Towerdefense building check

Beginner Questions
1

I got a Towerdefense game going with a gridgraph. How can i check if there is a valid path from the start to the end?
When I calculate a path it doesnt throw an error out,but the path stops in the unwalkable area.
How can I do it so that I can close the needed nodes for building ?

2

Hi

You should take a look at this API: http://arongranberg.com/astar/docs_dev/class_pathfinding_1_1_graph_update_utilities.php#af1d9912f395e3a1b5ef4f21d1f19da74

3

Hi!

Thanks for the fast support! Really amazing!
I already took a look at this and now I got stuck in getting my wanted graphnode.
How I can get my wanted graphnode out of my gridgraph?

Edit: I already figured it out! Thanks for this great pathfinding solution!