagine leaving the customisation of the name of this file? 🤔

To get routing to work with blazor server side - I have to add the loaded plugin assemblies to the router

<Router AppAssembly="@typeof(App).Assembly" AdditionalAssemblies="@_pluginAssemblies">

This then seems to render the loaded plugins fine, until I try to inject plugin services - I can inject things I declare directly in the host (such as config services, etc), but I cannot inject services I've created and set up in the plugin (using bootstrapper and PluginService, etc), it seems to tie the assembly to the host IServiceProvider.

Additionally, I noticed the MvcPluginLoader does not fire the activated method, so i did this manually using IPluginActivator.

When debugging, after the second or third Unload of the .NET Core 3.0 AssemblyContext, the debugger halts and the application stops with an error code 0x80070057.

Add option to extract all .nupkg files and let the consumer decide which one to load.

Hey Maarten

Are you open to work on a project where we need integrate your Prise?

Thanks
Nick

I need to call Prise plugin publish command from the Project Post Build Events.

I will jump into research to find out how to do it, but I f you can post example or instructions will be great.

Thanks for this useful code !

how to dotnet pack , let it include xx.deps.json file?

When multiple runtimes are installed on the Host:
2.1.811
3.1.404
5.0.100

And the host is configured to run as 3.1 application, then loading the System.Runtime 5.0.0 fails.
Expected behaviour: when the host is operating using the 3.1 runtime, the 3.1 runtime assemblies must be loaded, even though 5.0 assemblies are available on the host.

Is there any possibility to add plugins as a singleton instance? For example if a plugin wants to keep some state over the time of its execution. It seems that the whole design is currently focused on creating a plugin instance per scope.

I came across this interesting c# plugin loader, which is awesome and attract my interest to explore more.

This plugin loader is able to load DLL externally. On the other hand, it raises a security concern. Let's say the DLL is develop by external developer which may pose some security risk.

How can we control the loaded plugin such that it runs in a limited or isolated environment. E.g. the plugin has limited access to the file systems at the server?

Hi,

First off nice library, second of all I'm trying to get the Prise.Mvc to work with Dependency Injection. I got it to work when when loading the plugins in ConfigureServices however when I move it to Configure it can't initialize the plugin.

This is my code for activating the plugins:

           using (var scope = services.BuildServiceProvider().CreateScope())
            {
                var pathService = scope.ServiceProvider.GetRequiredService<IPathService>();
                var mvcPluginLoader = scope.ServiceProvider.GetRequiredService<IMvcPluginLoader>();
                var pluginLoader = scope.ServiceProvider.GetRequiredService<IPluginLoader>();
                var builder = scope.ServiceProvider.GetRequiredService<ApplicationPartManager>();


                var plugins = await mvcPluginLoader.FindPlugins<IPluginMvc>(pathService.GetPluginPath());

                foreach (var assemblyScanResult in plugins)
                {
                    Console.WriteLine(assemblyScanResult.ContractType);

                    var plugin = await mvcPluginLoader.LoadPluginAssembly<IPluginMvc>(assemblyScanResult);
                    builder.ApplicationParts.Add(new PluginAssemblyPart(plugin.Assembly));
                }
            }

And this is my controller in the plugin:

public class TestController : ControllerBase
    {
        private readonly ILogger<TestController> _logger;
        private readonly IPathService _pathService;

        public TestController(ILogger<TestController> logger, IPathService pathService)
        {
            _logger = logger;
            _pathService = pathService;
        }

        [HttpGet("Test")]
        public IActionResult Test()
        {
            _logger.LogInformation("Test called!");
            return Ok(_pathService.GetPluginPath());
        }
    }

I'm using the latest version of the plugin and .NET 5.0

When debugging in VS Code, the host application suddenly halts after x number of calls.

I'm searching to use this framework to manage some plugins in a .NET Core console app (.NET Core 3.1)
I'm sure that the problem is on my side, but I'm not able to adapt the code from your samples to my application.

Is it possible to have a simple sample for a Console App?

In my app I obtain this error: "System.TypeLoadException: 'Declaration referenced in a method implementation cannot be a final method....."

Hello ! I'm a student and for my internship, I've been trying to develop a 100% modular architecture and that's how I found your framework.
I've been trying to activate a SQL plugin using Entity, but the plugin is never found when the publish folder is scanned with the PluginLoader.
Here's the csproj of my plugin :

It's pretty much identical to your SqlPlugin in your samples.

