This week, Sean decided to revisit a challenge from 2017, week 12, which was originally posted by Emma Whyte, one of the #WorkoutWednesday founding coaches.
I’ve been completing the #WOW challenges since their inception, so had the original solution already published to my Tableau Public.
Back then, parameter actions didn’t exist, so I decided to build this latest version using them instead of the parameter dropdown list included in the original requirement.
Building the basic viz
Create a new parameter to capture the Sub-Category we want to highlight
pSubCat
string parameter defaulted to ‘Bookcases’.
(NOTE – if I wanted to use a drop down for the user selection, I would instead have set this parameter to be a list populated from the Sub-Category field when the workbook opens).
I can’t always recall quickly the positioning of all the fields I need to build a treemap, so I started by simply double clicking the fields I needed in turn : Category, Sub-Category, Sales to add them onto the canvas, and then selecting the TreeMap icon in the Show Me tab to reposition the fields as required.
Then move the Category field from Text to Detail.
Colouring the blocks
The requirement is to show the selected Sub-Category in one colour, but also show a graduated colour palette for the non selected Sub-Categories.
First, let’s identify the selected Sub-Category.
Show the pSubCat parameter on the canvas. Then create
Is Selected Sub Cat
[Sub-Category] = [pSubCat]
Change the Sales pill on the Colour shelf from continuous (green) to discrete (blue). This will result in a rainbow of colours
Then add Is Selected Sub Cat to the Detail shelf. Then click on the icon next to the pill that indicates it’s on the detail shelf, and change it to Colour, so 2 fields are now on the Colour shelf.
Move the Is Selected Sub Cat field on the colour shelf so it is listed above the Sales field on the colour shelf. The selected sub-Category should now be highlighted, and the other blocks are graduated.
However, the highlighted sub-category is ‘separated’ from the Category block it belongs in. To resolve this, change the Is Selected Sub Cat field on the colour shelf so it is an Attribute. By setting this, the treemap is now only dividing itself by the Dimension fields of Category and Sub-Category.
Format the Sales field to $ with 0dp, and update the Tooltip as required.
Create the sheet title
Create a new fields
Selected Sales
{FIXED:SUM(IF [Is Selected Sub Cat] THEN [Sales] END)}
format to $ with 0dp and add to the Detail shelf.
Update the title of the sheet to reference the pSubCat parameter and the Selected Sales field and format as desired.
Add the interactivity
Add the sheet to a dashboard ,then add a dashboard parameter action
Set Sub Cat
On select of the treemap sheet on the dashboard, set the pSubCat parameter, passing in the value from the Sub-Category field. When the selection is cleared, keep the current value
However, when the treemap is clicked, the selected block gets ‘highlighted’ and the rest fade. To prevent this, create a new field
HL
‘dummy’
and add to the Detail shelf of the Treemap sheet. Then create a new dashboard Highlight action
Deselect
On select of the Treemap sheet on the dashboard , target the same sheet with the HL field only
As all marks have this HL value set, this has the effect of actually highlighting all marks ‘on click’ rather than just the actual one clicked, so making it look like nothing is actually highlighted.
And that should be it. My published viz is here.
Happy vizzin’!
Donna
Donna + DataViz 