public override void ConvertToJavascript(JavascriptConversionContext context)
{
var methodCall = context.Node as MethodCallExpression;
if (methodCall != null)
{
if (methodCall.Method.DeclaringType == typeof(string))
{
switch (methodCall.Method.Name)
{
case "Concat":
{
context.PreventDefault();
var writer = context.GetWriter();
using (writer.Operation(JavascriptOperationTypes.Concat))
{
if (methodCall.Arguments.Count == 0)
{
writer.Write("''");
}
else
{
if (GetTypeOfExpression(methodCall.Arguments[0]) != typeof(string))
{
writer.Write("''+");
}
context.WriteMany('+', methodCall.Arguments);
}
}
return;
}
case "Join":
{
context.PreventDefault();
var writer = context.GetWriter();
using (writer.Operation(JavascriptOperationTypes.Call))
{
using (writer.Operation(JavascriptOperationTypes.IndexerProperty))
{
var pars = methodCall.Method.GetParameters();
if (pars.Length == 4 && pars[1].ParameterType.IsArray && pars[2].ParameterType == typeof(int) && pars[3].ParameterType == typeof(int))
{
throw new NotSupportedException("The `String.Join` method with start and count paramaters is not supported.");
}
if (pars.Length != 2 || !TypeHelpers.IsEnumerableType(pars[1].ParameterType))
{
throw new NotSupportedException("This `String.Join` method is not supported.");
}
// if second parameter is an enumerable, render it directly
context.Visitor.Visit(methodCall.Arguments[1]);
writer.Write(".join");
}
writer.Write('(');
// separator
using (writer.Operation(0))
context.Visitor.Visit(methodCall.Arguments[0]);
writer.Write(')');
}
return;
}
}
}
}
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (node.Method.IsSpecialName)
{
var isIndexer = node.Method.Name == "get_Item" || node.Method.Name == "get_Chars";
if (isIndexer)
{
using (this.result.Operation(JavascriptOperationTypes.IndexerProperty))
{
this.Visit(node.Object);
this.result.Write('[');
using (this.result.Operation(0))
{
var posStart0 = this.result.Length;
foreach (var arg in node.Arguments)
{
if (this.result.Length != posStart0)
{
this.result.Write(',');
}
this.Visit(arg);
}
}
this.result.Write(']');
return(node);
}
}
if (node.Method.Name == "set_Item")
{
using (this.result.Operation(0))
{
using (this.result.Operation(JavascriptOperationTypes.AssignRhs))
{
using (this.result.Operation(JavascriptOperationTypes.IndexerProperty))
{
this.Visit(node.Object);
this.result.Write('[');
using (this.result.Operation(0))
{
var posStart0 = this.result.Length;
foreach (var arg in node.Arguments)
{
if (this.result.Length != posStart0)
{
this.result.Write(',');
}
this.Visit(arg);
}
}
this.result.Write(']');
}
}
this.result.Write('=');
this.Visit(node.Arguments.Single());
}
return(node);
}
}
else
{
if (node.Method.DeclaringType != null &&
(node.Method.Name == "ContainsKey" &&
TypeHelpers.IsDictionaryType(node.Method.DeclaringType)))
{
using (this.result.Operation(JavascriptOperationTypes.Call))
{
using (this.result.Operation(JavascriptOperationTypes.IndexerProperty))
this.Visit(node.Object);
this.result.Write(".hasOwnProperty(");
using (this.result.Operation(0))
this.Visit(node.Arguments.Single());
this.result.Write(')');
return(node);
}
}
}
if (node.Method.DeclaringType == typeof(string))
{
if (node.Method.Name == "Contains")
{
using (this.result.Operation(JavascriptOperationTypes.Comparison))
{
using (this.result.Operation(JavascriptOperationTypes.Call))
{
using (this.result.Operation(JavascriptOperationTypes.IndexerProperty))
this.Visit(node.Object);
this.result.Write(".indexOf(");
using (this.result.Operation(0))
{
var posStart = this.result.Length;
foreach (var arg in node.Arguments)
{
if (this.result.Length > posStart)
{
this.result.Write(',');
}
this.Visit(arg);
}
}
this.result.Write(')');
}
this.result.Write(">=0");
return(node);
}
}
}
if (node.Method.Name == "ToString" && node.Type == typeof(string) && node.Object != null)
{
string methodName = null;
if (node.Arguments.Count == 0 || typeof(IFormatProvider).IsAssignableFrom(node.Arguments[0].Type))
