Hi Keith -
There is no specific operator (!=, <>, etc.) to make a filter exclude rather than include values on the URL.
If the filter already exists in your viz and is of type "exclude", you just feed in values (which will be excluded) as you normally would. You could probably create your own parameter-driven expression which does something like this, though:
!Europe (exclude Europe)
+Europe (Include Europe)
You'd feed a value into the parameter, and an expression would parse the input, looking for ! or + at the front. Based on the value it sees, it would use a different control flow to deal with the include/exclude. There are probably some other techniques that I haven't thought of, too.
Hope this helps!
If I understand you correctly:
1. If a dimension in the data source is named FOO
2. And if a filter already exists in my worksheet, which is defined to exclude values for FOO
3. Then a URL of the form ?FOO=bar will actually exclude from the vis those marks for values = "bar" in dimension FOO ?
If this true, then I'm hoping to clarify: the name of the variable to call after the ? in the URL is the name of the dimension itself. And it is not the case that the filter has a unique name which should be called in the URL (e.g. ?FOOFILTER=bar).
Please confirm, thanks!
You got it.
I just tried it, in fact – I have a “Continent” dimension, which I added to the Filter Pane and set as “Exclude”.
When I passed ?Continent=Europe, Europe went away. When I set ?Continent=Asia, no more Asia.
You could probably (quite easily) create a duplicate of the Continent column called “ExcludeContinent”, put THAT on the filter shelf instead as “exclude” and have a specific way to feed in “exclude” values for Continent while leaving the original field alone.
(I haven’t tried this part, so let us know how it goes)