Publish a View as a Widget¶
Publishing views as widgets is a deprecated feature and it may be removed in future major versions of the Denodo Platform.
The section Features Deprecated in Virtual DataPort 7.0 lists all the features that are deprecated.
To create a widget, click Widget on the File > New > Data service menu, or right-click on the Server Explorer and click Widget on the New > Data service menu.
The dialog to create new widgets has tree tabs:
Widget configuration: in this tab you have to provide the following:
Widget name: name of the new widget.
Display name: name that will be displayed to the users of the widget.
Database and Element to publish: select the element/stored procedure you want to publish and its database.
Enable Help Mode: if selected, the Help Mode of the widget will be enabled and users will be able to switch to it. This mode will display basic instructions of how to use this widget. You can customize these instructions by clicking on Edit help mode content.
Custom Table Events (only for JSR-286 portlets): select this option to enable the Full Table JSR-286 complex event.
Increase the performance of the JSR-286 portlets by not selecting this option (see section Export to JSR-168 or JSR-286 Portlet for more details).
Connection parameters: configure the connection parameters used by the portlets and the auxiliary Web Services to connect to Virtual DataPort (section Auxiliary Web Services explain what the auxiliary Web Services of the widgets are)
Chunk Size. The results obtained by executing a sentence can be divided into blocks (chunks), so the Virtual DataPort Server does not have to wait until a sentence ends, to send the processed tuples to the portlet or the auxiliary Web service.
This parameter establishes the maximum number of results that a block can contain.
When the Server obtains enough results to complete a block, it sends this block to the client and continues processing the next results.
Chunk Timeout. It establishes the maximum time (in milliseconds) that the Server waits before returning a new block to the portlet or the auxiliary Web service. When this time is surpassed, the Server sends the current block even if it does not contain the number of results specified in the Chunk Size parameter.
If Chunk Size and Chunk Timeout are 0, the Server returns all the results in a single block. If both values are different from 0, the Server returns a chunk whenever one of these conditions happen:
- The chunk is filled (Chunk Size)
- Or, after a certain time of not sending any chunk to the client (Chunk Timeout).
Query Timeout. Maximum time (in milliseconds) the server will wait for the termination of a query. If its value is 0, it will wait indefinitely until the query finishes.
Enable Pool. Enable the use of the connection pool. In production environments, the use of the connections pool is strongly recommended.
Initial Size. Initial number of connections to be opened in the connection pool.
Max Active. Maximum number of connections in the pool. A negative value means there is no limit.
Metadata: select the target folder of the Web service and provide a description for it.
After configuring everything, click on Save to create the widget. The Tool will display the “Widgets container status” table (see Widgets Status Table) that lists the existing widgets.
This table provides the following information and actions for each widget:
- Name of the widget.
- Export. Contains buttons to export the widget to different widget technologies.
- Status indicates whether the auxiliary Web Service is deployed in the embedded Web container. If it is deployed, but changes have been made to the widget configuration, this is indicated by an “*”.
- Context path. If the auxiliary Web Service is deployed in the embedded Web container, contains the path to the service.
- Deployment. Contains links to deploy / redeploy / undeploy the auxiliary Web Service of the widget.
- Properties. Click on Show to display the properties of the widget.
You can also open the “Widgets container status” dialog by clicking Widgets container on the menu Tools.
To obtain the information provided by this dialog from an external
application, invoke stored procedure
WEBCONTAINER_ELEMENTS (see section WEBCONTAINER_ELEMENTS of the VQL Guide).
To open an existing widget, double-click on it, in the Server Explorer or click on its name in the “Widgets container”. Then, you can:
Change the view/stored procedures to publish.
Change the settings of the widget.
View the VQL code that generates the widget by clicking View VQL. This dialog has the same options as the “View VQL” dialog of views (see section View the VQL of an Element).
The VQL statements of this dialog correspond to the widget configuration stored in the Server and it does not reflect the current modifications.