public bool CanRead(IEvaluationContext context, object target, string name)
{
if (target == null)
{
return(false);
}
var type = target is Type ? (Type)target : target.GetType();
if (type.IsArray && name.Equals("Length"))
{
return(true);
}
var cacheKey = new PropertyCacheKey(type, name, target is Type);
if (_readerCache.ContainsKey(cacheKey))
{
return(true);
}
var method = FindGetterForProperty(name, type, target);
if (method != null)
{
// Treat it like a property...
// The readerCache will only contain gettable properties (let's not worry about setters for now).
var typeDescriptor = method.ReturnType;
method = ClassUtils.GetInterfaceMethodIfPossible(method);
_readerCache[cacheKey] = new InvokerPair(method, typeDescriptor);
_typeDescriptorCache[cacheKey] = typeDescriptor;
return(true);
}
else
{
var field = FindField(name, type, target);
if (field != null)
{
var typeDescriptor = field.FieldType;
_readerCache[cacheKey] = new InvokerPair(field, typeDescriptor);
_typeDescriptorCache[cacheKey] = typeDescriptor;
return(true);
}
}
return(false);
}
public ITypedValue Read(IEvaluationContext context, object target, string name)
{
if (target == null)
{
throw new ArgumentNullException(nameof(target));
}
var type = target is Type ? (Type)target : target.GetType();
if (type.IsArray && name.Equals("Length"))
{
if (target is Type)
{
throw new AccessException("Cannot access length on array class itself");
}
var asArray = (Array)target;
return(new TypedValue(asArray.GetLength(0)));
}
var cacheKey = new PropertyCacheKey(type, name, target is Type);
_readerCache.TryGetValue(cacheKey, out var invoker);
_lastReadInvokerPair = invoker;
if (invoker == null || invoker.Member is MethodInfo)
{
var method = (MethodInfo)(invoker != null ? invoker.Member : null);
if (method == null)
{
method = FindGetterForProperty(name, type, target);
if (method != null)
{
// Treat it like a property...
// The readerCache will only contain gettable properties (let's not worry about setters for now).
var typeDescriptor = method.ReturnType;
method = ClassUtils.GetInterfaceMethodIfPossible(method);
invoker = new InvokerPair(method, typeDescriptor);
_lastReadInvokerPair = invoker;
_readerCache[cacheKey] = invoker;
}
}
if (method != null)
{
try
{
var value = method.Invoke(target, new object[0]);
return(new TypedValue(value, value != null ? value.GetType() : invoker.TypeDescriptor));
}
catch (Exception ex)
{
throw new AccessException("Unable to access property '" + name + "' through getter method", ex);
}
}
}
if (invoker == null || invoker.Member is FieldInfo)
{
var field = (FieldInfo)(invoker == null ? null : invoker.Member);
if (field == null)
{
field = FindField(name, type, target);
if (field != null)
{
invoker = new InvokerPair(field, field.FieldType);
_lastReadInvokerPair = invoker;
_readerCache[cacheKey] = invoker;
}
}
if (field != null)
{
try
{
var value = field.GetValue(target);
return(new TypedValue(value, value != null ? value.GetType() : invoker.TypeDescriptor));
}
catch (Exception ex)
{
throw new AccessException("Unable to access field '" + name + "'", ex);
}
}
}
throw new AccessException("Neither getter method nor field found for property '" + name + "'");
}
public OptimalPropertyAccessor(InvokerPair target)
{
_member = target.Member;
_typeDescriptor = target.TypeDescriptor;
}
public IPropertyAccessor CreateOptimalAccessor(IEvaluationContext context, object target, string name)
{
// Don't be clever for arrays or a null target...
if (target == null)
{
return(this);
}
var clazz = target is Type ? (Type)target : target.GetType();
if (clazz.IsArray)
{
return(this);
}
var cacheKey = new PropertyCacheKey(clazz, name, target is Type);
_readerCache.TryGetValue(cacheKey, out var invocationTarget);
if (invocationTarget == null || invocationTarget.Member is MethodInfo)
{
var method = (MethodInfo)invocationTarget?.Member;
if (method == null)
{
method = FindGetterForProperty(name, clazz, target);
if (method != null)
{
var typeDescriptor = method.ReturnType;
method = ClassUtils.GetInterfaceMethodIfPossible(method);
invocationTarget = new InvokerPair(method, typeDescriptor);
_readerCache[cacheKey] = invocationTarget;
}
}
if (method != null)
{
return(new OptimalPropertyAccessor(invocationTarget));
}
}
if (invocationTarget == null || invocationTarget.Member is FieldInfo)
{
var field = invocationTarget != null ? (FieldInfo)invocationTarget.Member : null;
if (field == null)
{
field = FindField(name, clazz, target is Type);
if (field != null)
{
invocationTarget = new InvokerPair(field, field.FieldType);
_readerCache[cacheKey] = invocationTarget;
}
}
if (field != null)
{
return(new OptimalPropertyAccessor(invocationTarget));
}
}
return(this);
}
