Oracle Forms Web

Upload, edit and download files from/to the database with the

Webutil library

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1. Purpose

The purpose of this article is to demonstrate how, with the Webutil library, we can upload local documents into the database, edit those stored documents on the client machine, save modified documents to the database, and use the MSWord CheckSpell function.

The goal is to have, with Webutil, the same functionality as an “OLE CONTAINER” C/S component.

2. Upload local document to the database

Select a file on the client machine with the WEBUTIL_FILE.FILE_OPEN_DIALOG function

FUNCTION WEBUTIL_FILE.FILE_OPEN_DIALOG

(

directory_name,

file_name,

file_filter,

title

) return VARCHAR2;

directory_name is the name of the starting directory (let empty to start at the root)

file_name is the name of the searching file

file_filter is the list of file types to display (e.g. '|All files|*.*|' or '|Word Files|*.doc|Excel Files|*.xls|')

title is the title of the dialog box

Upload the selected document into the database with the Webutil_File_Transfer.Client_To_DB function

FUNCTION Webutil_File_Transfer.Client_To_DB

(

clientFile in VARCHAR2,

tableName in VARCHAR2,

columnName in VARCHAR2,

whereClause in VARCHAR2,

asynchronous in BOOLEAN default FALSE,

callbackTrigger in VARCHAR2 default NULL

) return BOOLEAN;

clientFile is the full file name returned by the File_Open_Dialog() function

tableName is the table that contains a BLOB column

columnName is the BLOB column you want to store the file

whereClause is the Where clause to identify a unique raw in the table

asynchronous allows form to re-draw its screen before the end of the upload

callbackTrigger is the name of a form-level trigger which will be called once the upload is completed.

Assume you want to store the c:\docs\doc.xls in the DOC column of the DOCUMENTS table where DOC_ID = 10, use the following instruction:

Declare

LB$Result BOOLEAN ;

Begin

LB$Result := Webutil_File_Transfer.Client_To_DB

(

‘c:\docs\doc.xls’,

‘DOCUMENTS’,

‘DOC’,

‘DOC_ID = 10’

) ;

End ;

Attention:

The Client_To_DB() function use an UPDATE statement to store the document in an existing BLOB column, so the corresponding raw must exists in the table before calling the function.

3. Download from database, edit on client machine and re-save document to database

Download the document on the client machine with the Webutil_File_Transfer.DB_To_Client function

FUNCTION DB_To_Client

(

clientFile in VARCHAR2,

tableName in VARCHAR2,

columnName in VARCHAR2,

whereClause in VARCHAR2

) return BOOLEAN;

clientFile is the local file name

tableName is the table that contains a BLOB column

columnName is the BLOB column you want to store the file

whereClause is the Where clause to identify a unique raw in the table

Edit the document with the Webutil_Host.blocking function

FUNCTION Blocking(cmd in VARCHAR2) return PROCESS_ID;

Example:

Declare

LC$Cmd Varchar2(256) ;

Ret WEBUTIL_HOST.PROCESS_ID ;

LN$Result Pls_Integer ;

LC$FicName Varchar2(128) := Name_In( ‘BLOB_TABLE.DOC_NAME’ ) ;

Begin

LC$Cmd := 'cmd /c start "" /WAIT "' || LC$FicName || '"' ;

Ret := WEBUTIL_HOST.blocking( LC$Cmd ) ;

LN$Result := WEBUTIL_HOST.Get_return_Code( Ret ) ;

End ;

Note the /WAIT parameter that wait the return of calling function before returning to Forms

Re-save the modified document into the database with the Webutil_File_Transfer.Client_To_DB function

Delete the temporary local file with the Webutil_File.Delete_File function

4. Call the CheckSpell MSWord function with CLIENT_OLE2

The following code allows to call the MSWord CheckSpell function and pass as an argument the content of a TEXT item

PROCEDURE CheckSpell

(

PC$Item in Varchar2

) IS

-------------------------------------------

-- Call the MSWord CheckSpell function --

-------------------------------------------

MyApplication client_ole2.OBJ_TYPE;

MyDocuments client_ole2.OBJ_TYPE;

MyDocument client_ole2.OBJ_TYPE;

MySelection client_ole2.OBJ_TYPE;

args client_ole2.LIST_TYPE;

Begin

MyApplication:=client_ole2.CREATE_OBJ('Word.Application');

client_ole2.SET_PROPERTY(MyApplication, 'Visible', 0);

MyDocuments:=client_ole2.GET_OBJ_PROPERTY(MyApplication, 'Documents');

MyDocument := CLIENT_OLE2.INVOKE_OBJ(MyDocuments,'add');

Myselection := CLIENT_OLE2.GET_OBJ_PROPERTY(Myapplication,'Selection');

client_ole2.SET_PROPERTY(Myselection,'Text',Name_in(PC$item));

client_ole2.INVOKE(MyDocument,'CheckSpelling');

MySelection:=client_ole2.GET_OBJ_PROPERTY(MyApplication, 'Selection');

client_ole2.INVOKE(mYSelection,'WholeStory');

client_ole2.INVOKE(MYSelection,'Copy');

COPY( CLIENT_OLE2.GET_CHAR_PROPERTY(Myapplication,'Selection'), PC$Item ) ;

args := CLIENT_OLE2.CREATE_ARGLIST;

client_ole2.ADD_ARG(args,0);

client_ole2.INVOKE(MyDocument,'Close',args);

client_ole2.DESTROY_ARGLIST(args);

client_ole2.INVOKE(MyApplication,'Quit');

client_ole2.RELEASE_OBJ(MySelection);

client_ole2.RELEASE_OBJ(MyDocument);

client_ole2.RELEASE_OBJ(MyDocuments);

client_ole2.RELEASE_OBJ(MyApplication);

copy(Substr(Replace(Name_in(PC$Item),CHR(13),CHR(10)),1,Length(Name_in(PC$Item))-1), PC$item );

Exception

When others then

Null ;

End;

You can call this procedure with the following code:

CheckSpell( :system.cursor_item ) ;

5. Sample dialog

The WEBUTIL_DOCS.fmb Forms module allow to test all these manipulations.

(Download the WEBUTIL_DOCS dialog)

Click the Select a local file… button to choose a file on your local machine

Click the Store local doc to database button to store the selected file in the database

The name of the new stored file is now displayed in the list of stored files

Double-click on the file name or click the Edit and save button to edit the document.

Run the CheckSpell function...

Click the Start the Word checkspelling button ...

This dialog is based on the BIN_DOCS table. You can use the following creation script.

CREATE TABLE BIN_DOCS

(

DOC_ID NUMBER(5) PRIMARY KEY,

NAME VARCHAR2(128 BYTE),

DOC BLOB

)

/

This basic sample could be the starting point of a most elaborated documentation application.

You could add some columns to the BIN_DOCS table to implement a check-in/check-out functionality that

allows every user to see a doc but only one could modify at the same time.