protected override Expression VisitIteratorExpression(IteratorExpression iex)
{
var context = ExpressionShortcuts.Arg <BindingContext>(CompilationContext.BindingContext);
var sequence = ExpressionShortcuts.Var <object>("sequence");
var template = FunctionBuilder.CompileCore(new[] { iex.Template }, CompilationContext.Configuration);
var ifEmpty = FunctionBuilder.CompileCore(new[] { iex.IfEmpty }, CompilationContext.Configuration);
var compiledSequence = ExpressionShortcuts.Arg <object>(FunctionBuilder.Reduce(iex.Sequence, CompilationContext));
var blockParams = ExpressionShortcuts.Arg <BlockParam>(iex.BlockParams);
var blockParamsProvider = ExpressionShortcuts.Call(() => BlockParamsValueProvider.Create(context, blockParams));
var blockParamsProviderVar = ExpressionShortcuts.Var <BlockParamsValueProvider>();
return(ExpressionShortcuts.Block()
.Parameter(sequence, compiledSequence)
.Parameter(blockParamsProviderVar, blockParamsProvider)
.Line(blockParamsProviderVar.Using((self, builder) =>
{
builder
.Line(context.Call(o => o.RegisterValueProvider((IValueProvider)self)))
.Line(ExpressionShortcuts.Try()
.Body(ExpressionShortcuts.Call(() =>
Iterator.Iterate(context, self, sequence, template, ifEmpty)
))
.Finally(context.Call(o => o.UnregisterValueProvider((IValueProvider)self)))
);
})));
}
private static void RenderSection(
object value,
BindingContext context,
Action <BindingContext, TextWriter, object> body,
Action <BindingContext, TextWriter, object> inversion,
BlockParamsValueProvider blockParamsValueProvider
)
{
switch (value)
{
case bool boolValue when boolValue:
body(context, context.TextWriter, context);
return;
case null:
case object _ when HandlebarsUtils.IsFalsyOrEmpty(value):
inversion(context, context.TextWriter, context);
return;
case string _:
body(context, context.TextWriter, value);
return;
case IEnumerable enumerable:
Iterator.Iterate(context, blockParamsValueProvider, enumerable, body, inversion);
break;
default:
body(context, context.TextWriter, value);
break;
}
}
private static void IterateEnumerable(BindingContext context,
BlockParamsValueProvider blockParamsValueProvider,
IEnumerable target,
Action <BindingContext, TextWriter, object> template,
Action <BindingContext, TextWriter, object> ifEmpty)
{
using (var iterator = IteratorValueProvider.Create())
{
blockParamsValueProvider?.Configure(BlockParamsEnumerableConfiguration, iterator);
iterator.Index = 0;
var enumerable = new ExtendedEnumerable <object>(target);
bool enumerated = false;
foreach (var enumerableValue in enumerable)
{
enumerated = true;
iterator.Value = enumerableValue.Value;
iterator.First = enumerableValue.IsFirst;
iterator.Last = enumerableValue.IsLast;
using (var innerContext = context.CreateChildContext(iterator.Value))
{
innerContext.RegisterValueProvider(iterator);
template(context, context.TextWriter, innerContext);
innerContext.UnregisterValueProvider(iterator);
}
}
if (iterator.Index == 0 && !enumerated)
{
ifEmpty(context, context.TextWriter, context.Value);
}
}
}
private static void IterateList(BindingContext context,
BlockParamsValueProvider blockParamsValueProvider,
IList target,
Action <BindingContext, TextWriter, object> template,
Action <BindingContext, TextWriter, object> ifEmpty)
{
using (var iterator = IteratorValueProvider.Create())
{
blockParamsValueProvider?.Configure(BlockParamsEnumerableConfiguration, iterator);
var count = target.Count;
for (iterator.Index = 0; iterator.Index < count; iterator.Index++)
{
iterator.Value = target[iterator.Index];
iterator.First = iterator.Index == 0;
iterator.Last = iterator.Index == count - 1;
using (var innerContext = context.CreateChildContext(iterator.Value))
{
innerContext.RegisterValueProvider(iterator);
template(context, context.TextWriter, innerContext);
innerContext.UnregisterValueProvider(iterator);
}
}
if (iterator.Index == 0)
{
ifEmpty(context, context.TextWriter, context.Value);
}
}
}
public static void Helper(BindingContext context, char prefix, object value,
Action <BindingContext, TextWriter, object> body, Action <BindingContext, TextWriter, object> inverse,
BlockParamsValueProvider blockParamsValueProvider)
{
if (prefix == '#')
