private static object ResolveValue(BindingContext context, object instance, ChainSegment chainSegment)
{
object resolvedValue;
if (chainSegment.IsVariable)
{
return(context.TryGetContextVariable(chainSegment, out resolvedValue)
? resolvedValue
: UndefinedBindingResult.Create(chainSegment));
}
if (chainSegment.IsThis)
{
return(instance);
}
if (context.TryGetVariable(chainSegment, out resolvedValue) ||
TryAccessMember(instance, chainSegment, context.Configuration, out resolvedValue))
{
return(resolvedValue);
}
if (chainSegment.IsValue && context.TryGetContextVariable(chainSegment, out resolvedValue))
{
return(resolvedValue);
}
return(UndefinedBindingResult.Create(chainSegment));
}
internal static bool TryAccessMember(object instance, ChainSegment chainSegment, ICompiledHandlebarsConfiguration configuration, out object value)
{
if (instance == null)
{
value = UndefinedBindingResult.Create(chainSegment);
return(false);
}
chainSegment = ResolveMemberName(instance, chainSegment, configuration);
return(new ObjectAccessor(instance).TryGetValue(chainSegment, out value));
}
internal UndefinedBindingResult GetUndefinedBindingResult(ICompiledHandlebarsConfiguration configuration)
{
if (_undefinedBindingResult != null)
{
return(_undefinedBindingResult);
}
lock (_lock)
{
return(_undefinedBindingResult ??
(_undefinedBindingResult = new UndefinedBindingResult(this, configuration)));
}
}
internal static bool TryAccessMember(object instance, ChainSegment chainSegment, ICompiledHandlebarsConfiguration configuration, out object value)
{
if (instance == null)
{
value = UndefinedBindingResult.Create(chainSegment);
return(false);
}
chainSegment = ResolveMemberName(instance, chainSegment, configuration);
value = null;
return(ObjectDescriptor.TryCreate(instance, configuration.ObjectDescriptorProvider, out var descriptor) &&
descriptor.MemberAccessor.TryGetValue(instance, chainSegment, out value));
}
private object ResolveValue(BindingContext context, object instance, string segment)
{
object resolvedValue = new UndefinedBindingResult(segment, CompilationContext.Configuration);
if (segment.StartsWith("@"))
{
var contextValue = context.GetContextVariable(segment.Substring(1));
if (contextValue != null)
{
resolvedValue = contextValue;
}
}
else if (segment == "this" || segment == string.Empty)
{
resolvedValue = instance;
}
else
{
resolvedValue = AccessMember(instance, segment);
}
return(resolvedValue);
}
public ObjectIteratorValues(BindingContext bindingContext) : this()
{
var configuration = bindingContext.Configuration;
_data = bindingContext.ContextDataObject;
_supportLastInObjectIterations = configuration.Compatibility.SupportLastInObjectIterations;
_wellKnownVariables = bindingContext.WellKnownVariables;
if (!_supportLastInObjectIterations)
{
var undefined = UndefinedBindingResult.Create(ChainSegment.Last);
_data.AddOrReplace(ChainSegment.Last, undefined, out _wellKnownVariables[(int)ChainSegment.Last.WellKnownVariable]);
}
else
{
_data.AddOrReplace(ChainSegment.Last, BoxedValues.False, out _wellKnownVariables[(int)ChainSegment.Last.WellKnownVariable]);
}
_data.AddOrReplace(ChainSegment.Key, null, out _wellKnownVariables[(int)ChainSegment.Key.WellKnownVariable]);
_data.AddOrReplace(ChainSegment.Value, null, out _wellKnownVariables[(int)ChainSegment.Value.WellKnownVariable]);
_data.AddOrReplace(ChainSegment.First, BoxedValues.True, out _wellKnownVariables[(int)ChainSegment.First.WellKnownVariable]);
_data.AddOrReplace(ChainSegment.Index, BoxedValues.Zero, out _wellKnownVariables[(int)ChainSegment.Index.WellKnownVariable]);
}
public static object ResolvePath(BindingContext context, PathInfo pathInfo)
{
if (!pathInfo.HasValue)
{
return(null);
}
if (pathInfo.IsPureThis)
{
return(context.Value);
}
var instance = context.Value;
var throwOnUnresolvedBindingExpression = context !.Configuration.ThrowOnUnresolvedBindingExpression;
var segments = pathInfo.Segments;
for (var segmentIndex = 0; segmentIndex < segments.Length; segmentIndex++)
{
var segment = segments[segmentIndex];
if (segment.IsThis)
{
continue;
}
if (segment.IsParent)
{
context = context !.ParentContext;
if (context == null)
{
instance = UndefinedBindingResult.Create("..");
goto undefined;
}
instance = context.Value;
throwOnUnresolvedBindingExpression = context.Configuration.ThrowOnUnresolvedBindingExpression;
continue;
}
var pathChain = segment.PathChain;
if (!TryResolveValue(pathInfo.IsVariable, context, pathChain[0], instance, out instance))
{
instance = UndefinedBindingResult.Create(pathChain[0]);
goto undefined;
}
for (var index = 1; index < pathChain.Length; index++)
{
if (TryAccessMember(context, instance, pathChain[index], out instance))
{
continue;
}
instance = UndefinedBindingResult.Create(pathChain[index]);
goto undefined;
}
}
return(instance);
undefined:
if (throwOnUnresolvedBindingExpression)
{
Throw.Undefined(pathInfo, (UndefinedBindingResult)instance);
}
return(instance);
}
public static void Undefined(PathInfo pathInfo, UndefinedBindingResult undefinedBindingResult) => throw new HandlebarsUndefinedBindingException(pathInfo, undefinedBindingResult);
/// <summary>
/// In case it's an UndefinedBindingResult, just try to convert the value using Json.
/// This logic adds functionality like parsing a list.
/// </summary>
/// <param name="undefinedBindingResult">The property value</param>
/// <param name="parsedValue">The parsed value</param>
/// <returns>true in case parsing is ok, else false</returns>
private static bool TryParseUndefinedBindingResult(UndefinedBindingResult undefinedBindingResult, out List <object?>?parsedValue)
{
return(ArrayUtils.TryParseAsObjectList(undefinedBindingResult.Value, out parsedValue));
}
