Merge pull request #22 from bonsai-rx/type-matching

Generate type matching operator for derived types
bonsai-rx · Jan 12, 2024 · 278a0b9 · 278a0b9
2 parents 8563ebe + 0debad8
commit 278a0b9
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Showing 3 changed files with 123 additions and 6 deletions.
diff --git a/Bonsai.Sgen/CSharpClassCodeArtifact.cs b/Bonsai.Sgen/CSharpClassCodeArtifact.cs
@@ -0,0 +1,20 @@
+using NJsonSchema.CodeGeneration;
+
+namespace Bonsai.Sgen
+{
+    internal class CSharpClassCodeArtifact : CodeArtifact
+    {
+        public CSharpClassCodeArtifact(CSharpClassTemplateModel model, ITemplate template) : base(
+            model.ClassName,
+            model.BaseClassName,
+            CodeArtifactType.Class,
+            CodeArtifactLanguage.CSharp,
+            CodeArtifactCategory.Contract,
+            template)
+        {
+            Model = model;
+        }
+
+        public CSharpClassTemplateModel Model { get; }
+    }
+}
diff --git a/Bonsai.Sgen/CSharpCodeDomGenerator.cs b/Bonsai.Sgen/CSharpCodeDomGenerator.cs
@@ -52,7 +52,7 @@ private CodeArtifact GenerateClass(JsonSchema schema, string typeName)
         {
             var model = new CSharpClassTemplateModel(typeName, Settings, _resolver, schema, RootObject);
             var template = new CSharpClassTemplate(model, _provider, _options, Settings);
-            return new CodeArtifact(typeName, model.BaseClassName, CodeArtifactType.Class, CodeArtifactLanguage.CSharp, CodeArtifactCategory.Contract, template);
+            return new CSharpClassCodeArtifact(model, template);
         }
 
         private CodeArtifact GenerateClass(CSharpCodeDomTemplate template)
@@ -83,10 +83,16 @@ public override IEnumerable<CodeArtifact> GenerateTypes()
             var types = base.GenerateTypes();
             var extraTypes = new List<CodeArtifact>();
             var schema = (JsonSchema)RootObject;
-            var classTypes = types
-                .Where(type => type.Type == CodeArtifactType.Class)
-                .ExceptBy(new[] { nameof(JsonInheritanceAttribute), nameof(JsonInheritanceConverter) }, r => r.TypeName)
-                .ToList();
+            var classTypes = (from type in types
+                              let classType = type as CSharpClassCodeArtifact
+                              where classType != null
+                              select classType).ToList();
+            var discriminatorTypes = classTypes.Where(modelType => modelType.Model.HasDiscriminator).ToList();
+            foreach (var type in discriminatorTypes)
+            {
+                var matchTemplate = new CSharpTypeMatchTemplate(type, _provider, _options, Settings);
+                extraTypes.Add(GenerateClass(matchTemplate));
+            }
             if (Settings.SerializerLibraries.HasFlag(SerializerLibraries.NewtonsoftJson))
             {
                 var serializer = new CSharpJsonSerializerTemplate(classTypes, _provider, _options, Settings);
@@ -96,7 +102,6 @@ public override IEnumerable<CodeArtifact> GenerateTypes()
             }
             if (Settings.SerializerLibraries.HasFlag(SerializerLibraries.YamlDotNet))
             {
-                var discriminatorTypes = classTypes.Where(modelType => modelType.Code.Contains("YamlDiscriminator")).ToList();
                 if (discriminatorTypes.Count > 0)
                 {
                     var discriminator = new CSharpYamlDiscriminatorTemplate(_provider, _options, Settings);

