Add support for generating diagrams from workflows.

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

mayan/apps/document_states/apps.py

@@ -36,8 +36,9 @@ from .links import (
     link_setup_workflow_transition_delete, link_setup_workflow_transition_edit,
     link_tool_launch_all_workflows, link_workflow_instance_detail,
     link_workflow_instance_transition, link_workflow_document_list,
-    link_workflow_list, link_workflow_state_document_list,
-    link_workflow_state_list, link_workflow_instance_transition_events
+    link_workflow_list, link_workflow_preview,
+    link_workflow_state_document_list, link_workflow_state_list,
+    link_workflow_instance_transition_events
 )
 from .permissions import permission_workflow_transition
 from .queues import *  # NOQA
@@ -220,7 +221,8 @@ class DocumentStatesApp(MayanAppConfig):
             links=(
                 link_setup_workflow_states, link_setup_workflow_transitions,
                 link_setup_workflow_document_types, link_setup_workflow_edit,
-                link_acl_list, link_setup_workflow_delete
+                link_acl_list, link_workflow_preview,
+                link_setup_workflow_delete
             ), sources=(Workflow,)
         )
         menu_object.bind_links(

mayan/apps/document_states/forms.py

@@ -12,6 +12,7 @@ from .classes import WorkflowAction
 from .models import (
     Workflow, WorkflowState, WorkflowStateAction, WorkflowTransition
 )
+from .widgets import WorkflowImageWidget
 
 
 class WorkflowActionSelectionForm(forms.Form):
@@ -157,3 +158,12 @@ class WorkflowInstanceTransitionForm(forms.Form):
     comment = forms.CharField(
         label=_('Comment'), required=False, widget=forms.widgets.Textarea()
     )
+
+
+class WorkflowPreviewForm(forms.Form):
+    preview = forms.CharField(widget=WorkflowImageWidget())
+
+    def __init__(self, *args, **kwargs):
+        instance = kwargs.pop('instance', None)
+        super(WorkflowPreviewForm, self).__init__(*args, **kwargs)
+        self.fields['preview'].initial = instance

mayan/apps/document_states/links.py

@@ -37,6 +37,25 @@ link_setup_workflow_list = Link(
     permissions=(permission_workflow_view,), icon='fa fa-sitemap',
     text=_('Workflows'), view='document_states:setup_workflow_list'
 )
+link_setup_workflow_state_action_delete = Link(
+    args='resolved_object.pk', permissions=(permission_workflow_edit,),
+    tags='dangerous', text=_('Delete'),
+    view='document_states:setup_workflow_state_action_delete',
+)
+link_setup_workflow_state_action_edit = Link(
+    args='resolved_object.pk', permissions=(permission_workflow_edit,),
+    text=_('Edit'), view='document_states:setup_workflow_state_action_edit',
+)
+link_setup_workflow_state_action_list = Link(
+    args='resolved_object.pk', permissions=(permission_workflow_edit,),
+    text=_('Actions'),
+    view='document_states:setup_workflow_state_action_list',
+)
+link_setup_workflow_state_action_selection = Link(
+    args='resolved_object.pk', permissions=(permission_workflow_edit,),
+    text=_('Create action'),
+    view='document_states:setup_workflow_state_action_selection',
+)
 link_setup_workflow_state_create = Link(
     permissions=(permission_workflow_edit,), text=_('Create state'),
     view='document_states:setup_workflow_state_create', args='object.pk'
@@ -110,28 +129,7 @@ link_workflow_instance_transition_events = Link(
     text=_('Transition events'),
     view='document_states:setup_workflow_instance_transition_events'
 )
-
-###
-
-link_setup_workflow_state_action_list = Link(
-    args='resolved_object.pk', permissions=(permission_workflow_edit,),
-    text=_('Actions'),
-    view='document_states:setup_workflow_state_action_list',
-)
-
-link_setup_workflow_state_action_selection = Link(
-    args='resolved_object.pk', permissions=(permission_workflow_edit,),
-    text=_('Create action'),
-    view='document_states:setup_workflow_state_action_selection',
-)
-
-
-link_setup_workflow_state_action_delete = Link(
-    args='resolved_object.pk', permissions=(permission_workflow_edit,),
-    tags='dangerous', text=_('Delete'),
-    view='document_states:setup_workflow_state_action_delete',
-)
-link_setup_workflow_state_action_edit = Link(
-    args='resolved_object.pk', permissions=(permission_workflow_edit,),
-    text=_('Edit'), view='document_states:setup_workflow_state_action_edit',
+link_workflow_preview = Link(
+    args='resolved_object.pk', permissions=(permission_workflow_view,),
+    text=_('Preview'), view='document_states:workflow_preview'
 )

mayan/apps/document_states/models.py

@@ -3,6 +3,8 @@ from __future__ import absolute_import, unicode_literals
 import json
 import logging
 
