aspnetcore/src/Microsoft.AspNetCore.Mvc.Ra.../ModelExpressionPass.cs

86 lines
3.4 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.AspNetCore.Razor.Language;
using Microsoft.AspNetCore.Razor.Language.Intermediate;
namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
{
public class ModelExpressionPass : IntermediateNodePassBase, IRazorOptimizationPass
{
private const string ModelExpressionTypeName = "Microsoft.AspNetCore.Mvc.ViewFeatures.ModelExpression";
protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
{
var visitor = new Visitor();
visitor.Visit(documentNode);
}
private class Visitor : IntermediateNodeWalker
{
public List<TagHelperIntermediateNode> TagHelpers { get; } = new List<TagHelperIntermediateNode>();
public override void VisitTagHelperProperty(TagHelperPropertyIntermediateNode node)
{
if (string.Equals(node.BoundAttribute.TypeName, ModelExpressionTypeName, StringComparison.Ordinal) ||
(node.IsIndexerNameMatch &&
string.Equals(node.BoundAttribute.IndexerTypeName, ModelExpressionTypeName, StringComparison.Ordinal)))
{
var expression = new CSharpExpressionIntermediateNode();
expression.Children.Add(new IntermediateToken()
{
Kind = TokenKind.CSharp,
Content = "ModelExpressionProvider.CreateModelExpression(ViewData, __model => ",
});
if (node.Children.Count == 1 && node.Children[0] is IntermediateToken token && token.IsCSharp)
{
// A 'simple' expression will look like __model => __model.Foo
expression.Children.Add(new IntermediateToken()
{
Kind = TokenKind.CSharp,
Content = "__model."
});
expression.Children.Add(token);
}
else
{
for (var i = 0; i < node.Children.Count; i++)
{
if (node.Children[i] is CSharpExpressionIntermediateNode nestedExpression)
{
for (var j = 0; j < nestedExpression.Children.Count; j++)
{
if (nestedExpression.Children[j] is IntermediateToken cSharpToken &&
cSharpToken.IsCSharp)
{
expression.Children.Add(cSharpToken);
}
}
continue;
}
}
}
expression.Children.Add(new IntermediateToken()
{
Kind = TokenKind.CSharp,
Content = ")",
});
node.Children.Clear();
node.Children.Add(expression);
}
}
}
}
}