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This Technical Note describes how to create an AOCE catalog services
specification structure (DSSpec) for an AOCE business card catalog item, given
just a file system specification record (FSSpec) for the item.
[Sep 01 1994]
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Introduction
The AOCE catalog services specification structure, defined by the
DSSpec data type (see Inside Macintosh :AOCE Application
Interfaces 2-36), is used throughout AOCE for performing various tasks
such as getting and setting attributes in a record, specifying message
addresses, etc. Many of the AOCE software routines defined in Inside
Macintosh :AOCE Application Interfaces will give you a
DSSpec for a given catalog item. For example, the Standard Catalog
package contains a Catalog-Browsing panel, which allows the user to select
records in catalogs. Once a selection is made, the selected item is returned as
a DSSpec structure.
However, there are instances where you will be given just an FSSpec
for a catalog item, and you will need to construct a DSSpec structure
for that same item. For example, if your application uses the Drag Manager to
handle dragging HFS objects onto your application's windows, it's possible that
you will receive a drag of an HFS object that represents an AOCE catalog item
(like a business card). In this case, all you are given for the object is an
FSSpec structure. If you wanted to use some of the routines defined in
the AOCE Catalog Manager on that item, you would need to pass a
RecordID or DSSpec structure describing that item.
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Building a DSSpec
The following describes how to construct a DSSpec (from just a
FSSpec) for a business card. Basically, business cards are degenerate
personal catalogs containing a distinguished record. To find the distinguished
record, we look for a pseudonym with a known type. By enumerating that
pseudonym you can find the distinguished record. The process is as follows:
- Open the business card with
DirOpenPersonalDirectory to get the reference number.
- Use
DirEnumerateGet to get the distinguished record's CID (the CID and reference number are enough to access the record).
To make a fully specified packedDSSpec:
- Call
DirGetNameAndType passing the CID gotten above, to get the distinguished record's type (use the file name as the record's name. If it is not the same, it is OK to set the record's name to the file name).
- Call
DirMakePersonalDirectoryRLI, using the business card reference number to get the RLI.
- Create the
packedDSSpec using the OCEPackedDSSpecSize and OCEPackedDSSpec routines.
Code Example
Here is the code, written in MPW C. You call the ConstructPackedDSSpec
routine, passing a valid FSSpec along with a pointer to an empty
PackedDSSpecPtr type variable. The code then returns a pointer to a
valid PackedDSSpec structure in the packedDSSpecPtr
parameter:
/* global data */
#define kEnumBufferSize (4096) /* Working data buffer */
/*****************************************************************
* ConstructPackedDSSpec
*
* main code that builds a packedDSSpec struct from an FSSpec
* for a Business Card.
*****************************************************************/
OSErr ConstructPackedDSSpec( FSSpecPtr fsspecPtr,
PackedDSSpecPtr *packedDSSpecPtr )
{
OSErr err;
unsigned short packedSpecSize;
DSSpec dsspec;
RecordID rid;
RString name,type;
PackedRLI packedRLI;
LocalRecordID localRID;
CreationID cid;
name.dataLength = kRStringMaxBytes;
type.dataLength = kRStringMaxBytes;
OCENewLocalRecordID(&name,&type,&cid,&localRID);
OCENewRecordID(&packedRLI,&localRID,&rid);
err = GetRecordID(fsspecPtr,
&rid,
OCEGetIndRecordType(kBusinessCardRecTypeNum));
if (err == noErr)
{
dsspec.extensionType = kOCEentnDSSpec;
dsspec.extensionSize = 0;
dsspec.extensionValue = NULL;
dsspec.entitySpecifier = &rid;
packedSpecSize = OCEPackedDSSpecSize(&dsspec);
*packedDSSpecPtr = (PackedDSSpecPtr)NewPtr(packedSpecSize);
err = MemError();
if (err == noErr)
{
err = OCEPackDSSpec(&dsspec, *packedDSSpecPtr, packedSpecSize);
}
}
return (err);
}
/*****************************************************************
* GetRecordID
*
*
*****************************************************************/
OSErr GetRecordID( FSSpecPtr fsspec,
RecordIDPtr ridPtr,
RStringPtr recordType)
{
OSErr err;
DirParamBlock pb;
pb.openPersonalDirectoryPB.fsSpec = fsspec;
pb.openPersonalDirectoryPB.accessRequested = fsRdPerm;
/* get reference number for Business Card */
err = DirOpenPersonalDirectory(&pb);
if (err == noErr)
{
err = DoEnumerateGet( pb.openPersonalDirectoryPB.dsRefNum,
(long)&ridPtr->local,
recordType);
if (err == noErr)
{
pb.getNameAndTypePB.identity = 0;
pb.getNameAndTypePB.aRecord = ridPtr;
err = DirGetNameAndType (&pb, false);
if (err == noErr)
{
pb.makePersonalDirectoryRLIPB.fromFSSpec = fsspec;
pb.makePersonalDirectoryRLIPB.pRLIBufferSize = kRLIMaxBytes;
pb.makePersonalDirectoryRLIPB.pRLI = ridPtr->rli;
err = DirMakePersonalDirectoryRLI(&pb);
}
}
DirClosePersonalDirectory(&pb);
}
return (err);
}
/*****************************************************************
* DoEnumerateGet
*
*
*****************************************************************/
OSErr DoEnumerateGet(short dsRefNum,
long clientData,
RStringPtr recordType)
{
OSErr err;
RStringPtr typeList[1];
DirParamBlock dirParamBlock;
Ptr buffer;
#define GET (dirParamBlock.enumerateGetPB)
#define PARSE (dirParamBlock.enumerateParsePB)
buffer = NewPtr(kEnumBufferSize);
if (buffer == NULL)
err = MemError();
else
{
GET.dsRefNum = dsRefNum;
GET.identity = 0;
GET.aRLI = NULL; /* ignored if non-zero dsRefNum is passed */
GET.startingPoint = 0;
GET.sortBy = kSortByType;
GET.sortDirection = kSortForwards;
typeList[0] = recordType;
GET.typesList = &typeList;
GET.typeCount = 1;
GET.enumFlags = kEnumPseudonymMask;
GET.includeStartingPoint = true;
GET.matchNameHow = kMatchAll;
GET.matchTypeHow = kExactMatch;
GET.getBuffer = buffer;
GET.getBufferSize = kEnumBufferSize;
err = DirEnumerateGet (&dirParamBlock, false);
if (err == noErr || err == kOCEMoreData)
{
PARSE.clientData = clientData;
PARSE.eachEnumSpec = myForEachDirEnumSpec;
err = DirEnumerateParse (&dirParamBlock, false);
}
}
return (err);
#undef GET
#undef PARSE
}
/*****************************************************************
* myForEachDirEnumSpec
*
*
*****************************************************************/
static pascal Boolean myForEachDirEnumSpec (long clientData,
const DirEnumSpec *enumSpec)
{
OSErr err;
if ((enumSpec->enumFlag & kEnumPseudonymMask))
{
err = OCECopyLocalRecordID(&enumSpec->u.recordIdentifier,
(LocalRecordIDPtr)clientData);
return (true); /* stop, we found it */
}
else
return (false); /* get next one */
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References:
Inside Macintosh :AOCE Application Interfaces
Inside Macintosh :Files
Drag Manager Programmer's Guide
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