Customs Parameters

rbuser

Hello,

I would like someone to calrify something for me. After a lot of tinkering
with RBServer Edition, it seems that I have to set SessionParameters and
ReportParameters in their corresponding OnValidate Event? Example:

procedure TForm1.rsServer1ValidateSessionParameters(Sender: TObject;
aParameters: TppParameterList; var aIsValid: Boolean);
begin
{validate the parameter names}
aIsValid := (aParameters.InList('Parameter1') and
aParameters.InList('Parameter2'));
if aIsValid then begin
rsServer1.SessionParameters['Parameter1'].Value :=
aParameters['Parameter1'].Value;
rsServer1.SessionParameters['Parameter2'].Value :=
aParameters['Parameter2'].Value;
end
end;

Is this correct? It seems to be the only way it actually works.

Thank you,

Tracy McClarnon

rbuser

Does anyone have a simple example of a report server that receives session
parameters and report parameters from a client application? I know the demos
do this, but I feel that they are a bit too complicated in getting the point
across. Any help would be greatly appreciated. It would be even better if
you included the server and client code.

You can send your examples to tmcclarnon@mccallie.com.

Thank you

nardmoseley

Perhaps you are missing a conceptual understanding of the architecture.

---------------------------------------------------------------------
Article: Overview of Custom Parameters Architecture
---------------------------------------------------------------------


I. SessionParameters
--------------------

1. Each time a client communicates with the server, the client must send the
session id.

2. Each time the server receives a client request, it authenticates the
request. These are the possible cases:

a. No session id specified or invalid session id specified
Validate the session parameters passed from the client. If valid, then start
a new session and generate a new session id. The session id will passed
back to the client.

b. Existing session, no session parameters specified or same session
parameters specified.
Use the session parameters for the existing session.

c. Existing session, new session parameters specified.
Validate the new session parameters.

3. The SessionParameters are always passed to the custom parameters related
events.

a. For the TrsServer events such as OnValidateSessionParameters, the session
parameters are passed in the "aParameters" parameter.

b. For the TrsReportVolume events, there is an "aEventParams" parameter that
contains a SessionParameters property (i.e. aEventParams.SessionParameters).
Note that the aEventParams object contains a different set of properties
depending upon the report volume event. The specific properties are
documented in the online help


II. ReportParameters
--------------------

ReportParameters are only relevant to a request for a specific report. The
relevant ReportVolumeEvents that are provided are: OnGetReportParameters,
OnValidateReportParameters, and BeforePublishReport. Each of these events
passes an "aEventParams" object to the event-handler that contains the
SessionParameters, ReportParameters, and other information. Again, note that
the aEventParams object contains a different set of properties depending
upon the report volume event. The specific properties are documented in the
online help.

The ReportParameters passed from the client are automatically assigned to
the TppReport.Parameters property. In the server custom parameters demo, the
ReportTemplateVolume.BeforePublishReport event is implemented to add the
session parameters to the TppReport.Parameters.



--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Thank you for the response, but I am still encountering a few problems:

1. Whenever I call GetReportParameters from the client, I always receive 4
parameters named "ppParameter1".."ppParameter4" even though I have given
totally different names to the TppReport.Parameters via the ParametersEditor
on the server.

2. GetSessionParameters returns exactly the same Parameter Names I gave in
the SessionParametersEditor on the server. This is Fine, it just confuses me
when #1 above doesn't work the same way.

rbuser

Are these statements true?

1. TrsServer.SessionParameters values aren't automatically set to the
SessionParameters values received from the client.
2. TppReport.Parameters values aren't automatically set to the
ReportParameters values received from the client.

Thanks again for your time...

nardmoseley

1. True. TrsServer is a singleton - there is only one. There can
simultaneously be many clients connected to the server. The
SessionParameters sent from the client can only be accessed in the Server
and ReportVolume events that I mentioned in the article. The Server events
only fire when a new session id needs to be allocated. They do not fire for
each client request received from the server. In other words, session
authentication occurs only once - at the beginning of the session.

2. False. The ClientReport.ReportParameters are assigned to the
Report.Parameters prior to calling the ReportVolume.BeforePublish event.

It would help me to know what you are trying to accomplish...



--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com

rbuser

What I am trying to do is run a report from an IntraWeb application.

I need to pass parameters to the server (that is running as a service on a
seperate machine) to initialize query parameters before they are opened for
the report. I have placed a TrsWebTier inside my IntraWeb app and am trying
view the report in my web browser. I can access the report perfectly using
TrsClientReport, but I am having difficulty accessing the report via the
TrsWebTier comp.

Does this make sense?

nardmoseley

I recommend that you try to approach this incrementally:

1. Build a simple ClientReport application that uses custom parameters
(sounds like you may have already have done this).

2. Build a simple WebTier application using a Delphi WebDugger application.
(i.e. no IntraWeb).

3. The final step would be to introduce the IntraWeb piece.

Keep in mind that the ClientReport is persistent - its property values
reflect the current SessionID, SessionParameters, ReportParameters being
used. The WebTier is more like a server. It simultaneously handles request
for many "web sessions". A web session is NOT the same as a report session.
Each web session can however cache information about the report session.

report server
sessions

webtier
web sessions


--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Thanks for all your help! One more question...

Should I have 3 applications? A report server(Service), WebTier(ISAPI), and
a client (IntraWeb)?

nardmoseley

I honestly do not know whether you should have separate WebTier(ISAPI) and
(IntraWeb) applications or just use the WebTier component within the
IntraWeb application. I do not have any real experience with IntraWeb.

Try to spend some time with the WebTier custom parameters demo. Read all of
the comments in the code. You need to understand that there are hidden
parameters used in the html forms. Run the example and perform a view
source on the generated html forms.



--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com