protected override Expression VisitBlockHelperExpression(BlockHelperExpression bhex) { var isInlinePartial = bhex.HelperName == "#*inline"; var pathInfo = PathInfoStore.Current.GetOrAdd(bhex.HelperName); var bindingContext = CompilationContext.Args.BindingContext; var context = isInlinePartial ? bindingContext.As <object>() : bindingContext.Property(o => o.Value); var readerContext = bhex.Context; var direct = Compile(bhex.Body); var inverse = Compile(bhex.Inversion); var args = FunctionBinderHelpers.CreateArguments(bhex.Arguments, CompilationContext); var direction = bhex.IsRaw || pathInfo.IsBlockHelper ? BlockHelperDirection.Direct : BlockHelperDirection.Inverse; var blockParams = CreateBlockParams(); var blockHelpers = CompilationContext.Configuration.BlockHelpers; if (blockHelpers.TryGetValue(pathInfo, out var descriptor)) { return(BindByRef(pathInfo, descriptor)); } var helperResolvers = CompilationContext.Configuration.HelperResolvers; for (var index = 0; index < helperResolvers.Count; index++) { var resolver = helperResolvers[index]; if (!resolver.TryResolveBlockHelper(pathInfo, out var resolvedDescriptor)) { continue; } descriptor = new Ref <IHelperDescriptor <BlockHelperOptions> >(resolvedDescriptor); blockHelpers.AddOrReplace(pathInfo, descriptor); return(BindByRef(pathInfo, descriptor)); } var lateBindBlockHelperDescriptor = new LateBindBlockHelperDescriptor(pathInfo); var lateBindBlockHelperRef = new Ref <IHelperDescriptor <BlockHelperOptions> >(lateBindBlockHelperDescriptor); blockHelpers.AddOrReplace(pathInfo, lateBindBlockHelperRef); return(BindByRef(pathInfo, lateBindBlockHelperRef)); ExpressionContainer <ChainSegment[]> CreateBlockParams() { var parameters = bhex.BlockParams?.BlockParam?.Parameters; parameters ??= ArrayEx.Empty <ChainSegment>(); return(Arg(parameters)); } TemplateDelegate Compile(Expression expression) { var blockExpression = (BlockExpression)expression; return(FunctionBuilder.Compile(blockExpression.Expressions, new CompilationContext(CompilationContext))); } Expression BindByRef(PathInfo name, Ref <IHelperDescriptor <BlockHelperOptions> > helperBox) { var writer = CompilationContext.Args.EncodedWriter; var helperOptions = direction switch { BlockHelperDirection.Direct => New(() => new BlockHelperOptions(name, direct, inverse, blockParams, bindingContext)), BlockHelperDirection.Inverse => New(() => new BlockHelperOptions(name, inverse, direct, blockParams, bindingContext)), _ => throw new HandlebarsCompilerException("Helper referenced with unknown prefix", readerContext) }; var callContext = New(() => new Context(bindingContext, context)); return(Call(() => helperBox.Value.Invoke(writer, helperOptions, callContext, args))); } } }
protected override Expression VisitBlockHelperExpression(BlockHelperExpression bhex) { var isInlinePartial = bhex.HelperName == "#*inline"; var pathInfo = CompilationContext.Configuration.PathInfoStore.GetOrAdd(bhex.HelperName); var bindingContext = Arg <BindingContext>(CompilationContext.BindingContext); var context = isInlinePartial ? bindingContext.As <object>() : bindingContext.Property(o => o.Value); var readerContext = bhex.Context; var direct = Compile(bhex.Body); var inverse = Compile(bhex.Inversion); var arguments = CreateArguments(); var helperName = pathInfo.TrimmedPath; var direction = bhex.IsRaw || pathInfo.IsBlockHelper ? BlockHelperDirection.Direct : BlockHelperDirection.Inverse; var blockParams = CreateBlockParams(); var blockHelpers = CompilationContext.Configuration.BlockHelpers; if (blockHelpers.TryGetValue(pathInfo, out var descriptor)) { return(BindByRef(descriptor)); } var helperResolvers = CompilationContext.Configuration.HelperResolvers; for (var index = 0; index < helperResolvers.Count; index++) { var resolver = helperResolvers[index]; if (!resolver.TryResolveBlockHelper(helperName, out var resolvedDescriptor)) { continue; } return(Bind(resolvedDescriptor)); } var lateBindBlockHelperDescriptor = new LateBindBlockHelperDescriptor(pathInfo, CompilationContext.Configuration); var lateBindBlockHelperRef = new StrongBox <BlockHelperDescriptorBase>(lateBindBlockHelperDescriptor); blockHelpers.Add(pathInfo, lateBindBlockHelperRef); return(BindByRef(lateBindBlockHelperRef)); ExpressionContainer <ChainSegment[]> CreateBlockParams() { var parameters = bhex.BlockParams?.BlockParam?.Parameters; if (parameters == null) { parameters = ArrayEx.Empty <ChainSegment>(); } return(Arg(parameters)); } ExpressionContainer <object[]> CreateArguments() { var args = bhex.Arguments .ApplyOn((PathExpression pex) => pex.Context = PathExpression.ResolutionContext.Parameter) .Select(o => FunctionBuilder.Reduce(o, CompilationContext)); return(Array <object>(args)); } Action <BindingContext, TextWriter, object> Compile(Expression expression) { var blockExpression = (BlockExpression)expression; return(FunctionBuilder.CompileCore(blockExpression.Expressions, CompilationContext.Configuration)); } Expression BindByRef(StrongBox <BlockHelperDescriptorBase> value) { return(direction switch { BlockHelperDirection.Direct => Call(() => BlockHelperCallBindingByRef(bindingContext, context, blockParams, direct, inverse, arguments, value)), BlockHelperDirection.Inverse => Call(() => BlockHelperCallBindingByRef(bindingContext, context, blockParams, inverse, direct, arguments, value)), _ => throw new HandlebarsCompilerException("Helper referenced with unknown prefix", readerContext) });