diff --git a/Bonsai.Sgen/CSharpTypeMatchTemplate.cs b/Bonsai.Sgen/CSharpTypeMatchTemplate.cs
@@ -0,0 +1,92 @@
+using System.CodeDom;
+using System.CodeDom.Compiler;
+using System.ComponentModel;
+using System.Xml.Serialization;
+
+namespace Bonsai.Sgen
+{
+    internal class CSharpTypeMatchTemplate : CSharpCodeDomTemplate
+    {
+        public CSharpTypeMatchTemplate(
+            CSharpClassCodeArtifact modelType,
+            CodeDomProvider provider,
+            CodeGeneratorOptions options,
+            CSharpCodeDomGeneratorSettings settings)
+            : base(provider, options, settings)
+        {
+            ModelType = modelType;
+        }
+
+        public CSharpClassCodeArtifact ModelType { get; }
+
+        public override string TypeName => $"Match{ModelType.TypeName}";
+
+        public override void BuildType(CodeTypeDeclaration type)
+        {
+            type.BaseTypes.Add(new CodeTypeReference("Bonsai.Expressions.SingleArgumentExpressionBuilder"));
+            type.CustomAttributes.Add(new CodeAttributeDeclaration(
+                new CodeTypeReference(typeof(DefaultPropertyAttribute)),
+                new CodeAttributeArgument(new CodePrimitiveExpression("Type"))));
+            type.CustomAttributes.Add(new CodeAttributeDeclaration(
+                new CodeTypeReference("Bonsai.WorkflowElementCategoryAttribute"),
+                new CodeAttributeArgument(new CodeFieldReferenceExpression(
+                    new CodeTypeReferenceExpression("Bonsai.ElementCategory"),
+                    "Combinator"))));
+            foreach (var modelType in ModelType.Model.DerivedClasses)
+            {
+                type.CustomAttributes.Add(new CodeAttributeDeclaration(
+                    new CodeTypeReference(typeof(XmlIncludeAttribute)),
+                    new CodeAttributeArgument(new CodeTypeOfExpression(
+                        new CodeTypeReference(
+                            "Bonsai.Expressions.TypeMapping",
+                            new CodeTypeReference(modelType.ClassName))))));
+            }
+
+            type.Members.Add(new CodeSnippetTypeMember(
+@$"    public Bonsai.Expressions.TypeMapping Type {{ get; set; }}
+
+    public override System.Linq.Expressions.Expression Build(System.Collections.Generic.IEnumerable<System.Linq.Expressions.Expression> arguments)
+    {{
+        var typeMapping = Type;
+        var returnType = typeMapping != null ? typeMapping.GetType().GetGenericArguments()[0] : typeof({ModelType.TypeName});
+        return System.Linq.Expressions.Expression.Call(
+            typeof({TypeName}),
+            ""Process"",
+            new System.Type[] {{ returnType }},
+            System.Linq.Enumerable.Single(arguments));
+    }}
+"));
+            var sourceTypeReference = new CodeTypeReference(ModelType.TypeName);
+            var genericTypeParameter = new CodeTypeParameter("TResult") { Constraints = { sourceTypeReference } };
+            var sourceParameter = new CodeParameterDeclarationExpression(
+                new CodeTypeReference(typeof(IObservable<>)) { TypeArguments = { sourceTypeReference } }, "source");
+            type.Members.Add(new CodeMemberMethod
+            {
+                Name = "Process",
+                Attributes = MemberAttributes.Private | MemberAttributes.Static,
+                TypeParameters = { genericTypeParameter },
+                Parameters = { sourceParameter },
+                ReturnType = new CodeTypeReference(typeof(IObservable<>))
+                {
+                    TypeArguments = { new CodeTypeReference(genericTypeParameter) }
+                },
+                Statements =
+                {
+                    new CodeExpressionStatement(new CodeSnippetExpression(
+@$"return System.Reactive.Linq.Observable.Create<{genericTypeParameter.Name}>(observer =>
+        {{
+            var sourceObserver = System.Reactive.Observer.Create<{ModelType.TypeName}>(
+                value =>
+                {{
+                    var match = value as {genericTypeParameter.Name};
+                    if (match != null) observer.OnNext(match);
+                }},
+                observer.OnError,
+                observer.OnCompleted);
+            return System.ObservableExtensions.SubscribeSafe(source, sourceObserver);
+        }})"))
+                }
+            });
+        }
+    }
+}