{
RenderSection(value, context, body, inverse, blockParamsValueProvider);
}
else
{
RenderSection(value, context, inverse, body, blockParamsValueProvider);
}
}
private static void LateBoundCall(
string helperName,
char helperPrefix,
BindingContext bindingContext,
IReaderContext readerContext,
TextWriter output,
HelperOptions options,
Action <BindingContext, TextWriter, object> body,
Action <BindingContext, TextWriter, object> inverse,
dynamic context,
BlockParamsValueProvider blockParamsValueProvider,
params object[] arguments
)
{
try
{
if (bindingContext.Configuration.BlockHelpers.TryGetValue(helperName, out var helper))
{
helper(output, options, context, arguments);
return;
}
foreach (var resolver in bindingContext.Configuration.HelperResolvers)
{
if (!resolver.TryResolveBlockHelper(helperName, out helper))
{
continue;
}
helper(output, options, context, arguments);
return;
}
var segment = ChainSegment.Create(helperName);
bindingContext.TryGetContextVariable(ref segment, out var value);
DeferredSectionBlockHelper.Helper(bindingContext, helperPrefix, value, body, inverse, blockParamsValueProvider);
}
catch (Exception e)
{
throw new HandlebarsRuntimeException($"Error occured while executing `{helperName}.`", e, readerContext);
}
}
public static void Iterate(BindingContext context,
BlockParamsValueProvider blockParamsValueProvider,
object target,
Action <BindingContext, TextWriter, object> template,
Action <BindingContext, TextWriter, object> ifEmpty)
{
if (!HandlebarsUtils.IsTruthy(target))
{
ifEmpty(context, context.TextWriter, context.Value);
return;
}
var targetType = target.GetType();
if (!(context.Configuration.ObjectDescriptorProvider.CanHandleType(targetType) &&
context.Configuration.ObjectDescriptorProvider.TryGetDescriptor(targetType, out var descriptor)))
{
ifEmpty(context, context.TextWriter, context.Value);
return;
}
if (!descriptor.ShouldEnumerate)
{
var properties = descriptor.GetProperties(target);
if (properties is IList propertiesList)
{
IterateObjectWithStaticProperties(context, descriptor, blockParamsValueProvider, target, propertiesList, targetType, template, ifEmpty);
return;
}
IterateObject(context, descriptor, blockParamsValueProvider, target, properties, targetType, template, ifEmpty);
return;
}
if (target is IList list)
{
IterateList(context, blockParamsValueProvider, list, template, ifEmpty);
return;
}
IterateEnumerable(context, blockParamsValueProvider, (IEnumerable)target, template, ifEmpty);
}
private static void IterateObject(BindingContext context,
ObjectDescriptor descriptor,
BlockParamsValueProvider blockParamsValueProvider,
object target,
IEnumerable <object> properties,
Type targetType,
Action <BindingContext, TextWriter, object> template,
Action <BindingContext, TextWriter, object> ifEmpty)
{
using (var iterator = ObjectEnumeratorValueProvider.Create(context.Configuration))
{
blockParamsValueProvider?.Configure(BlockParamsObjectEnumeratorConfiguration, iterator);
iterator.Index = 0;
var accessor = descriptor.MemberAccessor;
var enumerable = new ExtendedEnumerable <object>(properties);
bool enumerated = false;
foreach (var enumerableValue in enumerable)
{
enumerated = true;
iterator.Key = enumerableValue.Value.ToString();
var key = iterator.Key.Intern();
iterator.Value = accessor.TryGetValue(target, targetType, key, out var value) ? value : null;
iterator.First = enumerableValue.IsFirst;
iterator.Last = enumerableValue.IsLast;
iterator.Index = enumerableValue.Index;
using (var innerContext = context.CreateChildContext(iterator.Value))
{
innerContext.RegisterValueProvider(iterator);
template(context, context.TextWriter, innerContext);
innerContext.UnregisterValueProvider(iterator);
}
}
if (iterator.Index == 0 && !enumerated)
{
ifEmpty(context, context.TextWriter, context.Value);
}
}
}
private static void IterateObjectWithStaticProperties(BindingContext context,
ObjectDescriptor descriptor,
BlockParamsValueProvider blockParamsValueProvider,
object target,
IList properties,
Type targetType,
Action <BindingContext, TextWriter, object> template,
Action <BindingContext, TextWriter, object> ifEmpty)
{
using (var iterator = ObjectEnumeratorValueProvider.Create(context.Configuration))
