Tableau 2020.1: Dynamic Parameters
Dynamic parameters are finally coming to Tableau! One of the most asked for features of all time is just around the corner.
So let’s take a quick look into how to set them up.
When you go to create a parameter, and set the allowable values to a list, there is now a new section to the right hand side. The old way of building parameters is under the “fixed” radio button.
This new option “When workbook opens” will now allow you to select a field to use. It’s important to note it will only let you select field with the matching data type to the parameter. (In this case the parameter data type is Date so it only lets me select Date type fields, which in my case only returns Month.)
Click ok and that’s it! You’ve created a dynamic parameter.
Behind the scenes, whenever you open a workbook, Tableau will perform a query that will return all the unique values in that field for the entire data set and populate the parameter with that list.
A common use case for this would be to have the dates in a parameter update along with the data, so when that new month rolls around you don’t have to go and fiddle with it!
Good to knows
The order in which dynamic parameters are populated will be based on the default sort of the field. (By default this will be data source order.) So if you want new values to fill in at the bottom rather than alphabetically then simply set the default sort to manual.
Can I use a calculated field?
Yes! You can set dynamic parameters based on calculated fields. So if your data was at the month level but you wanted a parameter to update based on years then just create a calculated field for year and base the parameter off of that.