Re: Finding the primary key value in an abstract EOGenericObject class

Hi, Alan & Matt,

The methods that Alan is suggesting are both methods on  
ERXGenericRecord which is one of the Project Wonder extensions to  
EOF. These methods do not exist in WebObjects/EOF proper. However,  
even without using Project Wonder you can still get the primary key.

Presume these are defined:
     myEOGenericObject
     myEditingContext

Also, presume that your primary key is a simple key of (arbitrary)  
type PrimaryKeyValueClass.

If you want thePrimaryKeyValue, for myEOGenericObject which you've  
inserted into myEditingContext you would write:

   NSArray theKeys = myEditingContext.globalIDForObject 
(myEOGenericObject).keyValuesArray();

Then, if myEOGenericObject contains a simple primary key rather than  
a composite primary key, you could extract it with:

    PrimaryKeyValueClass thePrimaryKeyValue = (PrimaryKeyValueClass) 
theKeys.objectAtIndex(0);

or

     PrimaryKeyValueClass thePrimaryKeyValue = (PrimaryKeyValueClass) 
theKeys.lastObject();

With only one object in the array, the key is both the first and last  
object.  :-)


Alternatively, to obtain the primary key attributes as an  
NSDictionary rather than as an NSArray, you could write:

   NSDictionary theKeys = myEditingContext.globalIDForObject 
(myEOGenericObject).primaryKeyForGlobalID();

Then you could extract the key attribute or attributes from theKeys  
dictionary by name:

     PrimaryKeyValueClass thePrimaryKeyValue = (PrimaryKeyValueClass) 
theKeys.valueForKey(myKeysName);

Regards,
Jerry


On Jan 28, 2006, at 4:51 PM, Alan Ward wrote:
> primaryKey() returns it as a String, rawPrimaryKey() returns it as  
> whatever type it is.
>
> On Jan 28, 2006, at 1:22 PM, Matt Kime wrote:
>> Hello,
>>
>> Does anyone know how I can find the primary key value of any given
>> EOGenericObject class?I'm attempting to create an abstract class that
>> use to implement EOEnterpriseObjects with history features.
>>
>> many thanks,
>> matt


--
__ Jerry W. Walker,
    WebObjects Developer/Instructor for High Performance Industrial  
Strength Internet Enabled Systems

     [email protected]
     203 278-4085        office