It can be repaired, but you'd need to find someone who is a bit handy with "repairing" parts rather than modern technicians who are only apt at replacing parts.

The plastic section is probably not a good idea to repair, it could be done but would need a metal insert of the correct diameter to prevent the pipe collapsing when you join it together, you would then need the correct size rubber pipe to slip over the outside with ideally at least 3 inches on either side and 2 or 3 correct size jubilee clips on either side too.

The only problem doing this is you won't have a "knuckle" of any description to prevent the pipes coming apart, hence the need to make sure plenty of pipe is inserted and enough jubilee clips are used to prevent this.

It's not ideal, and if i'm being honest if you are unsure about doing any of it then forget it, you need to know enough about repairing in this manner to know whether your job will hold or not.

much better to buy a long length of proper fuel hose (available from most good parts stockists, Euro car parts will do it) and trace the fuel lline back to a section that can be cut and joined properly, you may need to insert a metal (copper / aluminium) section to join 2 sections of rubber hose together along with a couple of jubilee clips.

If you can't find a suitable section of rubber hose on your system to cut and join then its game over unless you can find a suitable replacement part.

You can make a permanent repair by using a joiner which consists of a nut and an olive on each end of the broken pipe, which then screws onto the centre joining piece. These are designed for high pressure use.

Sounds like a good idea, similar to joining 2 copper pipes in the house.

You can buy push fit fuel line connectors for nylon fuel pipe.

I have seen these for air systems, they use them all the time on commercial vehicles, wasn't aware they did them for fuel, If so they are by far the easiest way to repair damaged plastic / nylon hoses.