Add support for column specific fillna to viz

[xrmx]

Fix #3029

[xrmx]

not needed

[coveralls]

Coverage increased (+0.06%) to 69.439% when pulling 7458aa62b9a7b95b262de584958f7d606d2c0868 on xrmx:typedfillnae into 6045063 on apache:master.

[xrmx]

@mistercrunch any chance you can review this please?

[mistercrunch]

I'm not sure whether we want to systematically replace NULL with <None> and empties with 0. I understand the use case but people may not want that in their existing charts....

[xrmx]

Maybe i wasn't clear but right now my visualization are not working with superset because NULL is not coerced to '0' (string) anymore as it was on caravel. So that fixes a regression for me :) Said that I don't think <None> is worse than 0 for text, we can change that to <NULL> so that would be more clear for SQL aware people. The surrounding <> are just a trick to have it show before other letters after sorting. For other types the 0 is actually hardcoded so I am not changing any behaviour.

UPDATE: maybe i can use a preceding space before NULL to be more SQL-like

[coveralls]

Coverage increased (+0.06%) to 69.442% when pulling 9202d80f389b7368dbf3bc4d26392235cfaa2227 on xrmx:typedfillnae into 6045063 on apache:master.

[coveralls]

Coverage increased (+0.05%) to 69.342% when pulling 2097b55c46c8f2479caa5704922cd6857d829a31 on xrmx:typedfillnae into c944c61 on apache:master.

[coveralls]

Coverage increased (+0.05%) to 69.342% when pulling 2097b55c46c8f2479caa5704922cd6857d829a31 on xrmx:typedfillnae into c944c61 on apache:master.

[xrmx]

@mistercrunch any hint on how we can move this forward?

[ToonoW]

It make sense what @mistercrunch say. We should not use 0 and ‘NULL’ replace <null> in sample way, it will make misunderstanding in some situation.

Simple and Difficult Problem. : (

[rumbin]

Just wanted you to know that I would also love to see #3029 fixed in the next release, as some of our pivot tables also don't work any longer when upgrading from 0.15.4 to 0.19.1.

So, thanks @xrmx for your efforts!

[coveralls]

Coverage increased (+0.05%) to 70.112% when pulling 1c25fe4 on xrmx:typedfillnae into f829b48 on apache:master.