{
methodName = "toString()";
}
else if (TypeHelpers.IsNumericType(node.Object.Type) &&
node.Arguments.Count >= 1 &&
node.Arguments[0].Type == typeof(string) &&
node.Arguments[0].NodeType == ExpressionType.Constant)
{
var str = (string)((ConstantExpression)node.Arguments[0]).Value;
var match = Regex.Match(str, @"^([DEFGNX])(\d*)$", RegexOptions.IgnoreCase);
var f = match.Groups[1].Value.ToUpper();
var n = match.Groups[2].Value;
if (f == "D")
{
methodName = "toString()";
}
else if (f == "E")
{
methodName = "toExponential(" + n + ")";
}
else if (f == "F" || f == "G")
{
methodName = "toFixed(" + n + ")";
}
else if (f == "N")
{
methodName = "toLocaleString()";
}
else if (f == "X")
{
methodName = "toString(16)";
}
}
if (methodName != null)
{
using (this.result.Operation(JavascriptOperationTypes.Call))
{
using (this.result.Operation(JavascriptOperationTypes.IndexerProperty))
this.Visit(node.Object);
this.result.WriteFormat(".{0}", methodName);
return(node);
}
}
}
if (!node.Method.IsStatic)
{
throw new NotSupportedException(string.Format("By default, Lambda2Js cannot convert custom instance methods, only static ones. `{0}` is not static.", node.Method.Name));
}
using (this.result.Operation(JavascriptOperationTypes.Call))
if (node.Method.DeclaringType != null)
{
this.result.Write(node.Method.DeclaringType.FullName);
this.result.Write('.');
this.result.Write(node.Method.Name);
this.result.Write('(');
var posStart = this.result.Length;
using (this.result.Operation(0))
foreach (var arg in node.Arguments)
{
if (this.result.Length != posStart)
{
this.result.Write(',');
}
this.Visit(arg);
}
this.result.Write(')');
return(node);
}
return(node);
}
protected override Expression VisitListInit(ListInitExpression node)
{
// Detecting a new dictionary
if (TypeHelpers.IsDictionaryType(node.Type))
{
using (this.result.Operation(0))
{
this.result.Write('{');
var posStart = this.result.Length;
foreach (var init in node.Initializers)
{
if (this.result.Length > posStart)
{
this.result.Write(',');
}
if (init.Arguments.Count != 2)
{
throw new NotSupportedException(
"Objects can only be initialized with methods that receive pairs: key -> name");
}
var nameArg = init.Arguments[0];
if (nameArg.NodeType != ExpressionType.Constant || nameArg.Type != typeof(string))
{
throw new NotSupportedException("The key of an object must be a constant string value");
}
var name = (string)((ConstantExpression)nameArg).Value;
if (Regex.IsMatch(name, @"^\w[\d\w]*$"))
{
this.result.Write(name);
}
else
{
this.WriteStringLiteral(name);
}
this.result.Write(':');
this.Visit(init.Arguments[1]);
}
this.result.Write('}');
}
return(node);
}
// Detecting a new dictionary
if (TypeHelpers.IsListType(node.Type))
{
using (this.result.Operation(0))
{
this.result.Write('[');
var posStart = this.result.Length;
foreach (var init in node.Initializers)
{
if (this.result.Length > posStart)
{
this.result.Write(',');
}
if (init.Arguments.Count != 1)
{
throw new Exception(
"Arrays can only be initialized with methods that receive a single parameter for the value");
}
this.Visit(init.Arguments[0]);
}
this.result.Write(']');
}
return(node);
}
return(node);
}
protected override Expression VisitMember(MemberExpression node)
{
if (node.Expression == null)
{
var decl = node.Member.DeclaringType;
if (decl == typeof(string))
{
if (node.Member.Name == "Empty")
{
using (this.result.Operation(JavascriptOperationTypes.Literal))
this.result.Write("\"\"");
return(node);
}
}
}
using (this.result.Operation(node))
{
var metadataProvider = this.Options.GetMetadataProvider();
var pos = this.result.Length;
if (node.Expression == null)
{
var decl = node.Member.DeclaringType;
if (decl != null)
{
// TODO: there should be a way to customize the name of types through metadata
this.result.Write(decl.FullName);
this.result.Write('.');
this.result.Write(decl.Name);
}
}
else if (node.Expression != this.contextParameter)
{
