This knitted strap will let the door hang open, but won't let it be pushed open. It will also allow you to adjust how far the door can go.

Supplies

Yarn
Knitting needles (any size)
Button
Needle and thread

Step 1:

Tie a small loop on the end of your yarn. Cast on six stitches leaving a four inch tail of extra yarn* with a loop on the end.

*You can adjust the length here for how wide you want your door to go, just keep in mind that it will get longer with the first row.

Step 2:

Knit for about seven inches then bind off. Tie the thread to a strand of yarn at the end without the tail. Sew on the button.

Step 3: How to Set It

This should work on most indoor doors. Look inside the notch in the doorframe, and see if there's a little metal piece inside you can hook the loop around, if so it will work. You will have to use your fingers to get it in. The button side should loop around the door handle one the side the door opens on, the button will go through knitted part.