So after Ann’s gentle workout for week 6, newly crowed Tableau Zen Master Lorna, hit us with this challenge, and I confess, I struggled. The thought of then having to write this blog about it even brought a little tear to my eye 😦

But here I am, and I will do my best, but I can’t promise I understood everything that went on in this. I truly am amazed at times how some people manage to be so creative and bend Tableau to their will. It really is like #TableauBlackMagic at times!

So I read the challenge through multiple times, played around with Lorna’s published viz, stared at the screen blankly for some time…. I found the University Planning Dashboard viz by Ryan Lowers that Lorna had referenced in the challenge as her inspiration (she’d linked to it from her published viz). I played around with that a bit, although that took a while for me to get my head round too.

I also did a google search and came across Jonathan Drummey‘s blog post : Parameter Actions: Using a parameter as a data source. This provided a workbook and some step by step instructions, so I used this as my starting point. I downloaded the workbook, copied across the fields he suggested and tried to apply his instructions to Lorna’s challenge. But after a couple of hours, it felt as if I was making little progress. I couldn’t figure out whether I needed 2 or 4 parameters to store the ‘list’ data source variables (one each to store the list of selected categories for forecast, the list of selected categories for target, the list of selected forecast values, and the list of selected target values, or one each to store the list of selected categories and forecast values combined, and selected categories and target values combined). Suffice to say I tried all combos, using a dashboard to show me what was being populated on click into all the various fields/parameters I’d built. But it just wasn’t giving me exactly what I needed.

I downloaded the University Planning Dashboard and tried to understand what that was doing. And finally I shrugged my shoulders, and admitted defeat and cracked open Lorna’s solution. When I finally get to this point in a challenge, I try just to ‘have a peak’, and not simply follow verbatim what’s in the solution. I gleaned that I did need only 2 parameters, and that what I had been doing with my attempts with Jonathan’s example was pretty close. It made me feel a bit better with myself.

How things then transpired after that I can’t really recall – it was still a lot of trial and error but I finally got something that gave me the Sales Forecast data and associated select & reset functionality (by this time I’d probably spent 4 hours or so on this over a couple of evenings). Once I’d cracked that, the target was relatively straight forward, so by the time I’d finished on the 2nd day, I had a dashboard that allowed the selections/resets and simply presented the data in a table on screen. I chose to keep that version as part of my published solution, just for future reference (see here). I then finished off the next day, building the main viz.

What follows now, is just an account of the fields etc I used to build my solution. So let’s get going….

Building the Sales Forecast Selector

I’m going to start by focusing on building the left hand side of the viz, setting and resetting the Sales Forecast values for each Category.

We need 2 main parameters to start with:

Forecast Param

An integer parameter defaulted to 70,000. This is the parameter that stores the value of the forecast to set.

Forecast List

A string parameter defaulted to empty. This is the parameter which will ‘build up’ on selection of a category, to store a delimited list of category + forecast values – ie the data source parameter.

Oh, and I also used a 3rd parameter, Delimiter, which is just a string parameter storing a :

The delimiter needs to be a distinct character that mustn’t exist in the fields being used. The Category field nor the Forecast Param field will contain a ‘:’, so that’s fine. But any other unused character would work just as well. Having this field as a parameter isn’t ultimately necessary, but it makes it easy to change the delimiter to use, if the chosen value doesn’t end up being suitable. It was also a field used in Jonathan Drummey’s solution I’d based my initial attempts on.

Now we need to build the viz to work as the category selector.

I simply put Category on the Rows shelf, sorting the pill by SUM(Sales) descending and set the Mark Type to circle. Oh – and I set a Data Source Filter to set the Order Date just to the year 2019.

I also needed the following

• something to colour the circles based on whether the Category was selected or not
• something to use to help ‘build up’ the List parameter ‘data source’
• something to return the forecast value that had been selected against the specific Category

Category Exists in Forecast List

CONTAINS([Forecast List], [Category])

If the Category exists within the Forecast List string of text, this field will return true, and indicates the Category has been ‘selected’. This field is added to the Colour shelf, and the colour needs to be adjusted once parameter action has been applied to distinguish between true & false.

Add to Forecast List

if [Forecast Param]<>0 THEN
[Forecast List] +
[Category] + ‘_’ + STR([Forecast Param]) + [Delimiter]
ELSE ”
END

If the entered Forecast value isn’t 0, then append <Category>_<Forecast Value>: to the Forecast List parameter. Eg if the Sales Forecast value is $50,000 and Technology is selected, then Technology_50000: is added to the existing Forecast List parameter, which has started as blank.

If the Sales Forecast value is then changed to $10,000 say, and Office Supplies is selected, then the Forecast List parameter will become

Technology_50000:Office Supplies_10000:

This Append To Forecast List calculated field is used in conjunction with the Forecast List parameter within a Parameter Action on the dashboard to make all the ‘magic’ happen. The Append To Forecast List field must be in the view to be available to the parameter action, so it is added to the Detail shelf.

When a circle is selected the Append To Forecast List field is used to ‘set’ the Forecast List parameter, subsequently building up a string of Category_Value pairs.

Finally, on hover, the Category and the value of the selected sales forecast at the time must be visible on the Tooltip. To get the value at the point of selection, which isn’t necessarily the latest value visible in the Sales Forecast parameter displayed on screen, the following field is required:

Current FC Value

INT(if contains([Forecast List],[Category]) then
REGEXP_EXTRACT([Forecast List],[Category]+”_(-?\d+)”)
end)

This manages to pull out the number associated with the Category, so in the above example, would return 50000 for Technology and 10000 for Office Supplies.

This field has custom formatting applied : ▲”$”#,##0;▼”$”#,##0 and is added to the Tooltip shelf.

