Branching III

In addition to running a plug-in once for every instance as in the previous example, it can sometimes be useful to define "classes" of instances that a common set of plug-ins can operate on.

Here, a "class of instances" is known as a family and a plug-in may support one or more families, which is another requirement attribute, like hosts.

import pyblish.api
items = ["john.person", "door.prop"]
class CollectInstances(pyblish.api.ContextPlugin):
order = 0
def process(self, context):
for item in items:
name, suffix = item.split(".")
instance = context.create_instance(name)
instance.data["families"] = [suffix]
class PrintPersons(pyblish.api.InstancePlugin):
order = 1
families = ["person"]
def process(self, instance):
print("Person is: %s" % instance)
class PrintProps(pyblish.api.InstancePlugin):
order = 1
families = ["prop"]
def process(self, instance):
print("The prop is: %s" % instance)
pyblish.api.register_plugin(CollectInstances)
pyblish.api.register_plugin(PrintPersons)
pyblish.api.register_plugin(PrintProps)
import pyblish.util
pyblish.util.publish()
# The person is "john"
# The prop is "door"

If you pay special attention to the final output, you can see that "john" was processed by PrintPersons, whereas "door" got processed by PrintProps.