feat(hooks): add useNodes and useEdges

src/hooks/useEdges.ts

@@ -0,0 +1,12 @@
+import { useStore } from '../store';
+import { Edge, ReactFlowState } from '../types';
+
+const edgesSelector = (state: ReactFlowState) => state.edges;
+
+function useEdges<EdgeData>(): Edge<EdgeData>[] {
+  const edges = useStore(edgesSelector);
+
+  return edges;
+}
+
+export default useEdges;

src/hooks/useNodes.ts

@@ -0,0 +1,12 @@
+import { useStore } from '../store';
+import { Node, ReactFlowState } from '../types';
+
+const nodesSelector = (state: ReactFlowState) => Array.from(state.nodeInternals.values());
+
+function useNodes<NodeData>(): Node<NodeData>[] {
+  const nodes = useStore(nodesSelector);
+
+  return nodes;
+}
+
+export default useNodes;