This blog post was inspired by Ryan Sleeper’s blog on Placeholders in Tableau and this is a short example to get you started.
Ryan explains that placeholders in Tableau offer “some unique flexibility… because each measure on the Columns Shelf or Rows Shelf gets its own Marks Shelf, where the Marks Cards can be edited independently.”
Create a Calculated Field for your Placeholder
First off we have to create a Calculated Field. We hit the small dropdown tab from just above the Data pane and select Create Calcualted Field.
We then name it Placeholder and add the simple calculation min (0). This means that whatever mark you drag onto the separate shelves remains at zero. This might lead to think there is therefore no way to show a deviation in value but don’t forget that divergence can be shown not just through size but also but colour and of course text.
So far so easy. From here we have drag Placeholder onto the Columns Shelf and repeat the process again. In fact the great thing about Placeholders is that you drag as many as fifty onto a shelf. We won’t be doing that today.
Now back to the Placeholders…
Notice that we also now have two Placeholders on the Marks Card shelf.
From here you can drag different measures onto the Marks Card shelf and edit and alter them within the different Marks Cards.
Let’s start by dragging Region onto the Rows Shelf…
Now we can bring SUM(Population 65+) onto the Marks Card. Drag it onto Colour and Label…
Change the Mark type to Circle. You’ll see it change from ‘bar’ to circle and you’ll notice the divergence can be seen (just about at the moment) in the colour of the circles.
We have to now make this all a little more visible and we do this by changing the Size of the Circle. You will also want to change the View if the whole Sheet from Standard to Entire View to get the whole picture.
Those labels outside the Circles also look a little silly out there on their own so let’s get them inside the Circle by changing the Alignment, again on the Marks Card.
You are now going to repeat the same steps on the other Marks Card but this time you can introduce a different Measure – Birth Rate – and use a different type of Mark – text – in this case.
Once you have changed the Mark to Text you might want to change Colour of the text to distinguish it from the other Measures.
Finally remove Placeholder by clicking on the Axis and unticking Show Header.
You can now add this sheet to your dashboard or better still add more Placeholders across your Columns Shelf and populate it with relevant Measures as you see fit.
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