Fetching HTML pages using Web Agent

Question

Hi,
I'm new to interMedia and Oracle Web Agent. Please excuse me if this topic has been covered before.
I have an iMedia database which I use to store and index HTML documents.
I installed and configured Web Agent in the hope that I could use it to fetch these HTML documents via a web browser using the same mechanism that is used for fetching multimedia data i.e. /<agent>/mediaget/get_html_doc/doc_name (where doc_name is a unique document identifier)
From what I can gather from the documention I need to create a new ORDSYS.ORD type which can return the mime type, content length etc for html documents but I'm guessing that somebody else has done this already.
My questions are:
1. Should the web agent be used to deliver HTML documents stored in a database or is there a more appropriate method of doing this?
2. If the Web Agent approach is correct, can somebody point me at some sample or example code.
Any help appreciated.
Dean
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Answer 1

Hi,
The interMedia Web Agent can be used to deliver HTML as well as multimedia data. Alternatively, you could use the PL/SQL gateway to deliver HTML data.
Database types aren't required to use the Web Agent to upload or retrieve deliver any multimedia data, including HTML, image, audio and video data. In fact, the Web Agent itself doesn't know anything about any database types, it just handles BLOBs, CLOBs (single byte characters) and BFILEs. Database types come into play only if you're using the interMedia Clipboard along with the Web Agent. The reason the Clipboard needs database types is that it uses them to recognize multimedia data in tables. By knowing the database, it can simply deduce the media type and so know how to handle the accompanying data. But if you're not using the Clipboard, you don't need a type. For example:
create table docs( id varchar2( 32 ), doc blob );
create or replace procedure get_doc( ord_procedure_path in varchar2,
ord_content_type out varchar2,
ord_content_blob out blob,
ord_content_length out number ) as
begin
select 'text/html', doc, dbms_lob.getlength( doc )
into ord_content_type, ord_content_blob, ord_content_length
from docs where id = ord_procedure_path;
end;
/If you do want to use the interMedia Clipboard to upload pages and/or browse pages stored in the database, then you will have to use a database type. However, you can use a view of the base table to achieve this. If this is the case, let me know and I'll point you at another discussion with instructions for how to do it.
The PL/SQL gateway (also called the PL/SQL agent) comes with Oracle iAS, the WebDB lightweight listener and OAS. If you have one of these application servers or web servers, please consult the accompanying documentation for how to use the HTP package to build and send a response to a client. If you have iAS, then you can use the WPG_DOCLOAD package to retrieve BLOBs, CLOBs and BFILEs directly, without having to use the HTP package. Try something like the following (I've not compiled/tested this, so don't know if it works or not, but its pretty close.)
create or replace procedure get_doc( doc_id in varchar2 )
as
local_blob blob;
begin
select doc into local_blob from docs where id = doc_id;
owa_util.mime_header( "text/html", TRUE );
wpg_docload.download_file( local_blob );
end;
/Hope this helps,
Simon
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