How to change connection for reports?

rbuser

I made a bunch of reports using ADOExpress for testing and I cannot open
them using another type of connection components. It seems to expect the
ADOExpress DADE classes to be present and usable.
How can I change the connection a report is bound to, to something else?
I saved the reports as rtms and I see they are text files ala dfm, but I am
sure there's a better way than replacing text inside those (which is quite a
bit) :-) Can anybody help me? Thanks!

--
Best regards,
Alessandro Federici

RemObjects Software, Inc.
http://www.remobjects.com

nardmoseley

To clarify the question for anyone else reading this:

1. Data Connection

A data connection for ADO is defined by a TADOConnection component. Create a
TADOConnection and assign it to the Designer.DataSettings. Now each new
DataView that you create will be assigned that connection name. This enables
the connection parameters to be modified at a later time.

2. DADE Plug-ins = Data Access Components

Each DADE plug-in implements a set of classes that support a specific type
of data access components: ADO, BDE, IBExpress, etc. The current DataView
architecture does not provide a simple way to convert from one type of data
access components to another. The issue is somewhat similar to the case in
which you place a TTable on a Delphi form and later want to change it to a
TADOTable. The TTable is saved in the .dfm file.

3. The following article contains guidelines for converting templates to use
a different type of DADE plug-in.


-------------------------------------------------
Tech Tip: Convert BDE Template Dataviews To ADO
-------------------------------------------------

Currently when DADE is used to create dataviews, the DatabaseName is stored
as part of the query definition. (This is consistent with Delphi's approach
to specifying a database connection for a Query object).

When you created the reports originally, the daDBBDE.pas BDE DADE plugin was
used. Now you want to use ADO. You've already changed the
Designer.Datasettings but this had no effect on the old reports. They still
try to use the BDE connection. Changing the Designer.DAtaSettings only works
for new dataviews that are created, because the new query dataviews are
using the daADO.pas ADO DADE plugin.

In order to convert the templates from BDE to ADO, at the minimum you have
to change the database name and the DADE plugin class names that are stored
in the templates. When a BDE dataview is created, its class type is a
TdaBDEQueryDataview. When an ADO dataview is created, its class type is
TdaADOQueryDataview. These class types are stored in the template. These
have to be changed before the template is loaded into a report.

First, compare a BDE report template to an ADO report template which both
connect to the same database table. Save a BDE and an ADO based report
template to separate ASCII text files. Now compare the dataview definitions.
Change the TdaBDEQueryDataview class name to TdaADOQueryDataview in the BDE
template. Change the BDE alias to your ADOConnection object. Then compare
the table name and field names of the BDE template to the ADO template and
change them accordingly, removing the .db extension on the table name is
necessary. Now load the converted BDE template in your ADO end user
application.

The first step is to make a backup of all your templates before continuing
with a programatic approach. You can convert the templates programatically
by loading the ASCII template files to a TStringList object. Then loop
through the lines of the list and change the text programatically. You can
loop through the files in a directory using ppFileUtils.pas calling the
GetFileNamesForDirectory procedure to load the file names.

If you have binary report templates, you'll also be able to convert these
with an extra couple of steps. You can load the binary template file into
ASCII format, modify it, and then save it back to binary as shown in the
example links below. Keep in mind the conversion is performed without
loading the report template into a TppReport.


This example shows how to load reports stored to the ReportExplorer database
tables and convert them to ascii text.

http://www.digital-metaphors.com/tips/EditTemplatesAsText.zip


This example shows how to convert an .rtm file to asii text


http://www.digital-metaphors.com/tips/ConvertBinaryTemplateToASCII.zip



--
Tech Support mailto:support@digital-metaphors.com
Digital Metaphors http://www.digital-metaphors.com


--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com
"Alessandro Federici [RemObjects Software]"