this.Visit(node.Expression);
}
else
{
this.usedScopeMembers = this.usedScopeMembers ?? new List <string>();
var meta = metadataProvider.GetMemberMetadata(node.Member);
Debug.Assert(!string.IsNullOrEmpty(meta?.MemberName), "!string.IsNullOrEmpty(meta?.MemberName)");
this.usedScopeMembers.Add(meta?.MemberName ?? node.Member.Name);
}
if (this.result.Length > pos)
{
this.result.Write('.');
}
var propInfo = node.Member as PropertyInfo;
if (propInfo?.DeclaringType != null &&
node.Type == typeof(int) &&
node.Member.Name == "Count" &&
TypeHelpers.IsListType(propInfo.DeclaringType))
{
this.result.Write("length");
}
else
{
var meta = metadataProvider.GetMemberMetadata(node.Member);
Debug.Assert(!string.IsNullOrEmpty(meta?.MemberName), "!string.IsNullOrEmpty(meta?.MemberName)");
this.result.Write(meta?.MemberName);
}
return(node);
}
}
public override void ConvertToJavascript(JavascriptConversionContext context)
{
var methodCall = context.Node as MethodCallExpression;
if (methodCall != null)
{
if (methodCall.Method.DeclaringType == typeof(Math))
{
NameLength jsInfo;
if (membersMap.TryGetValue(methodCall.Method.Name, out jsInfo))
{
if (methodCall.Arguments.Count == jsInfo.length)
{
using (context.Operation(JavascriptOperationTypes.Call))
{
using (context.Operation(JavascriptOperationTypes.IndexerProperty))
context.Write("Math." + jsInfo.name);
context.WriteManyIsolated('(', ')', ',', methodCall.Arguments);
}
return;
}
else if (methodCall.Method.Name == "Log" &&
methodCall.Arguments.Count == 2)
{
// JavaScript does not support `Math.log` with 2 parameters,
// But it is easy enough for us to give a little help!
using (context.Operation(JavascriptOperationTypes.MulDivMod))
{
using (context.Operation(JavascriptOperationTypes.Call))
{
using (context.Operation(JavascriptOperationTypes.IndexerProperty))
context.Write("Math.log");
context.Write('(');
using (context.Operation(0))
context.Write(methodCall.Arguments[0]);
context.Write(')');
}
context.Write('/');
using (context.Operation(JavascriptOperationTypes.Call))
{
using (context.Operation(JavascriptOperationTypes.IndexerProperty))
context.Write("Math.log");
context.Write('(');
using (context.Operation(0))
context.Write(methodCall.Arguments[1]);
context.Write(')');
}
}
return;
}
else if (methodCall.Method.Name == "Round" &&
methodCall.Arguments.Count == 2 &&
TypeHelpers.IsNumericType(methodCall.Arguments[1].Type))
{
// We won't support `Math.Round` with two parameters by default.
// To do it, we'd have to repeat an input value in the expression (unacceptable):
// Math.Round(A, B) => Math.round(A * Math.pow(10, B)) / Math.pow(10, B)
// Or start helping with hacky things (acceptable, but not by default):
// Math.Round(A, B) => (function(a, b) { return Math.round(a * b) / b; })(A, Math.pow(10, B));
if (this.round2)
{
using (context.Operation(JavascriptOperationTypes.Call))
{
context.WriteLambda <Func <double, double, double> >((a, b) => Math.Round(a * b) / b);
context.Write('(');
using (context.Operation(0))
context.Write(methodCall.Arguments[0]);
context.Write(',');
using (context.Operation(0))
using (context.Operation(JavascriptOperationTypes.Call))
{
using (context.Operation(JavascriptOperationTypes.IndexerProperty))
context.Write("Math.pow");
context.Write('(');
context.Write("10");
context.Write(',');
using (context.Operation(0))
context.Write(methodCall.Arguments[1]);
context.Write(')');
}
context.Write(')');
return;
}
}
}
}
}
}
// E and PI are constant values, they will never result in
// a member access expression. We will have to catch the
// exact numbers, and convert them instead.
var constVal = context.Node as ConstantExpression;
if (constVal != null)
{
if (constVal.Value.Equals(Math.E))
{
using (context.Operation(JavascriptOperationTypes.IndexerProperty))
context.Write("Math.E");
}
else if (constVal.Value.Equals(Math.PI))
{
using (context.Operation(JavascriptOperationTypes.IndexerProperty))
context.Write("Math.PI");
}
}
}