InterMedia clipboard: cannot get object view

Question

Hi all.
I'm trying to use clipboard against 8.1.6r2 on Linux.
I've got a table with a primary key column and a BLOB column, and I created the necessary batch of procedures, modified to work with the BLOB column--I'm not using the ORDSYS types. This column will be storing PDFs and Word documents.
I can see the table view, but I can't double-click on the object icon and get an object view. Am I barking up the wrong tree, trying to load Word/PDFs via the clipboard? If not, where I can start looking to fix this problem?
Thanks for info.
-John

Answer 1

Hi,
The interMedia Clipboard is able to recognize multimedia data in object columns only. Furthermore, by default, it recognizes only interMedia objects, like ORDImage, ORDAudio, etc. However, it is possible to use the interMedia Clipboard to handle any object type, providing one 'teaches' it how to handle types it knows nothing about. If you have a table with a simple BLOB column, then you can create a new type to represent the multimedia data in the BLOB column, then create a view on the base table and map the BLOB column into the user-defined type. I've illustrated how to do this in the following example; however, please be aware that this is an undocumented and unsupported feature.
Hope this helps,
Simon
Here's an example of a simple table that holds documents in a BLOB column. If the table is used only to store documents of a single type, then you could skip the MIME type column. If you wanted, you could include a last-modified column and use it to return an appropriate HTTP status if a browser cache contains an up-to-date version.
SQL> create table mydocs ( docid varchar2(32), doc blob, mimetype varchar2(100) );The object type MYDOCSTYPE created below will be used by the Clipboard to recognize the presence of a multimedia data column it can handle.
create or replace type mydoctype as object ( doc blob, mimetype varchar2(100) );
/The MYDOCSVIEW is a view of the base table that uses MYDOCSTYPE to view the document.
create view mydocsview as
select d.docid, mydoctype( d.doc, d.mimetype ) mydoc
from mydocs d;The following 3 PL/SQL procedures are normally generated by the Clipboard Wizard; however, we have to do them by hand because the Clipboard recognizes only the interMedia types.
The MYDOC_INSERT procedure is used by the Clipboard to insert a new row into the MYDOCS table.
create or replace procedure mydocs_insert
( in_docid in varchar2, out_rowid out varchar2 ) as
begin
insert into mydocsview ( docid, mydoc ) values
( in_docid, mydoctype ( null, null ) )
returning rowid into out_rowid;
end;
/The MYDOCS_GET and MYDOCS_PUT are the mediaget and mediaput procedures used by the Web Agent to access the document data.
create or replace procedure mydocs_get
( ord_procedure_path in varchar2, ord_content_type out varchar2,
ord_content_length out number, ord_content_blob out blob ) as
begin
select d.mydoc.mimetype, dbms_lob.getlength( d.mydoc.doc ), d.mydoc.doc
into ord_content_type, ord_content_length, ord_content_blob
from mydocsview d where d.docid = ord_procedure_path;
end;
create or replace procedure mydocs_put
( ord_procedure_path in varchar2,
ord_content_type in varchar2,
ord_content_blob out blob ) as
begin
update mydocsview d set d.mydoc.doc = empty_blob(),
d.mydoc.mimetype = ord_content_type
where docid = ord_procedure_path;
select d.mydoc.doc into ord_content_blob from mydocsview d
where docid = ord_procedure_path for update;
end;
/All the above happens in the user's schema. Now we have to update the Clipboard's metadata in the ORDSYS schema. As before, the Clipboard normally does this, but we have to do it because we're not dealing with an interMedia type.
First tell the Clipboard about the new MYDOCTYPE object type: its in schema SCOTT, its names is MYDOCTYPE, it can hold ANY media data (contrast with IMAGE, AUDIO or VIDEO that are built-in media types the Clipboard knows how to handle), its stored as a BLOB and the BLOB is stored in the .DOC attribute (don't forget the .) of the MYDOCTYPE object type. Note that case is important here for all schema object names.
connect ordsys/ordsys
delete from mw$catalog_by_typ where type_name = 'MYDOCTYPE';
insert into mw$catalog_by_typ values (
'SCOTT', 'MYDOCTYPE', 'ANY', 'BLOB', '.DOC' );
insert into mw$catalog_by_tab values (
'SCOTT', 'MYDOCSVIEW', 'DOCID', 'MYDOCS_INSERT', NULL );
insert into mw$catalog_by_col values (
'SCOTT', 'MYDOCSVIEW', 'MY   DOC', 'MYDOCS_GET', 'MYDOCS_PUT', NULL );
commit;Once that's done, you should be able to run the Clipboard, insert new rows into the table, upload new documents, and so forth. Remember to select the view, not the base table when you open the schema in the Clipboard.
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