Web Client 8.0.2



Interface to be implemented to listen to DynaGrid events comprehending notifications of changes in the shown values and, in case pagination is active, changes in the number of total logical pages.
Events for this listeners are executed synchronously with respect to the code that generates them.
Note that it is not necessary to implement all of the interface methods for the listener to be successfully passed to the DynaGrid#addListener method.


new DynaGridListener()

This is a dummy constructor not to be used in any case.




Event handler that receives the notification that the number of logical pages has changed. The number of logical pages can grow or shrink because of addition or removal of rows and because of changes in the logical page size setting. By implementing this method it is possible, for example, to implement a dynamic page index to allow direct jump to each logical page.

Name Type Description
numPages Number

The current total number of logical pages.


onVisualUpdate(key, visualUpdate, domNode)

Event handler that is called by Lightstreamer each time a row of the grid is being added or modified. By implementing this method, it is possible to perform custom formatting on the field values, to set the cells stylesheets and to control the display policy. In addition, through a custom handler, it is possible to perform custom display actions for the row, by directly acting on the DOM element containing the grid row.
This event is also fired when a row is being removed from the grid, to allow clearing actions related to custom display actions previously performed for the row. Row removal may happen when the DynaGrid is listening to events from Subscription instance(s), and the first Subscription it listens to is a COMMAND Subscription; removal may also happen in case of AbstractWidget#removeRow or AbstractWidget#clean execution and in case of destruction of a row caused by exceeding the maximum allowed number of rows (see DynaGrid#setMaxDynaRows).

This event is fired before the update is applied to both the HTML cells of the grid and the internal model. As a consequence, through AbstractWidget#updateRow, it is still possible to modify the current update.
This notification is unrelated to paging activity. New or changed rows are notified regardless that they are being shown in the current page or that they are currently hidden. Also, no notifications are available to signal that a row is entering or exiting the currently displayed page.

Name Type Description
key String

the key associated with the row that is being added/removed/updated (keys are described in AbstractWidget).

visualUpdate VisualUpdate

a value object containing the updated values for all the cells, together with their display settings. The desired settings can be set in the object, to substitute the default settings, before returning.
visualUpdate can also be null, to notify a clearing action. In this case, the row is being removed from the page.

domNode Object

The DOM pointer to the HTML row involved. The row element has been created by Lightstreamer, by cloning the template row supplied to the DynaGrid.