TODO: Assert qL

[johnnyquest]

(Give it a first try as a SOP)

Similar to assertions in programming languages: check if the incoming data (e.g. geometry) matches criteria, send warnings/errors if not.

This would be useful for "documenting" of major network sections (both their start- and endpoints -- what are the expected in/out data criteria).

Criteria ideas (geometry, for now):

• non-empty geometry
  • has at least n components (points, primitives, vertices)
• has the specified attributes
• custom expression (hexpr, hscript, python -- perhaps all other crits could be python script presets)
• ...

UI ideas:

• criteria as multiparm
• entry:
  • text label (single line describing the criterion -- important!)
  • criterion (python code snippet);
  • severity (warning, error, fatal, etc.) -- i.e. behaviour if criterion fails;
  • error msg

[gadfly16]

Good idea. I think this falls very close to the probably yet undocumented idea of the Diff SOP and in less extent to the Unit Test OBJ node. All three are the logical extensions of Houdini as a graphical programming environment. Complex workflows could certainly benefit from these utilities.

[johnnyquest]

These could be saved gallery items based on the Error SOP