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Support for List, Nested Object and Dictionary property initializers #30

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85 changes: 84 additions & 1 deletion Lambda2Js.Tests/CustomClassMethodTests.cs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Newtonsoft.Json;
Expand Down Expand Up @@ -36,9 +37,20 @@ public static int GetValue(int x)

[JsonProperty(PropertyName = "otherName2")]
public string Custom2 { get; set; }

[JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
public string Custom3 { get; set; }

public Dictionary<string, object> Dictionary { get; set; }

public List<string> List { get; set; }

public NestedThing Nested { get; set; }
}

public class NestedThing
{
public string Name { get; set; }
}

public class MyCustomClassMethods : JavascriptConversionExtension
Expand Down Expand Up @@ -150,6 +162,77 @@ public void NewCustomClassAsNewOfTypeWithMemberInit()
Assert.IsInstanceOfType(exception, typeof(NotSupportedException), "Exception not thrown.");
}

[TestMethod]
public void NewCustomClassWithNestedThingInit()
{
Expression<Func<MyCustomClass>> expr = () => new MyCustomClass { Name = "Miguel", Nested = { Name = "Nested" } };

var js = expr.Body.CompileToJavascript(
new JavascriptCompilationOptions(
new MemberInitAsJson(typeof(MyCustomClass))));

Assert.AreEqual("{Name:\"Miguel\",Nested:{Name:\"Nested\"}}", js);
}

[TestMethod]
public void NewCustomClassWithNestedThingConstructorFailsWithDisallowedTypeInit()
{
Expression<Func<MyCustomClass>> expr = () => new MyCustomClass { Name = "Miguel", Nested = new NestedThing { Name = "Nested" } };

Exception exception = null;
try
{
expr.Body.CompileToJavascript(
new JavascriptCompilationOptions(
new MemberInitAsJson(typeof(MyCustomClass))));
}
catch (Exception ex)
{
exception = ex;
}

Assert.IsInstanceOfType(exception, typeof(NotSupportedException), "Exception not thrown.");
}

[TestMethod]
public void NewCustomClassWithNestedThingConstructorInit()
{
Expression<Func<MyCustomClass>> expr = () => new MyCustomClass { Name = "Miguel", Nested = new NestedThing { Name = "Nested" } };

var js = expr.Body.CompileToJavascript(
new JavascriptCompilationOptions(
new MemberInitAsJson(typeof(MyCustomClass), typeof(NestedThing))));

Assert.AreEqual("{Name:\"Miguel\",Nested:{Name:\"Nested\"}}", js);
}

[TestMethod]
public void NewCustomClassWithListInit()
{
Expression<Func<MyCustomClass>> expr = () => new MyCustomClass { Name = "Miguel", List = { "One", "Two" } };

var js = expr.Body.CompileToJavascript(
new JavascriptCompilationOptions(
new MemberInitAsJson(typeof(MyCustomClass))));

Assert.AreEqual("{Name:\"Miguel\",List:[\"One\",\"Two\"]}", js);
}

//This Dictionary constructor is only present for netstandard 2.0 or later (netcoreapp2.0 tests, not netcoreapp1.0)
#if !NETCOREAPP1_1
[TestMethod]
public void NewCustomClassWithDictionaryFromListConstructorInit()
{
Expression<Func<MyCustomClass>> expr = () => new MyCustomClass
{ Name = "Miguel", Dictionary = new Dictionary<string, object>(new[] { new KeyValuePair<string, object>("One", 1), new KeyValuePair<string, object>("Two", 2) }) };

var js = expr.Body.CompileToJavascript(
new JavascriptCompilationOptions(MemberInitAsJson.ForAllTypes));

Assert.AreEqual("{Name:\"Miguel\",Dictionary:{\"One\":1,\"Two\":2}}", js);
}
#endif

[TestMethod]
public void CustomMetadata1()
{
Expand Down
144 changes: 123 additions & 21 deletions Lambda2Js/Plugins/MemberInitAsJson.cs
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Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,9 @@
using System;
using System.Collections;
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text.RegularExpressions;
using JetBrains.Annotations;

Expand Down Expand Up @@ -51,19 +53,22 @@ public MemberInitAsJson([NotNull] Predicate<Type> typePredicate)
this.TypePredicate = typePredicate;
}

private bool IsAcceptableType(Type type)
{
var typeOk1 = NewObjectTypes?.Contains(type) ?? false;
var typeOk2 = TypePredicate?.Invoke(type) ?? false;
var typeOk3 = NewObjectTypes == null && TypePredicate == null;

