DISCLAIMER: This blog assumes you know the basics of Tableau Parameters.
When you first start out with Tableau, parameter actions seem like an advanced level tech. As it turns out parameters are fairly straightforward but parameter actions didn’t really make sense to me. So the question is how do parameter actions work?
One of my favourite things about Tableau is its interactivity. Being able to change the scope of the dashboard by changing a parameter or filter to me, is peak data visualisation…when the user can fully immerse themselves in the data and explore their own questions.
One of my least favourite things about Tableau are drop-down menus. Although it sounds pedantic, selecting a parameter value from a drop-down menu is just way too many clicks. It also doesn’t help that aesthetically, they detract from the immersion. Really, my favourite dashboards have no menus at all, just buttons and interactive portions of graphs. Does that point look exceptionally interesting? Click on it to find out some more info or drill down to finer detail.
But if you don’t want to use a drop-down menu, what other options do we have?
PARAMETERS
When I first started using Tableau, I had this exact idea but had no idea how to execute it. All I know is that I wanted to change the value of a parameter, but have that integrated in some way with my dashboard. Which led me to find out about parameter actions, but as often is the case, I could not find an explanation of how they worked (which could just be a symptom of my poor Googling ability).
Maybe its because no one has ever considered that parameter actions aren’t as simple for new users, or maybe its just a reflection of my poor Googling abilities, but here is the definitive explanation of parameter actions.
WHAT IS A PARAMETER
Basically, a parameter is a value that you can change. It can be changed manually with user inputs or changed ‘automatically’ with some calculations. But you will notice that as you make more vizzes, if you want some interactivity in your dashboards, you’ll probably use a parameter or two.
HOW DO YOU CHANGE A PARAMETER
Whenever you create a parameter you will most likely have to do two things
- Create a calculated field – Parameters surprisingly cant just be brought into the field of view, so you will first have to create a calculated field with that parameter and then use that calculated field. The best way I can explain this is that parameters don’t really exist physically in the data, theyre more of a data source that gets referenced. Hence, the calculated field allows you to actually bring the parameter in.
- Show parameter – even if the parameter is present is referenced somewhere in your view, the option to change it wont be. As such, you will have to manually select Show Parameter.
From here, you can choose which kind of menu you want…But since the goal of this blog is to explain how to do it without this dropdown menu lets learn about…
PARAMETER ACTIONS
Parameter actions can be added to dashboards or even workbooks, and their sole purpose is to change the value of a parameter. To create a parameter action:
DASHBOARD > ACTIONS > CHANGE PARAMETER
- Source Sheets
- Dashboard that the parameter is located on
- Sheet that the parameter is located on
- Target
- Parameter that you wish to change
- Field
- Refers to a specific field on the sheet
- Aggregation – refers to the aggregation of that specific field
- Changing the selection will
- Keep current value – useful if you want your change to be permanent
- Set value to – useful if you want your change to be temporary
SIMPLE EXPLANATION OF PARAMETER ACTION
If you have a parameter action set up on select, whenever you select anything on that target dashboard or sheet, the parameter action will try to change the parameter value by looking for a field that contains one of the parameter values.
For an alternative explanation, if your parameter had the possible values of CAT or DOG, if any of the fields you click on are DOG, the parameter action would cause the parameter value would change to DOG.
WHAT DOES THE PARAMETER ACTION LOOK FOR
A parameter action looks at the value of the field you set and then if the values match, it changes the parameter to that value. This means that the value that you want to change your parameter to must be contained within whatever you want to click on.
Therefore, the value can either be present in a level of detail field, a dimension, or a calculated field.
BASIC CALCULATED FIELD
The simplest way to have a calculated field contain that value… is to make that calculated field = that value.
ADVANCED CALCULATED FIELDS
IF and WHEN calculations are great for making your parameter values change to different things based on different criteria. As such, rather than having your parameter change to one specific value you can have it change to