Is that possible or just buy a complete new slider and replace the whole deal? The glass in cracked.

While possible, it is likely that the frame will be different. Also, a lot of units are a custom size, making replacement difficult.

It might be better to get a new unit installed that is of the current technology with multi-pane low-e glass.

It can be done if the maker is currently making that type of framework and you have the model number detail OR very exact measurements.

If the unit is on the 10 or more years older it may be worth replacing the entire unit with a newer model as they have better gases and coatings.

"Doors and Windows are holes in the wall you throw money through" so try to get the best compromise of costs.

If your sliding door is anything like mine, the "glass" is actually a sandwich of two panes of glass, sealed at the edges with an asphalt-like compound, with a gap between them. This gap is filled with some inert gas (argon?) that provides better insulation than air. You can buy, or have made, one of these sandwiches sized to your measurements. I don't think there are standard sizes, but there is some room for play in the fitting so you might be able to find an appropriate one already made up.

In my case, they fit into an aluminum frame with rubber-like gaskets, secured by screws at the corners. Getting the glass into the frame without mangling the gasket can be a challenge. My experience is that it is better to do each of the four sides of the frame separately than to try to squeeze it into a partially assembled frame.

I'm sure your local glass shop can give some advice. Weed whackers busting patio sliders is a very common occurrence.

If you can find the mfg label, usually in the head jam area, they may be able to help you.
Last time I ordered a window insulated glass panel there was a long lead time from my local glass shop.
If your unit has some age on it, you may be dollars ahead to replace with new. My son liked the composite framed one we put in his house.

I had a large table umbrella bang into my window during a storm. It shattered the glass.

A local glass company came out the next day and took measurements.

Two days later they installed the glass.

It was a small fraction of the price of a new slider.

It was a sealed double pane window.

Look in one of the corners on the glass. Anderson has the info there for replacement. If it is an Anderson.
There might be info on the top of the door itself if its taken out.