return typeOk1 || typeOk2 || typeOk3;
}

public override void ConvertToJavascript(JavascriptConversionContext context)
{
var initExpr = context.Node as MemberInitExpression;
if (initExpr == null)
return;
var typeOk1 = this.NewObjectTypes?.Contains(initExpr.Type) ?? false;
var typeOk2 = this.TypePredicate?.Invoke(initExpr.Type) ?? false;
var typeOk3 = this.NewObjectTypes == null && this.TypePredicate == null;
if (!typeOk1 && !typeOk2 && !typeOk3)
return;
if (initExpr.NewExpression.Arguments.Count > 0)
return;
if (initExpr.Bindings.Any(mb => mb.BindingType != MemberBindingType.Assignment))

if (!IsAcceptableType(initExpr.Type))
return;

context.PreventDefault();
Expand All @@ -72,26 +77,123 @@ public override void ConvertToJavascript(JavascriptConversionContext context)
{
writer.Write('{');

var posStart = writer.Length;
foreach (var assignExpr in initExpr.Bindings.Cast<MemberAssignment>())
foreach (var binding in initExpr.Bindings)
{
if (writer.Length > posStart)
if(binding != initExpr.Bindings[0])
writer.Write(',');

var metadataProvider = context.Options.GetMetadataProvider();
var meta = metadataProvider.GetMemberMetadata(assignExpr.Member);
var memberName = meta?.MemberName;
Debug.Assert(!string.IsNullOrEmpty(memberName), "!string.IsNullOrEmpty(memberName)");
if (Regex.IsMatch(memberName, @"^\w[\d\w]*$"))
writer.Write(memberName);
WriteBinding(context, binding, writer);
}

writer.Write('}');
}
}

/// <summary>
/// Recursively callable WriteBinding() for MemberMemberBinding case
/// </summary>
/// <param name="context"></param>
/// <param name="binding"></param>
/// <param name="writer"></param>
/// <exception cref="InvalidOperationException"></exception>
/// <exception cref="NotImplementedException"></exception>
/// <exception cref="NotSupportedException"></exception>
private void WriteBinding(JavascriptConversionContext context, MemberBinding binding, JavascriptWriter writer)
{
var metadataProvider = context.Options.GetMetadataProvider();
var meta = metadataProvider.GetMemberMetadata(binding.Member);
var memberName = meta?.MemberName;
Debug.Assert(!string.IsNullOrEmpty(memberName), "!string.IsNullOrEmpty(memberName)");
if (Regex.IsMatch(memberName, @"^\w[\d\w]*$"))
writer.Write(memberName);
else
writer.WriteLiteral(memberName);

writer.Write(':');

if (binding is MemberAssignment ma)
{
if (ma.Expression is NewExpression ne)
{
if(!IsAcceptableType(ne.Type))
throw new InvalidOperationException($"Unable to initialize type: {ne.Type.FullName}");

if (typeof(IDictionary).GetTypeInfo().IsAssignableFrom(ne.Type.GetTypeInfo()))
{
writer.Write('{');

//Expressions don't support dictionary initializer syntax, so...
//Handle Dictionary(IEnumerable<KVP>) constructor - new Dictionary<string, Thing>(new[] { new KeyValuePair<string, Thing>("One", new Thing { Name = "Fred" }) })
if (ne.Arguments.Count == 1 && ne.Arguments[0] is NewArrayExpression nae)
{
foreach (var nie in nae.Expressions)
{
if (nie is NewExpression newItem)
{
//Get KVP constructor args for Key and Value
var key = newItem.Arguments[0];
var value = newItem.Arguments[1];
if(nie != nae.Expressions[0])
writer.Write(',');
context.Visitor.Visit(key);
writer.Write(':');
context.Visitor.Visit(value);
}
else
{
throw new NotSupportedException($"Not supported for Dictionary item expression: {nie}");
}
}
}
else
{
throw new NotSupportedException($"Not supported for Dictionary constructor with {ne.Arguments.Count} arguments: {ne}");
}

writer.Write('}');
}
else
writer.WriteLiteral(memberName);
{
throw new NotSupportedException($"Not supported for non-dictionary constructor: {ne}");
}

}
else
{
context.Visitor.Visit(ma.Expression);
}

}
else if (binding is MemberMemberBinding mmb)
{
//Nested object initializers: new Thing{ Nested = new NestedThing { Name="Fred" } }
writer.Write('{');
foreach (var mb in mmb.Bindings)
{
if (mb != mmb.Bindings[0])
writer.Write(',');
WriteBinding(context, mb, writer);
}
writer.Write('}');
}
else if (binding is MemberListBinding mlb)
{
//List binding

writer.Write('[');

writer.Write(':');
context.Visitor.Visit(assignExpr.Expression);
foreach (var initializer in mlb.Initializers)
{
if (initializer != mlb.Initializers[0])
writer.Write(",");
context.Visitor.Visit(initializer.Arguments[0]);
}

writer.Write('}');
writer.Write(']');
}
else
{
throw new NotSupportedException($"Unsupported: {binding.Member.Name} - {binding.BindingType} ({binding.GetType().FullName})");
}
}
}
Expand Down