Django filter many-to-many with contains

Question

I am trying to filter a bunch of objects through a many-to-many relation. Because the trigger_roles field may contain multiple entries I tried the contains filter. But as that is designed to be used with strings I'm pretty much helpless how i should filter this relation (you can ignore the values_list() atm.).

This function is attached to the user profile:

def getVisiblePackages(self):
    visiblePackages = {}   
    for product in self.products.all():
        moduleDict = {}
        for module in product.module_set.all():
            pkgList = []
            involvedStatus = module.workflow_set.filter(trigger_roles__contains=self.role.id,allowed=True).values_list('current_state', flat=True)

My workflow model looks like this (simplified):

class Workflow(models.Model):
    module = models.ForeignKey(Module)
    current_state = models.ForeignKey(Status)
    next_state = models.ForeignKey(Status)
    allowed = models.BooleanField(default=False)
    involved_roles = models.ManyToManyField(Role, blank=True, null=True)
    trigger_roles = models.ManyToManyField(Role, blank=True, null=True)

Though the solution might be quiet simple, my brain won't tell me.

Thanks for your help.

Answer 1

Have you tried something like this:

module.workflow_set.filter(trigger_roles__in=[self.role], allowed=True)

or just if self.role.id is not a list of pks:

module.workflow_set.filter(trigger_roles__id__exact=self.role.id, allowed=True)