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MediatR Source Generator
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| using System.Diagnostics; | |
| using System.Linq; | |
| using System.Text; | |
| using Microsoft.CodeAnalysis; | |
| using Microsoft.CodeAnalysis.CSharp.Syntax; | |
| using Microsoft.CodeAnalysis.Text; | |
| namespace MediatorGenerator | |
| { | |
| [Generator] | |
| public sealed class SourceGenerator : ISourceGenerator | |
| { | |
| public void Initialize(GeneratorInitializationContext context) | |
| { | |
| #if DEBUG | |
| if (!Debugger.IsAttached) | |
| { | |
| Debugger.Launch(); | |
| } | |
| #endif | |
| } | |
| public void Execute(GeneratorExecutionContext context) | |
| { | |
| var sourceBuilder = new StringBuilder(@" | |
| using System; | |
| namespace HelloWorldGenerated | |
| { | |
| public static class HelloWorld | |
| { | |
| public static void SayHello() | |
| { | |
| Console.WriteLine(""Hello from generated code!""); | |
| Console.WriteLine(""The following syntax trees existed in the compilation that created this program:""); | |
| "); | |
| // using the context, get a list of syntax trees in the users compilation | |
| var syntaxTrees = context.Compilation.SyntaxTrees; | |
| var commands = syntaxTrees.Where(x => x.GetText().ToString().Contains("Command")); | |
| var commandSourceBuilder = new StringBuilder(); | |
| foreach (var command in commands) | |
| { | |
| var usingDirectives = command.GetRoot().DescendantNodes().OfType<UsingDirectiveSyntax>(); | |
| var usingDirectivesAsText = string.Join("\r\n", usingDirectives); | |
| commandSourceBuilder.Append(usingDirectivesAsText); | |
| var classDeclarationSyntax = | |
| command.GetRoot().DescendantNodes().OfType<ClassDeclarationSyntax>().First(); | |
| var className = classDeclarationSyntax.Identifier.ToString(); | |
| var generatedClassName = $"{className}Handler"; | |
| var splitClass = classDeclarationSyntax.ToString().Split(new[] {'{'}, 2); | |
| commandSourceBuilder.Append($@" | |
| namespace GeneratedCommandHandler | |
| {{ | |
| public class {generatedClassName} : IRequestHandler<{className}, ApplicationUserResult> | |
| {{ | |
| public {generatedClassName}() | |
| {{ | |
| }} | |
| public async Task<ApplicationUserResult> Handle({className} request, CancellationToken cancellationToken) | |
| {{ | |
| }} | |
| }} | |
| }} | |
| "); | |
| } | |
| // add the filepath of each tree to the class we're building | |
| // foreach (SyntaxTree tree in syntaxTrees) | |
| // { | |
| // sourceBuilder.AppendLine($@"Console.WriteLine(@"" - {tree.FilePath}"");"); | |
| // } | |
| // | |
| // finish creating the source to inject | |
| // sourceBuilder.Append(@" | |
| // } | |
| // } | |
| // }"); | |
| // inject the created source into the users compilation | |
| context.AddSource("helloWorldGenerator", SourceText.From(commandSourceBuilder.ToString(), Encoding.UTF8)); | |
| } | |
| } | |
| } |
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