dishwasher drain line location

how important is it to run the dishwasher drain into the waste line ...
BELOW the sink drain trap as opposed to ABOVE...

In this case, the connection now goes into the waste line between the sink tail piece ABOVEthe inlet side of the trap because there is not enough room to connect BELOW the outlet side of the P-trap .

where the P-trap is located ,the discharge side goes almost immediately thru the rear cabninet wall and drywall leaving less than 2 in. of the waste line exposed . Insufficient room for DW connection
Could this be cause of homeowner complaint of smell from kitchen sink.

Also does Alberta Can. code allow this.... thanks Corney

It should be as it is not on the outlet side of the trap, this would cause sewer gas to enter the dishwasher.

dishwasher wye is the key word combination to web search with to see images on the web. You will see the images as above and also with a hose looped high (no air gap) going into a Wye.

The dishwasher is NEVER connected to the waste line between the trap and the wall. In other words it is IMPORTANT NOT TO DO IT. Doing that COULD, but not necessarily would, insure that sewer gas odors entered the room through the dishwasher. If it is connected between the sink and the trap, then it is NOT the source of any sewer gas odors.