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Chapter 1 - Resource Manager / Resource Manager Reference

Resource Manager Routines / Reading Resources Into Memory

GetNamedResource

You can use the GetNamedResource function to get a named resource.

FUNCTION GetNamedResource (theType: ResType; name: Str255)
                           : Handle;

theType

A resource type.

name

A name that uniquely identifies a resource of the specified type. Strings passed in this parameter are case-sensitive.

DESCRIPTION

The GetNamedResource function searches the resource maps in memory for the resource specified by the parameters theType and name. The resource maps in memory, which represent all the open resource forks, are arranged as a linked list. When GetNamedResource searches this list, it starts with the current resource file and progresses through the list in order (that is, in reverse chronological order in which the resource forks were opened) until it finds the resource's entry in one of the resource maps.

If GetNamedResource finds the specified resource entry in one of the resource maps and the entry contains a valid handle, the function returns that handle. If the entry contains a handle whose value is NIL, and if you haven't called SetResLoad with the load parameter set to FALSE, GetNamedResource attempts to read the resource into memory.

If the GetNamedResource function can't find the resource data, it returns NIL, and ResError returns the result code resNotFound. The GetNamedResource function also returns NIL if the resource data to be read into memory won't fit, in which case ResError returns an appropriate Memory Manager result code. If you call GetNamedResource with a resource type that can't be found in any of the resource maps of the open resource forks, the function returns NIL as well, but ResError returns the result code noErr. You should always check that the value of the returned handle is not NIL.

You can change the resource map search order by calling the UseResFile procedure before GetNamedResource.

SPECIAL CONSIDERATIONS

The GetNamedResource function may move or purge memory blocks in the application heap. Your application should not call this function at interrupt time.

RESULT CODES

noErr	0	No error
resNotFound	-192	Resource not found

SEE ALSO

To check for errors, call the ResError function as described on page 1-47.

To include ROM-resident system resources in the Resource Manager's search of the resource maps for open resource forks, use the RGetResource function as described on page 1-73.

For information about the UseResFile and SetResLoad procedures, see page 1-65 and page 1-74, respectively.