No Data vs. No Selection - what's the difference?

[KateHowlett]

Hello,

I'm fairly new to Dashboards so apologies if this is a silly question. I've read the 'Configure an element' docs about three times and I'm still not sure how this is supposed to work, or if I'm expecting the wrong things. This in particular:

• No data—For data-driven elements, configure a label that displays when there is no data to render on the element. By default, an element in this state displays the No Data label.
• No selection—When elements are configured to render only when a selection is made using the Render only when filtered option, you can configure how the element displays before rendering. By default, the title of the source element or elements from which selection is required is displayed. If the title is not available, the source elements name is shown instead.

I have several 'Details' elements. When I click on a map I have layer actions that filter the layer to show only the area selected (I'm working with school catchments layers). In some cases there are not school catchments for a particular age range.

I would expect that if a selection is made, but there is no data - because there is not a school for that age range in the selected area, that the 'No data' label would be displayed e.g. if there is no selection on the map all catchments say 'Please select the map to find out more' but if there is a selection on the map, but no junior school, it would say 'There is no junior school in this area'.

N.B. If I don't set 'Render only when filtered' it shows the first element in the unfiltered list which is exceptionally unhelpful because then it just always says 'XYZ Junior School'.

But that doesn't seem to be how it works, it only ever displays 'Please select the map to find out more.'

Am I making the wrong assumptions about how it works, am I using it wrong, or does it just not make a lot of sense?

Thanks for any insight you can provide 🙂

[Neal_t_k]

If I am following correctly, how you explain it should be how it works.  To clarify, If you have 'Render only when filtered' toggled on, it only ever shows 'Please select the map to find out more.'?  If that is true, that would point to a selection configuration issue, because it would mean a selection is never occurring, so no data ever renders.  Are you using a field to field selection or a spatial selection? and do you have multiple selectable layers on the map  i.e. are you inadvertently making a selection on a layer that isn't connected to the schools instead of the catchment layer?   Also check if you have category selectors and map layer actions, it is possible that those conflict intended actions.   

[KateHowlett]

Hi Neal,

So on the map element's Layer Actions tab I have the below:

Then, on the specific layer, Junior School Catchments (there's always data for the other two layers, so they don't present an issue)  I have the below:

So when a situation like the below arises, where I have a primary school and a secondary school, but no junior, I would have expected to see the message 'There is no Junior School in this area'. Because there is a selection, but no data.

Sorry, I really should have put all these screenshots in the main post!

Thanks for your time 🙂

[Neal_t_k]

Not sure the exact reason without being able to explore the data...but I suspect your three catchment layers are interacting in way that aren't expected, or each of your catchment layers does not cover the entire area of interest and e.g.  

How are your catchment layers configured? In the screenshot provided, it appear the Junior Catchment is not  selected at all so you are seeing a not selected message.  Are all the catchment layers the same and overlap exactly and just have different attributes that indicate primary, secondary, etc. or are the like a puzzle, mosaic. i.e. Does the Junior catchment for instance have holes in it where Junior schools do not exist? 

If you can a solution might be to union the 3 catchments into one feature service and then for each row have a field for Primary: True/False Secondary: True/False and Junior True/False.  and adjust the indicators accordingly. That way a selection will for sure trigger on all three indicators. 

If you still want 3 separate layer, and there are holes in it, you would have to fill in the holes and attribute the catchment to indicate it contains no Junior schools.

If this were me, I would start over with a full catchment layer, add 3 new fields (Primary, Secondary, and Junior) and attribute them with True/False according to the schools that fall within their boundaries. Then use that as your selecting layer.