private static void Iterate(
ObjectEnumeratorBindingContext context,
IDynamicMetaObjectProvider target,
Action <TextWriter, object> template,
Action <TextWriter, object> ifEmpty)
{
if (HandlebarsUtils.IsTruthy(target))
{
context.Index = 0;
var meta = target.GetMetaObject(Expression.Constant(target));
foreach (var name in meta.GetDynamicMemberNames())
{
context.Key = name;
var value = GetProperty(target, name);
context.First = (context.Index == 0);
template(context.TextWriter, value);
context.Index++;
}
if (context.Index == 0)
{
ifEmpty(context.TextWriter, context.Value);
}
}
else
{
ifEmpty(context.TextWriter, context.Value);
}
}
public static void Iterate(
BindingContext context,
EncodedTextWriter writer,
ChainSegment[] blockParamsVariables,
object target,
TemplateDelegate template,
TemplateDelegate ifEmpty)
{
if (!HandlebarsUtils.IsTruthy(target))
{
using var frame = context.CreateFrame(context.Value);
ifEmpty(writer, frame);
return;
}
if (!ObjectDescriptor.TryCreate(target, out var descriptor))
{
throw new HandlebarsRuntimeException($"Cannot create ObjectDescriptor for type {descriptor.DescribedType}");
}
if (descriptor.Iterator == null)
{
throw new HandlebarsRuntimeException($"Type {descriptor.DescribedType} does not support iteration");
}
descriptor.Iterator.Iterate(writer, context, blockParamsVariables, target, template, ifEmpty);
}
private static void Iterate(
ObjectEnumeratorBindingContext context,
IEnumerable target,
Action <TextWriter, object> template,
Action <TextWriter, object> ifEmpty)
{
if (HandlebarsUtils.IsTruthy(target))
{
context.Index = 0;
var keysProperty = target.GetType().GetProperty("Keys");
if (keysProperty != null)
{
var keys = keysProperty.GetGetMethod().Invoke(target, null) as IEnumerable <object>;
if (keys != null)
{
foreach (var key in keys)
{
context.Key = key.ToString();
var value = target.GetType().GetMethod("get_Item").Invoke(target, new[] { key });
context.First = (context.Index == 0);
template(context.TextWriter, value);
context.Index++;
}
}
}
if (context.Index == 0)
{
ifEmpty(context.TextWriter, context.Value);
}
}
else
{
ifEmpty(context.TextWriter, context.Value);
}
}
private static void Iterate(
ObjectEnumeratorBindingContext context,
object target,
Action <TextWriter, object> template,
Action <TextWriter, object> ifEmpty)
{
if (HandlebarsUtils.IsTruthy(target))
{
context.Index = 0;
foreach (MemberInfo member in target.GetType()
.GetProperties(BindingFlags.Instance | BindingFlags.Public).OfType <MemberInfo>()
.Concat(
target.GetType().GetFields(BindingFlags.Public | BindingFlags.Instance)
))
{
context.Key = member.Name;
var value = AccessMember(target, member);
context.First = (context.Index == 0);
template(context.TextWriter, value);
context.Index++;
}
if (context.Index == 0)
{
ifEmpty(context.TextWriter, context.Value);
}
}
else
{
ifEmpty(context.TextWriter, context.Value);
}
}
private static void Iterate(
ObjectEnumeratorBindingContext context,
object target,
Action <TextWriter, object> template,
Action <TextWriter, object> ifEmpty)
{
if (HandlebarsUtils.IsTruthy(target))
{
context.Index = 0;
var targetType = target.GetType();
var properties = targetType.GetProperties(BindingFlags.Instance | BindingFlags.Public).OfType <MemberInfo>();
var fields = targetType.GetFields(BindingFlags.Public | BindingFlags.Instance);
foreach (var enumerableValue in new ExtendedEnumerable <MemberInfo>(properties.Concat(fields)))
{
var member = enumerableValue.Value;
context.Key = member.Name;
var value = AccessMember(target, member);
context.First = enumerableValue.IsFirst;
context.Last = enumerableValue.IsLast;
context.Index = enumerableValue.Index;
template(context.TextWriter, value);
}
if (context.Index == 0)
{
ifEmpty(context.TextWriter, context.Value);
}
}
else
{
ifEmpty(context.TextWriter, context.Value);
}
}
public static void Iterate(
BindingContext context,
EncodedTextWriter writer,
ChainSegment[] blockParamsVariables,
object target,
TemplateDelegate template,
TemplateDelegate ifEmpty)
{
if (!HandlebarsUtils.IsTruthy(target))
{
using var frame = context.CreateFrame(context.Value);
ifEmpty(writer, frame);
return;
}
var targetType = target.GetType();
if (!context.Configuration.ObjectDescriptorProvider.TryGetDescriptor(targetType, out var descriptor))
{
using var frame = context.CreateFrame(context.Value);
ifEmpty(writer, frame);
return;
}
if (!descriptor.ShouldEnumerate)
{
var properties = descriptor.GetProperties(descriptor, target);
if (properties is IList <ChainSegment> propertiesList)
{
IterateObjectWithStaticProperties(context, writer, blockParamsVariables, descriptor, target, propertiesList, targetType, template, ifEmpty);
return;
}
IterateObject(context, writer, descriptor, blockParamsVariables, target, properties, targetType, template, ifEmpty);
return;
}
if (target is IList list)
{
IterateList(context, writer, blockParamsVariables, list, template, ifEmpty);
return;
}
IterateEnumerable(context, writer, blockParamsVariables, (IEnumerable)target, template, ifEmpty);
}
private static void Iterate(
ObjectEnumeratorBindingContext context,
IEnumerable target,
Action <TextWriter, object> template,
Action <TextWriter, object> ifEmpty)
{
if (HandlebarsUtils.IsTruthy(target))
{
context.Index = 0;
var targetType = target.GetType();
#if netstandard
var keysProperty = targetType.GetRuntimeProperty("Keys");
#else
var keysProperty = targetType.GetProperty("Keys");
#endif
if (keysProperty != null)
{
var keys = keysProperty.GetGetMethod().Invoke(target, null) as IEnumerable;
if (keys != null)
{
var getItemMethodInfo = targetType.GetMethod("get_Item");
var parameters = new object[1];
foreach (var enumerableValue in new ExtendedEnumerable <object>(keys))
{
var key = parameters[0] = enumerableValue.Value;
context.Key = key.ToString();
var value = getItemMethodInfo.Invoke(target, parameters);
context.First = enumerableValue.IsFirst;
context.Last = enumerableValue.IsLast;
context.Index = enumerableValue.Index;
template(context.TextWriter, value);
}
}
}
if (context.Index == 0)
{
ifEmpty(context.TextWriter, context.Value);
}
}
else
{
ifEmpty(context.TextWriter, context.Value);
}
}
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);
}
public void BlockHelperWithInversion()
{
string source = "{{^test input}}empty{{else}}not empty{{/test}}";
var handlebars = Handlebars.Create();
handlebars.RegisterHelper("test", (output, options, context, arguments) =>
{
if (HandlebarsUtils.IsTruthy(arguments[0]))
{
options.Template(output, context);
}
else
{
options.Inverse(output, context);
}
});
var template = handlebars.Compile(source);
Assert.Equal("empty", template(null));
Assert.Equal("empty", template(new { otherInput = 1 }));
Assert.Equal("not empty", template(new { input = 1 }));
}