RegEx is a concept I have yet to really crack, so there is no way I’d have come up with the above on my own. I think it’s looking for the named Category followed by Underscore (_) followed by either 1 or no negative sign (-) followed by some numbers, and returns just the numeric part.

Finally, the circles shouldn’t be ‘highlighted’ when selected on the dashboard. To stop this from happening a calculated field of True containing the value True, and a field False containing the value False are required. These are both added to the Detail shelf, and a Filter Action is then required on the dashboard setting True = False. This is a technique that is now becoming a familiar one to use, having been used in earlier #WOW2020 challenges.

So my ‘selection’ sheet looks like

and when added to the dashboard, the parameter action looks like :

with the filter action looking like :

At this point, I’d suggest using a ‘test’ dashboard which contains the selection sheet, displays the Forecast List and Forecast Param, and has the dashboard actions described above, applied to get an idea of what’s going on when a circle is selected, and the values of the Forecast Param changed.

The final part to this set up, is the ‘reset’ button, which when clicked on, empties the Forecast List parameter.

Create a new sheet, change the Mark Type to Text, and on the Text shelf add the string ‘↺’. I simply typed this ‘into’ a pill, but you could create a calculated field to store the ‘image’, which isn’t actually an image, but a special string character, that I got off my favourite ‘go to’ unicode characters website.

You then need a calculated field

Forecast List Reset

”

that just contains an empty string. This is added to the Detail shelf.

Put this sheet on the ‘test’ dashboard, and create another parameter action

This takes the value out of the Forecast List Reset field and sets the Forecast List parameter, subsequently resetting the list to an empty string on click.

Verify this is all working as expected.

Building the Sales Target Selector

Subject to Sales Forecast selector working as expected, then apply exactly the same principles to create the Target selection sheet and associated parameters.

The only slight difference with the fields used in the Target selection is:

Add to Target List

if [Target Param]>0 THEN
[Target List] +
[Category] + ‘_’ + STR([Target Param]) + [Delimiter]
ELSE ”
END

This just applies the addition to the list if the entered target is a +ve number (ie > 0), rather than not 0 as in the forecast selection.

The Target also needs to be displayed on the Tooltip, and this time there is a default target value that should be displayed, even when no selection has been made. For this I created

Target

IF ZN(MAX([Current Target Value])) = 0 THEN
MIN(IF [Category]= ‘Furniture’ THEN 270000
ELSEIF [Category]= ‘Office Supplies’ THEN 260000
ELSEIF [Category]= ‘Technology’ THEN 250000
END)
ELSE MAX([Current Target Value]) END

which was formatted to a currency of 0 decimal places, prefixed by $. This was added to the Tooltip shelf.

At this point, you should now have both the ‘selection sheets’ working on the dashboard, so we can now focus on building the main viz.

Building the Bar Chart

Rather than building the bar chart, I first decided to build a tabular view that simply presented on screen all the bits of data I needed for the bar chart, this being

• Sales value per Category (simply SUM(Sales))
• Sales Forecast value per Category (ie Sales + selected Forecast value)
• Selected Sales Target value per Category (this is the Target field described above)
• % Difference between Sales & Target
• % Difference between Sales Forecast & Target

So I created the following additional calculated fields:

Forecast

SUM([Sales]) + MAX([Current FC Value])

formatted to currency prefixed with $ set to 0 dp.

Forecast vs Target Diff

([Forecast]-[Target])/[Target]

custom formatted to ▲0%; ▼0%

Sales vs Target Diff

(SUM([Sales])-[Target])/[Target]

also custom formatted to ▲0%; ▼0%

Adding the table to the ‘test’ dashboard allows you to sense check everything is behaving as expected

Now its just a case of shifting the various pills around to get the desired view. Ensure at least one Sales Forecast Category has been selected, to make it easier to ‘see’ what you’re building.

Lorna stated the target should be displayed as a Gantt mark type, with the sales and the forecast displayed as bars. This means a dual axis chart is required, with sales & forecast on one axis and target on the other.

To get Sales and Forecast onto the same axis, we need to add Category to the Rows (sorted by Sales desc) and Measure Values to the Columns, filtering to only the two measures we need.

Set the Mark Type to bar, and add Measure Names to both the Colour and the Size shelf.

Adjust colours and sizes to suit.

You might have something like

where the measures are ‘stacked’, so the bar is the length of the Sales then the length of the Forecast. We don’t want this, so need to set Stack Marks to Off (Analysis menu -> Stack Marks -> Off).

Add all the necessary fields to the Label shelf and format accordingly (you may need to widen the rows to make the labels show against each row).

Note – in my solution I created some fields to make the opening & closing bracket around the Forecast v Target Diff value only show when a Forecast had been selected, however in writing this blog, I realise it was simpler just to change the formatting of the Forecast v Target Diff to add the brackets around the number. The custom formatting was changed to : (▲0%); (▼0%)

Adjust the Tooltip to suit too.

Now add Target to Columns alongside Measure Values. Set to Dual Axis and Synchronise the axis. Reset the Measure Values mark type back to bar if needed, and set the Target mark type to Gantt.

Remove Measure Names from the Colour and Size shelf of the Target marks card. Untick Show Mark Labels too. Adjust the colour of the mark to suit, and you should pretty much be there now…

Tidy up the final bits of formatting, removing/hiding the various axis, labels, gridlines etc etc.

When this is all put together on the dashboard, you might need to fiddle about a bit with layout containers to get the bar chart lined up with the Selector views.

And with that I’m done! My published version is here, along with the ‘check’ dashboard I used to sense check what was going on, as I’m sure if I ever looked at my solution again, I’d struggle to understand immediately 🙂

Once again, I just want to acknowledge those that manage to create this magic with Tableau. I applaud you!

Happy vizzin’!

Donna