{
blockParamsValueProvider?.Configure(BlockParamsObjectEnumeratorConfiguration, iterator);
var accessor = descriptor.MemberAccessor;
var count = properties.Count;
for (iterator.Index = 0; iterator.Index < count; iterator.Index++)
{
iterator.Key = properties[iterator.Index].ToString();
iterator.Value = accessor.TryGetValue(target, targetType, iterator.Key, out var value) ? value : null;
iterator.First = iterator.Index == 0;
iterator.Last = iterator.Index == count - 1;
using (var innerContext = context.CreateChildContext(iterator.Value))
{
innerContext.RegisterValueProvider(iterator);
template(context, context.TextWriter, innerContext);
innerContext.UnregisterValueProvider(iterator);
}
}
if (iterator.Index == 0)
{
ifEmpty(context, context.TextWriter, context.Value);
}
}
}
protected override Expression VisitBlockHelperExpression(BlockHelperExpression bhex)
{
var isInlinePartial = bhex.HelperName == "#*inline";
var context = ExpressionShortcuts.Arg <BindingContext>(CompilationContext.BindingContext);
var bindingContext = isInlinePartial
? context.Cast <object>()
: context.Property(o => o.Value);
var readerContext = ExpressionShortcuts.Arg(bhex.Context);
var body = FunctionBuilder.CompileCore(((BlockExpression)bhex.Body).Expressions, CompilationContext.Configuration);
var inverse = FunctionBuilder.CompileCore(((BlockExpression)bhex.Inversion).Expressions, CompilationContext.Configuration);
var helperName = bhex.HelperName.TrimStart('#', '^');
var textWriter = context.Property(o => o.TextWriter);
var arguments = ExpressionShortcuts.Array <object>(bhex.Arguments.Select(o => FunctionBuilder.Reduce(o, CompilationContext)));
var configuration = ExpressionShortcuts.Arg(CompilationContext.Configuration);
var reducerNew = ExpressionShortcuts.New(() => new LambdaReducer(context, body, inverse));
var reducer = ExpressionShortcuts.Var <LambdaReducer>();
var blockParamsProvider = ExpressionShortcuts.Var <BlockParamsValueProvider>();
var blockParamsExpression = ExpressionShortcuts.Call(
() => BlockParamsValueProvider.Create(context, ExpressionShortcuts.Arg <BlockParam>(bhex.BlockParams))
);
var helperOptions = ExpressionShortcuts.New(
() => new HelperOptions(
reducer.Property(o => o.Direct),
reducer.Property(o => o.Inverse),
blockParamsProvider,
configuration)
);
var blockHelpers = CompilationContext.Configuration.BlockHelpers;
if (blockHelpers.TryGetValue(helperName, out var helper))
{
return(ExpressionShortcuts.Block()
.Parameter(reducer, reducerNew)
.Parameter(blockParamsProvider, blockParamsExpression)
.Line(blockParamsProvider.Using((self, builder) =>
{
builder
.Line(context.Call(o => o.RegisterValueProvider((IValueProvider)self)))
.Line(ExpressionShortcuts.Try()
.Body(ExpressionShortcuts.Call(
() => helper(textWriter, helperOptions, bindingContext, arguments)
))
.Finally(context.Call(o => o.UnregisterValueProvider((IValueProvider)self)))
);
})));
}
foreach (var resolver in CompilationContext.Configuration.HelperResolvers)
{
if (resolver.TryResolveBlockHelper(helperName, out helper))
{
return(ExpressionShortcuts.Block()
.Parameter(reducer, reducerNew)
.Parameter(blockParamsProvider, blockParamsExpression)
.Line(blockParamsProvider.Using((self, builder) =>
{
builder
.Line(context.Call(o => o.RegisterValueProvider((IValueProvider)self)))
.Line(ExpressionShortcuts.Try()
.Body(ExpressionShortcuts.Call(
() => helper(textWriter, helperOptions, bindingContext, arguments)
))
.Finally(context.Call(o => o.UnregisterValueProvider((IValueProvider)self)))
);
})));
}
}
var helperPrefix = bhex.HelperName[0];
return(ExpressionShortcuts.Block()
.Parameter(reducer, reducerNew)
.Parameter(blockParamsProvider, blockParamsExpression)
.Line(blockParamsProvider.Using((self, builder) =>
{
builder
.Line(context.Call(o => o.RegisterValueProvider((IValueProvider)self)))
.Line(ExpressionShortcuts.Try()
.Body(ExpressionShortcuts.Call(
() => LateBoundCall(
helperName,
helperPrefix,
context,
(IReaderContext)readerContext,
textWriter, helperOptions,
body,
inverse,
bindingContext,
self,
arguments
)
))
.Finally(context.Call(o => o.UnregisterValueProvider((IValueProvider)self)))
);
})));
}