To see if the problem came from my Prise configuration, I tried to implement the same contract with a test project without the Entity dependencies and it worked !
Since the only difference I've noticed in my publish folder was the lack of a folder called "runtimes", I re-published my normal sql plugin and deleted the folder. Now the plugin is scanned and found, but it can't be activated. Here's the stacktrace just in case :

I suppose this was to be expected, but now I'm a bit stuck and I don't understand how the folder can stop the loader from finding my plugin...

Also, all the projects I've been talking about have .NET 5.0 as their TargetFramework, except for my Contract which is aiming for netstandard2.0.

Do you have any idea how I could solve this ?
Thanks in advance and sorry if I wasn't clear enough !

Hello,

I wanted to know if it was simple to make a contract for plugins to access UI components, from the application.

This issue occurs when trying to load a newer Plugin (.NET Core 3.1) on a .NET Core 2.1 Host.

There is no known workaround to this other than to upgrade the Host to a newer runtime version.

I think that instantiating MAUI might be worthwhile.

We can start testing to see what changes we need to make to support cross platform plugins. 🔥 🔥

Steps to test:

• Create MAUI projet
• Create MAUI Contract
• Create MAUI Plugin

If the three steps above are achievable without change, then that's fine, otherwise we'll have to make the changes and implement cross-platform testing.

Steps in case of non compatibility:

• Define the items to be modified in Prise
• Define whether the changes made will not affect the other elements of Catch
• Define cross-platform testing
• Define samples MAUI for project

Hi, I'm starting on using the framework to try to manage a my library as a plugin.
I have downloaded all the samples to check how works the framework, but it's not easy, for me, without knowing the architecture.
For example is not clear how manage the 'compatibility' with older plugins.
My idea is to have a base contract with the version of the plugin, but I'm not sure if this is the correct way to allow the compatibility from older and newer plugins.

For this reason I'm asking if it's planned to write a wiki or a documentation on the framework.

Thanks

Consideration of other languages. Use of a wrapper to develop plugins in other languages and have them detected by Prise.

I'm using Prise in a dotnetCore3.1 windows service, that does plugin discovery in the ApplicationLifetime.ApplicationStarted Event to add new Web Controllers at runtime.

Everything works fine !, I'm able to invoke Web Modules Methods, access Host Configuration using the Proxy, and invoke Services registered by the Bootstrapper of each Controller.

I use an Interface to allow Prise discover the module on the ApplicationStarted Event : IWebModule

Later when perform a Http Get request to any Controller method (I have three controllers and three bootstrapper classes), the Bootstrapper event is called.

But then after continuous request, the Bootstrapper event and all services are been loaded again and again.
This seems to me like a performance issue. :(

How can I preserve the scoped ServiceCollection and use the same one over the calls?, there is some singleton services and all other are scoped services.

I would like to: when load the plugin, load the service collection and later be able to access some singleton services inside the Scoped service collection.

I'm developing a Health Check system to monitor the Web Module Status, that is perform getting some data from singleton services running inside the Web Module.

How can I inject type ILogger<MyService> in MyService class

Not sure if i am missing something. I am trying to update a 3.1 core project to .net 6 that using the Prise plugin framework. We have upgraded the nuget package to Prise 6.0.0 and the service.AddPrise() middleware method is no longer available. Is there any new documentation on migrating from .net core 3.1 to .net 6 for the Prise nuget package?

Hi

Firstly i just want to say thanks for creating this library, i am finding it very useful. However I have run into a hurdle around authorization on the controllers.

I am adding Authorization in my hosts startup like below:

services.AddAuthorization(options =>
 {
                options.DefaultPolicy = new AuthorizationPolicyBuilder(JwtBearerDefaults.AuthenticationScheme).RequireAuthenticatedUser().Build();
                options.AddPolicy("ApiUser", policy => policy.RequireClaim(Constants.Strings.JwtClaimIdentifiers.Rol, Constants.Strings.JwtClaims.ApiAccess));
            });

And then applying the authorize attribute to the controller :

[Authorize(Policy = "ApiUser")]
    [ResponseCache(NoStore = true)]
    [ApiVersion("1.0")]
    [ApiController]
    [Route("api/[controller]/[action]")]
    public class ServiceNowRequestController : ControllerBase

When i try and hit the api endpoint i get an error of "Request not found. The specified uri does not exist." However if i remove the authorize attribute i can call it fine.

