PA_GetBlobParameter

version 2003

PA_GetBlobParameter (params; index; blob) long

Parameter	Type		Description
params	PA_PluginParameters		Parameters received in PluginMain
index	short		Index of the parameter in params
blob	void *		Value (buffer) of the index parameter (a BLOB)
Function result	long		BLOB size

The routine PA_GetBlobParameter fills blob with the value (of type BLOB) of the index parameter in params and returns its size.

First call the routine with blob as 0L to retrieve the size of the buffer you should allocate. Then, allocate the buffer and call the routine again with the allocated buffer.

After using blob, you can dispose of it as it does not belong to 4th Dimension, it is a copy of the parameter. As usual, it is a good habit to dispose of memory that is no longer needed.

If you do not want to receive a copy of the BLOB (for memory optimization), you can use the PA_GetBlobHandleParameter routine, which returns a handle to the BLOB. In this case, remember that the handle belongs to 4th Dimension and you must not dispose of it.

See Create a new plug-in for a description of parameter accessors.

NOTE:

The first parameter starts at index 1.

The 3rd routine of the plug-in is named "pi_DoWithBlob".

The 4D developer is told to use it this way:

   pi_DoWithBlob($blob);// or BLOB, or <>BLOB, or [Table1]BlobField

   void PluginMain( long selector, PA_PluginParameters params )
   {
      switch ( selector )
      {
         . . .kInitPlugin, kDeinitPlugin

         case kMyRoutine : // declared as DoWithBob(&O) in the STR# resource
            DoWithABlob(params);
            break;

      }
   }

   void DoWithABlob (PA_PluginParameters params )
   {
         char   *blob;
         long   blobSize;

         blob = 0L;
         blobSize = PA_GetBlobParameter(params, 1, 0L);

         blob = malloc(textSize);
         blobSize = PA_GetBlobParameter(params, 1, blob);

      // Let's work with the blob
         DoSomethingWithThisBlob(blob);
      // We can now release the received copy 
         free(blob);
      }

Create a new plugin, PA_Blob, PA_GetBlobHandleParameter.

PA_GetLastError() keeps the last error that occurred before calling the routine.