I was using Excel the other day and used the conditional formatting rules to style some cells based on a condition. If you have never seen or used them they look like this:
They are pretty handy for a quick idea on the state of your data. Looking at QGIS I thought to myself “Wait!? Why not do that in QGIS too. That would be pretty neat”. And with that here it is, finally!. Conditional formatting rules for QGIS attribute table.
You can control the font style, color, background color, even custom icons based on QGIS symbols. The buttons at the top give you access to quick styles which you can tweak more with the other options.
The conditions are just normal QGIS expressions. Use the special variable @value to refer to the current cell value. As they are normal QGIS expressions you can reference the other fields in the expressions.
(Click the GIF for a better view)
So go nuts. I would love to hear any feedback if you use it. Try it out in the next nightly dev build.