Polaris: use of the Active Naming and Grid API of PageBox PageBox

ActiveNaming Grid API Coordinator Presentation Polaris A Polaris B Download



Polaris is a simple application developed to test and illustrate the ActiveNaming and Grid functions. For more information about the ActiveNaming and Grid functions read the Grid document.

Polaris is made of two parts:

There are two versions of Polaris:

PageBox use

The diagram shows an example of configuration:

The Polaris Web service and the Polaris client can be published on different repositories:

Polaris A only implements the orange part:

Polaris A uses the ActiveNaming Web service embedded in PageBox.

Polaris B uses the Grid API


A Repository


A PageBox

The Web service and the client Web application can retrieve the PageBox that installed them, the controlling PageBox.

The Web service Web application calls the ActiveNaming instance of its controlling PageBox to register an object that contains:

The Web service Web application uses the SetKeyRange method of the ActiveNaming Web service and can set a different object for each Web service.

The client Web application calls the ActiveNaming instance of its controlling PageBox to get the list of possible Web service instances. It uses the GetCandidate method of the ActiveNaming Web service.

Coordinator API

The Polaris client part is designed to be used in combination with something that authenticates the user and something that commits the changes. These entities are typically other controls, however Polaris makes no assumption about the way they can be implemented.

The page designer adds the Polaris, the authentication and the commit control to its page.

It can define which ID Polaris will use to retrieve authentication information and the ID of the transaction requestor. Here is an example of Polaris definition in an ASPX page:

<%@Register tagprefix="polaris" Tagname="shoppingBasket" src="ShoppingBasket.ascx" %>


<polaris:shoppingBasket runat="server" TitleCss="map-title" StatusCss="timestamp"

CopyrightCss="copyright" MinWidth="500" MaxWidth="500" DgHeaderCss="datagrid-header"

DatagridCss="datagrid" DgAltCss="datagrid-alt" Css="map-table"

LoginID="Login" SourceID="Commit" ID="Basket" Timeout="0"


WSArchive="PolServer.zip" WSName="ShoppingOrder" Location="Eden" />

This definition is divided in three sections:

  1. Style definition: the user defines here the CSS classes to use to display the different elements of the Polaris control. We presented such definitions in the Control and the GoogleControl documentation

  2. Coordinator definition: the user defines here the ID of the Polaris control, the ID of the authentication source (LoginID), the ID of the transaction source (SourceID) and if the Prepare result should be cached (Timeout). See the Coordinator documentation for more information.

  3. ActiveNaming definition: the user defines here the Repository where the Web service should be deployed from, the Web service name and archive. The user also defines the client location used for location-dependent routing.

The Polaris control first registers for transaction commit coming from sourceID:

PageBoxGrid.TransactionCoordinator.Subscribe(sourceID, Session.SessionID, ID, this, timeout);

this is the callback object that the Polaris control provides to get notified about transaction commit. This callback object implements the Transaction interface. When the control whose ID is sourceID commits the transaction, the Coordinator first invokes the Prepare method.

The Prepare method:

  1. Get the authentication data from the Heap (with a LoginID source)

  2. Uses the ActiveNaming Web service to retrieve the available Web service instance.

  3. Selects a Web service instance depending on the request data and the instance location

  4. Returns true if it found an active and suitable Web service instance

Then the Coordinator invokes the Commit method that invokes the selected Web service instance.

To demonstrate the use of the Coordinator the Polaris client contains

Grid API

The Web service of Polaris B

The Polaris B client


The Polaris documentation includes:

2001-2004 Alexis Grandemange. Last modified .