I too have encountered a very similar issue, though with the corresponding "Set" version of DelegatePropertyGetAccessor. From what I could tell, there appears to be a limitation in current ibatis where domain objects are restricted from being generics or having them as properties, except for a few that are specifically or transparently supported by ibatis (e.g. IList<T>, Nullable<T>).
Unfortunately, I've not had the time to dig into the ibatis code involved, so I have had to dumb down my domain model quite a bit in places where generics could have been used to great advantage. That "dumbing down" is now impacting complexity more and more as I work my way up through the layers of my application. :( I'll present a small example here in case it is of help to the ibatis devs: Given a domain model layer supertype called Entity, if I attempt to map via ibatis the data for another class called Similarity<T> where T : Entity, I will get the kind of exception Finn has described, though for me it was on the "Set" side when using Similarity<T> in a result map. This error also persisted even if I took the generic out of the class's explicit definition and instead referenced a class called EntitySimilarity : Similarity<Entity>. Jeremy -----Original Message----- From: Finn Nielsen [mailto:[EMAIL PROTECTED] Sent: Friday, October 20, 2006 5:19 AM To: [email protected] Subject: MethodAccessException in emitted code "GetImplementation" Hi, First of all, great work with iBATIS. :) Now, on to the subject. I am not sure if my observation is a problem with iBATIS, a feature request or a problem with my own code. Therefore I will start out by sending this mail. An example of my environment (heavily abstracted): .NET version 2.0. iBATIS binaries: IBatisNet.Common 1.4.1 IBatisNet.DataMapper 1.5.1 IBatisNet.DataAccess 1.8.1 I have a Common assembly which defines common utility types for use within the domain model. The utility types often use generics. The Common assembly is dependant on two other assemblies not mentioned here, but naturally only using public stuff in the dependant assemblies. One particular class is: public class SpecialReference<T> where T : class { // stuff omitted public T Value { get { /*...*/ } set { /*...*/ } } } I have a Model assembly which contains the domain model types. Is dependant on the Common assembly. Two fictive domain model classes are: public class DomainObjectA { private int identifier; // stuff omitted } public class DomainObjectB { private SpecialReference<DomainObjectA> domainObjectA; // stuff omitted } In my mapping xml file for DomainObjectB I got stuff like: <insert id="insertDomainObjectB" parameterClass="DomainObjectB"> INSERT INTO DOM_OBJ_B (columns) VALUES (/* omitted stuff */, #domainObjectA.Value.identifier#, /* omitted stuff */) </insert> The symptom: When I insert a DomainObjectB I get a MethodAccessException where the stack trace points to "GetImplementation". I know that domainObjectA within the DomainObjectB instance has been properly initialized. Analysis I tried referencing the iBATIS source (Source Revision 426164) with which I was able to reporduce the problem. The MethodAccessException occured in the emitted code within IBatisNet.Common.Utilities.Objects.Members.DelegatePropertyGetAccessor. That is, when the emitted code was invoked using the GetValue delegate. The odd thing is, that I am sure that the #specialDomainObjectA.Value.identifier# is valid, in the sence that the SpecialReference<T> class is public, and so is the Value property. Next I tried in the IBatis.Common.2005 project to reference the Model and Common assemblies, and implement my own hardcoded GetValue delegate which was typed for DomainObjectB, but basically did the same as the emitted code. That is, cast the input object to the specific type, invoke the get property and return the result. This worked, i.e. I got no MethodAccessException. Afterwards I removed my own experimentation code from the iBATIS source and also removed the references for the assemblies Model and Common. After a couple of other unsuccessfull attempts i found a "cure". Within IBatisNet.Common.Utilities.Objects.Members.DelegatePropertyGetAccessor a line of code states: DynamicMethod dynamicMethod = new DynamicMethod("GetImplementation", typeof(object), new Type[] { typeof(object) }, this.GetType().Module, false); I flipped the last boolean to true, which means to skip JIT visibility checks on members of all the types in all modules. This worked. Question Is the need for changing the boolean from false to true: 1. A flaw in the IBatisNet.Common assembly (IBatisNet.Common.Utilities.Objects.Members.DelegatePropertyGetAccessor and IBatisNet.Common.Utilities.Objects.Members.DelegatePropertySetAccessor classes). 2. A flaw in my code, or 3. A feature request for IBatisNet.Common Thanks for taking the time to read my mail. :) Kind regards Finn Nielsen
