/diy/ - Do It Yourself

I have to install three light fixtures similar to picrel one after the other (all three in a straight line).
1- Each one has cable holes and connectors on both sides. Does that mean I can just kind of daisy chain them, meaning that only one fixture is connected straight to the source, then the second one gets fed from a cable that comes out of the second hole of the first fixture, and so on? As far as I know that’s not a good idea but maybe I’m wrong since that’s how the installation was started.
2- I’m not familiar with the color scheme of the wiring inside of the light fixtures. The wires besides the ground wire are black and if I recall correctly while. The wires I need to connect to them, brown and blue. Which one goes where? Do they need to be alternated in any way from fixture to fixture? I ask because the person who started the installation connected black with blue in one fixture and with brown in another other one.