I tried doing AddAuthorization again in the controller bootstrape but this results in the same error.

Is it possible to use Auth with plugins at all, if so can you point me in the right direction.

thanks in advance

This seems interesting. Can you add a sample project?

Hello there!

From what I understand you need to have plugins in a specific directory for the system to work. From the tutorial:

We will publish the OpenWeather.Plugin to the _dist folder created at the root of our project, which means that the WeatherForecastController needs to look for Plugins from that directory on the local disk.

If I have a solution with several projects, one of them being the host, and another being a plugin, can I make it work without copying files? I mean, just by clicking "play" in Visual Studio without manual steps? Maybe with project references?

Can this be made?
Thanks

Seeing the last commits seems to be 2 years ago - what's the state of this project?

Hi,
The URLS on the getting started page are all not found...
Just wanted to check the implementation since i'm developing a application which needs a plugin based architecture.

I have a .NET core 2.2 based Avalonia desktop application in which I want to use your framework. Let me know how shall I use your framework. Below is my current code for loading.

IServiceScope RegisterServices()
        {
            var collection = new ServiceCollection();

            var assemblies = AppDomain.CurrentDomain.GetAssemblies();
            foreach (var assembly in assemblies)
            {
                if (!assembly.FullName.StartsWith("Jaya", StringComparison.InvariantCultureIgnoreCase))
                    continue;

                var types = assembly.DefinedTypes;
                foreach (TypeInfo typeInfo in types)
                    if (typeInfo.IsClass && typeInfo.Name.EndsWith("Service", StringComparison.InvariantCulture))
                        collection.AddScoped(typeInfo);
            }

            var container = collection.BuildServiceProvider();
            var scopeFactory = container.GetRequiredService<IServiceScopeFactory>();
            return scopeFactory.CreateScope();
        }

This is more of question really, if anyone stumbled across this problem:

I run into an issue when trying to use load plug-ins from a test assembly, using dotnet test.
I've trived with both MSTest and xUnit, but essentially run into a mismatch of the .NETCoreApp version.
The contract, plug-in and the host have the <TargetFramework>netcoreapp3.1</TargetFramework> set.

Error:

 Test method Acme.LoadDummyPlugin threw exception: 
    Prise.PrisePluginException: Plugin framework version .NETCoreApp,Version=v3.1 is newer than the host .NETCoreApp,Version=v2.1. Please upgrade the host to load this plugin.

When I convert from a unit test to a console app, everything runs fine. But I'd love to create unit tests for the plug-ins.

Has anyone experienced this problem?

Why don't use PluginTypeName for FindPlugin?

My Situation is there have several implementation plugins within same assembly, so I can't use FindPlugin method to find specific plugin for execute.

I wish that assign PluginTypeName with implementation Type name and FindPlugin method can be implemented find by PluginTypeName as below.

PluginTypeName = implementation.Name, in public virtual Task<IEnumerable<AssemblyScanResult>> Scan(IAssemblyScannerOptions options)

wish be .FirstOrDefault(p => p.PluginTypeName == plugin); or not .FirstOrDefault(p => p.AssemblyPath.Split(Path.DirectorySeparatorChar).Last().Equals(plugin)); in FindPlugin implementation

How about with my recommendation? I wish it can be change in new version. Thanks.

Assembly scanning results in returning an entry per found plugin interface implementation, because of this, the same assembly is returned multiple times and thus loaded multiple times.
This results in a runtime error when executing any of the plugins from this assembly.

Proposed fix: let assembly scanning return 1 assembly per found plugin implementation type.

It's possible load plugins on runtime ?
I was thinking of a 'marketplace' where my customers can select and install the plugins without the need of restarting the app

Let me know if that is possible, thanks!

I think that to increase productivity and security we should instantiate DependaBot so that it can propose package updates.

This way we would have instant visibility of the updates to be done. 🚀

Hi I am looking for cross platform plugin systems for .net core and find yours, but trying the example with avalonia on OS X Mojave get the error "Unhandled exception. Prise.PrisePluginException: Platform is not supported"... so my question is, what is necesary to make osx supported?