Initial commit to support workflow actions.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_states/models.py

@@ -1,5 +1,6 @@
 from __future__ import absolute_import, unicode_literals
 
+import json
 import logging
 
 from django.conf import settings
@@ -8,6 +9,7 @@ from django.db import IntegrityError, models
 from django.db.models import F, Max, Q
 from django.urls import reverse
 from django.utils.encoding import force_text, python_2_unicode_compatible
+from django.utils.module_loading import import_string
 from django.utils.translation import ugettext_lazy as _
 
 from acls.models import AccessControlList
@@ -16,6 +18,10 @@ from documents.models import Document, DocumentType
 from events.models import EventType
 from permissions import Permission
 
+from .literals import (
+    WORKFLOW_ACTION_WHEN_CHOICES, WORKFLOW_ACTION_ON_ENTRY,
+    WORKFLOW_ACTION_ON_EXIT
+)
 from .managers import WorkflowManager
 from .permissions import permission_workflow_transition
 
@@ -123,6 +129,14 @@ class WorkflowState(models.Model):
             self.workflow.states.all().update(initial=False)
         return super(WorkflowState, self).save(*args, **kwargs)
 
+    @property
+    def entry_actions(self):
+        return self.actions.filter(when=WORKFLOW_ACTION_ON_ENTRY)
+
+    @property
+    def exit_actions(self):
+        return self.actions.filter(when=WORKFLOW_ACTION_ON_EXIT)
+
     def get_documents(self):
         latest_entries = WorkflowInstanceLogEntry.objects.annotate(
             max_datetime=Max(
@@ -149,6 +163,58 @@ class WorkflowState(models.Model):
         ).distinct()
 
 
+@python_2_unicode_compatible
+class WorkflowStateAction(models.Model):
+    state = models.ForeignKey(
+        WorkflowState, on_delete=models.CASCADE,
+        related_name='actions', verbose_name=_('Workflow state')
+    )
+    label = models.CharField(max_length=255, verbose_name=_('Label'))
+    enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
+    when = models.PositiveIntegerField(
+        choices=WORKFLOW_ACTION_WHEN_CHOICES,
+        default=WORKFLOW_ACTION_ON_ENTRY, help_text=_(
+            'At which moment of the state this action will execute'
+        ), verbose_name=_('When')
+    )
+    action_path = models.CharField(
+        max_length=128, help_text=_(
+            'The dotted Python path to the workflow action class to execute.'
+        ), verbose_name=_('Entry action path')
+    )
+    action_data = models.TextField(
+        blank=True, verbose_name=_('Entry action data')
+    )
+
+    def __str__(self):
+        return self.label
+
+    class Meta:
+        ordering = ('label',)
+        unique_together = ('state', 'label')
+        verbose_name = _('Workflow state action')
+        verbose_name_plural = _('Workflow state actions')
+
+    def dumps(self, data):
+        self.action_data = json.dumps(data)
+        self.save()
+
+    def execute(self, context):
+        self.get_class_instance().execute(context=context)
+
+    def get_class(self):
+        return import_string(self.action_path)
+
+    def get_class_label(self):
+        return self.get_class().label
+
+    def get_class_instance(self):
+        return self.get_class()(**self.loads())
+
+    def loads(self):
+        return json.loads(self.action_data)
+
+
 @python_2_unicode_compatible
 class WorkflowTransition(models.Model):
     workflow = models.ForeignKey(
@@ -156,7 +222,6 @@ class WorkflowTransition(models.Model):
         verbose_name=_('Workflow')
     )
     label = models.CharField(max_length=255, verbose_name=_('Label'))
-
     origin_state = models.ForeignKey(
         WorkflowState, on_delete=models.CASCADE,
         related_name='origin_transitions', verbose_name=_('Origin state')
@@ -341,6 +406,17 @@ class WorkflowInstanceLogEntry(models.Model):
         if self.transition not in self.workflow_instance.get_transition_choices(_user=self.user):
             raise ValidationError(_('Not a valid transition choice.'))
 
+    def save(self, *args, **kwargs):
+        result = super(WorkflowInstanceLogEntry, self).save(*args, **kwargs)
+
+        for action in self.transition.origin_state.exit_actions.all():
+            action.execute(context={'entry_log': self})
+
+        for action in self.transition.destination_state.entry_actions.all():
+            action.execute(context={'entry_log': self})
+
+        return result
+
 
 class WorkflowRuntimeProxy(Workflow):
     class Meta: