Tip: Always RelateIfNeeded when using HttpShell

The InfoGrid HttpShell is something rather amazing when creating web applications. With just a little bit of HTML markup, we can modify the graph of nodes and edges in the GraphDB any way we want, all without writing any handler code for it.

For edges, it understands the keywords:

  • relate
  • relateIfNeeded
  • unrelate
  • unrelateIfNeeded

Relate will fail if the two nodes in question are related already. And in practice, that turns out to be more common than one would assume; only blessing of the edge with the appropriate RoleType is often needed.

So here’s the tip of the day: unless there are good reasons not to, use “relateIfNeeded” and “unrelateIfNeeded” for your application code.