Abstract properties of Filter

[mottosso]

It just occured to me that the mandatory properties of Filter et. al. should really be abstract properties. E.g.

class Filter(object):
    @abc.abstractproperty
    def families(self):
        pass

So that whomever implements a plugin, will also have to implement the properties. E.g.

class MyFilter(Filter):
    @property
    def families(self):
        return ['maya']

At the moment, you could implement a plugin, but forget about these properties which would make your plugin not work.

edited: Typo

[tokejepsen]

So that would be for families and hosts?

[mottosso]

So far, yes. And any other mandatory properties we'll end up with.

[mottosso]

Reopening this due to @properties not being accessible in classes that hasn't been instantiated yet, resulting in messier code.

# E.g.
for PluginClass in publish.plugin.discover():
    plugin = PluginClass(instance)
    assert plugin.hosts == ['maya']

# As opposed to:
for plugin in publish.plugin.discover():
    assert plugin.hosts == ['maya']

And in cases where the plugin takes different arguments, such as the Selector taking a Context and the Validator taking an Instance, further checks has to be made prior to getting hosts and families. It'd be more efficient if we could check compatibility before doing any instantiation, as was the case prior to this adjustment.

Thoughts?

[mottosso]

This has been restored to non-properties due to the above explanation.