How to bind a object on a vertex of curve? (This curve has shape keys animation.)

I add a curve shape keys, it can become a line or a circle.
And i want to bind a object at a point or this curve, let it seem like as sticke on an rope,
Whatever curve shape keys change, the object still sticke on curve.
How to do it?
Thanks all reply.

you can use vertex parent .select the child then the parent in object mode,then go to edit mode with both selected ,select the vertex you want to bind it to ,hit ctrl +p.

Edit:sorry vertex parent seems to not work with curves which have shapekeys

Thank you. I can add curve modify for mesh, so it can bind object and distort with curve. But, there are two problems: (1) The object always face to same direction when curve distort. (2) I hope this function can be use in BGE… Maybe…I have to use follow-path ?

yes thats the best way physics