Ensure we load dependencies when updating cache for new models.

Fixes coleifer/sqlite-web#42

playhouse/dataset.py

@@ -84,6 +84,8 @@ def update_cache(self, table=None):
  dependencies.extend([
  related._meta.table_name for _, related, _ in
  model_class._meta.model_graph()])
+ else:
+ dependencies.extend(self.get_table_dependencies(table))
  else:
  dependencies = None # Update all tables.
  updated = self._introspector.generate_models(
@@ -92,6 +94,19 @@ def update_cache(self, table=None):
  literal_column_names=True)
  self._models.update(updated)
 
+ def get_table_dependencies(self, table):
+ stack = [table]
+ accum = []
+ seen = set()
+ while stack:
+ table = stack.pop()
+ for fk_meta in self._database.get_foreign_keys(table):
+ dest = fk_meta.dest_table
+ if dest not in seen:
+ stack.append(dest)
+ accum.append(dest)
+ return accum
+
  def __enter__(self):
  self.connect()
  return self