Display image in report page but just a link if file is not an image

Question

Hello,
I've been working on displaying an image in a report page but need to add some logic.
I would like to be able to call the image using a Region Source of type SQL instead of the HTML Expression. The reason for this is because I need to use logic to determine if the file is an image or not and to determine wether to show a thumbnail or just a link. I did find a "GET_BLOB_FILE_SRC" Function on the internet that suggests that I could do this but I need some help in making it work in my application.
Here it is as a Region Source of type SQL:
SELECT ID,
NAME,
CASE WHEN NVL(dbms_lob.getlength(document),0) = 0
THEN NULL
ELSE CASE WHEN attach_mimetype like 'image%'
THEN '<img
src="'||apex_util.get_blob_file_src('P4_DOCUMENT',id)||'" />'
ELSE '<a
href="'||apex_util.get_blob_file_src('P4_DOCUMENT',id)||'">Download</a>'
end
END new_img
FROM TEST_WITH_BLOB
If anyone can help me with this that would be appreciated.
Thanks
LEH

Answer 1

John,
The problem is that I do not know how to use the "GET_BLOB_FILE_SRC Function". I never got it to work but the HTML Expression did work for me. If you know how the GET_BLOB_FILE_SRC Function works then that would be helpful. I don't think it would be helpful if I posted my example on apex.oracle.com. But here is the information I have on the GET_BLOB_FILE_SRC Function.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
GET_BLOB_FILE_SRC Function
As an alternative to using the built-in methods of providing a download link, you can use the APEX_UTIL.GET_BLOB_FILE_SRC function. One advantage of this approach, is the ability to more specifically format the display of the image (with height and width tags). Please note that this approach is only valid if called from a valid Oracle Application Express session. Also, this method requires that the parameters that describe the BLOB to be listed as the format of a valid item within the application. That item is then referenced by the function.
See Also:
"About BLOB Support in Forms and Reports" in Oracle Application Express Application Builder User's Guide
Syntax
FUNCTION GET_BLOB_FILE_SRC (
    p_item_name           IN VARCHAR2 DEFAULT NULL,
    p_v1                  IN VARCHAR2 DEFAULT NULL,
    p_v2                  IN VARCHAR2 DEFAULT NULL,
    p_content_disposition IN VARCHAR2 DEFAULT NULL)
    RETURN VARCHAR2
Parameters
Table 1-28 describes the parameters available in GET_BLOB_FILE_SRC function.
Table 1-28 GET_BLOB_FILE_SRC Parameters
Parameter Description
p_item_name
Name of valid application page ITEM that with type FILE that contains the source type of DB column.
p_v1
Value of primary key column 1.
p_v2
Value of primary key column 2.
p_content_disposition
Specify inline or attachment, all other values ignored
Example
As a PLSQL Function Body:
RETURN '<img src="'||APEX_UTIL.GET_BLOB_FILE_SRC('P2_ATTACHMENT',:P2_EMPNO)||'" />';
As a Region Source of type SQL:
SELECT ID,
       NAME,
       CASE WHEN NVL(dbms_lob.getlength(document),0) = 0
            THEN NULL
            ELSE CASE WHEN attach_mimetype like 'image%'
                      THEN '<img
src="'||apex_util.get_blob_file_src('P4_DOCUMENT',id)||'" />'
                      ELSE '<a
href="'||apex_util.get_blob_file_src('P4_DOCUMENT',id)||'">Download</a>'
                      end
        END new_img
   FROM TEST_WITH_BLOB
The previous example illustrates how to display the BLOB within the report, if it can be displayed, and provide a download link, if it cannot be displayed.Thanks
LEH