Error : Unable to bind foreign handler

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Simon Knight
Posts: 627
Joined: Wed Nov 04, 2009 11:41 am
Location: Gunthorpe, North Lincs, UK

Error : Unable to bind foreign handler

Post by Simon Knight » Thu Feb 06, 2020 3:59 pm

Hi,

Would someone be kind enough to have a look at the following foreign handler definition to see where my error is ?

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// Check authorisation to access Events - FAILS ???
// In Objective-C the type returned from authorizationStatusForEntityType is defined as NSInteger 
// which is an int on 32bit processor or long on 64bit processor.

private foreign handler ObjC_EKEventStoreAuthStatus(in pObj as ObjcID,in pEKEntityMaskEvent as CUint) \
			returns CULong \
			binds to "objc:EventKit>EKEventstore.-authorizationStatusForEntityType:"
The is being called by this line :

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put ObjC_EKEventStoreAuthStatus(sEventStore, 0) into tAuthorisationCode
sEventstore is declared with

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private variable sEventStore as optional ObjcObject
and tAuthorisationCode with

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variable tAuthorisationCode as optional Integer
sEventstore has been set to an EKEventstore object using calls to "alloc" and "init". If is tested as not nothing before the call to ObjC_EKEventStoreAuthStatus is made. The first time I initialised sEventstore I was prompted to provide permission so I believe that the creation of the object was successful.

I have been plugging away at this one call for most of the day and do not what else to try. Any thoughts?
best wishes
Skids

Simon Knight
Posts: 627
Joined: Wed Nov 04, 2009 11:41 am
Location: Gunthorpe, North Lincs, UK

Re: Error : Unable to bind foreign handler

Post by Simon Knight » Sun Feb 09, 2020 4:02 pm

Answering my own question. The definition that works is like this:

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private foreign handler ObjC_EKEventStoreAuthStatus(in pEKEntityMaskEvent as CUint) \
			returns CULong \
			binds to "objc:EventKit>EKEventStore.+authorizationStatusForEntityType:"
The key is that the method is a class method and not an instance method. So the reference to the instance has to be removed from from the parameters and the prefix to the method changed from a "-" to a "+".

Moral of the storey : Read the documentation, then read it a again.
best wishes
Skids

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