Cross-filtering¶

A click on a bar, a point, a slice or a row filters the other visuals of the dashboard on what it shows. Below, the Île-de-France / Partenaires bar is clicked: its visual dims the rest and shows the selection, and the revenue by quarter now counts those sales only.

A bar selected in Revenue by region and channel; Revenue by quarter shows the selection's figures

It works as soon as the visuals share a FilterContext, as for global filters.

What users do¶

Action	Result
Click an element	It becomes the selection: the other visuals keep its rows.
Click it again	Clears the selection.
`Ctrl` + click in the same visual	Adds the element to the selection, or removes it: Region = Nord or Sud.
`Ctrl` + click in another visual	Adds that visual's selection: (Region = Nord or Sud) and Channel = Web.
Click the ✕ of a selection	Clears that visual's selection.
Click the ✕ of the filter bar's summary	Clears every selection.

An element filters on the dimensions it shows: its category (every axis field), and its series for a chart with a legend. A clicked period (a quarter, a month) filters on that period.

A visual is not filtered by its own selection

It keeps showing everything, dims what is left out, and shows a summary of its selection.

In code¶

Filters.Selections;                       // one CrossFilter per visual with a selection
Filters.SelectionOf(visual.Id);
Filters.ClearSelection(visual.Id);
Filters.ClearSelection();                 // all of them
Filters.DescribeSelections(name => context.GetModel(name).Metadata);

Selections are not saved with the report: they are the state of a session.

In a connector¶

A connector reports clicks and draws the selection; EasyBI does the rest.

// On click (Select is null when the visual is not interactive, as in the designer's preview)
request.Select?.Invoke(new CategorySelection(category, series));

// When drawing: the elements outside the selection are dimmed
var opacity = request.IsEmphasized(category, series) ? 1 : SelectionFilters.DimmedOpacity;

Tables report a RowSelection and use IsRowEmphasized(row). See Writing a connector.