Widgets should be able to persist some parameters (eg. viewDataTable)

[julien]

The user could want to save the default appearance of his widgets. Currently only the widget name is saved. But it would be nice to also save the "state" of the widget, in this case defined by the "viewDataTable" parameter.

For instance he can decide to view getCountry with a pie-chart by default. Parameters would be stored in the JSON as an array.

see also #380

[vipsoft]

In #791, haas raises the issue that filter_limit doesn't persist switching between a widget's chart types:

If I preconfigure the widget to filter_limit=8, this value is taken into account first. If I use the dataTableFooterIcons to switch to a different view I only need to click on the bars and than back to table view and the filter limit is reset to 3. Expected -> The original filter limit should be kept.

[vipsoft]

We also need a getter to resolve #789.

[matt]

(In [2497]) Fixes #90 Dashboard now remembers which View type the widgets were set to (table, goals, all columns, pie chart, vertical chart, etc.) and saves this information in the dashboard layout.

[JulienM]

Should this ticket be reopened now that #1820 is implemented?

[matt]

Good point, it is now included in: #1915