+from graphviz import Digraph
+
 from django.conf import settings
 from django.core.exceptions import PermissionDenied, ValidationError
 from django.db import IntegrityError, models
@@ -78,6 +80,48 @@ class Workflow(models.Model):
                 'Workflow %s launched for document %s', self, document
             )
 
+    def render(self):
+        diagram = Digraph(
+            name='finite_state_machine', graph_attr={
+                'rankdir': 'LR', 'size': '8,5'
+            }, format='png'
+        )
+
+        state_cache = {}
+        transition_cache = []
+
+        for state in self.states.all():
+            state_cache['s{}'.format(state.pk)] = {
+                'name': 's{}'.format(state.pk),
+                'label': state.label,
+                'initial': state.initial,
+                'connections': {'origin': 0, 'destination': 0}
+            }
+
+        for transition in self.transitions.all():
+            transition_cache.append(
+                {
+                    'tail_name': 's{}'.format(transition.origin_state.pk),
+                    'head_name': 's{}'.format(transition.destination_state.pk),
+                    'label': transition.label
+                }
+            )
+            state_cache['s{}'.format(transition.origin_state.pk)]['connections']['origin'] = state_cache['s{}'.format(transition.origin_state.pk)]['connections']['origin'] + 1
+            state_cache['s{}'.format(transition.destination_state.pk)]['connections']['destination'] += 1
+
+        for key, value in state_cache.items():
+            kwargs = {
+                'name': value['name'],
+                'label': value['label'],
+                'shape': 'doublecircle' if value['connections']['origin'] == 0 or value['connections']['destination'] == 0 or value['initial'] else 'circle',
+            }
+            diagram.node(**kwargs)
+
+        for transition in transition_cache:
+            diagram.edge(**transition)
+
+        return diagram.pipe()
+
     class Meta:
         ordering = ('label',)
         verbose_name = _('Workflow')

mayan/apps/document_states/urls.py

@@ -22,8 +22,8 @@ from .views import (
     SetupWorkflowTransitionEditView,
     SetupWorkflowTransitionTriggerEventListView, ToolLaunchAllWorkflows,
     WorkflowDocumentListView, WorkflowInstanceDetailView,
-    WorkflowInstanceTransitionView, WorkflowListView,
-    WorkflowStateDocumentListView, WorkflowStateListView,
+    WorkflowImageView, WorkflowInstanceTransitionView, WorkflowListView,
+    WorkflowPreviewView, WorkflowStateDocumentListView, WorkflowStateListView,
 )
 
 urlpatterns = [
@@ -165,6 +165,16 @@ urlpatterns = [
         WorkflowStateListView.as_view(),
         name='workflow_state_list'
     ),
+    url(
+        r'^(?P<pk>\d+)/image/$',
+        WorkflowImageView.as_view(),
+        name='workflow_image'
+    ),
+    url(
+        r'^(?P<pk>\d+)/preview/$',
+        WorkflowPreviewView.as_view(),
+        name='workflow_preview'
+    ),
     url(
         r'^state/(?P<pk>\d+)/documents/$',
         WorkflowStateDocumentListView.as_view(),

mayan/apps/document_states/views.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
 from django.contrib import messages
+from django.core.files.base import ContentFile
 from django.db.utils import IntegrityError
 from django.http import Http404, HttpResponseRedirect
 from django.shortcuts import get_object_or_404
@@ -10,9 +11,9 @@ from django.utils.translation import ugettext_lazy as _
 from acls.models import AccessControlList
 from common.views import (
     AssignRemoveView, ConfirmView, FormView, SingleObjectCreateView,
-    SingleObjectDeleteView, SingleObjectDynamicFormCreateView,
-    SingleObjectDynamicFormEditView, SingleObjectEditView,
-    SingleObjectListView
+    SingleObjectDeleteView, SingleObjectDetailView,
+    SingleObjectDynamicFormCreateView, SingleObjectDynamicFormEditView,
+    SingleObjectDownloadView, SingleObjectEditView, SingleObjectListView
 )
 from documents.models import Document
 from documents.views import DocumentListView
@@ -22,8 +23,8 @@ from events.models import EventType
 from .classes import WorkflowAction
 from .forms import (
     WorkflowActionSelectionForm, WorkflowForm, WorkflowInstanceTransitionForm,
-    WorkflowStateActionDynamicForm, WorkflowStateForm, WorkflowTransitionForm,
-    WorkflowTransitionTriggerEventRelationshipFormSet
+    WorkflowPreviewForm, WorkflowStateActionDynamicForm, WorkflowStateForm,
+    WorkflowTransitionForm, WorkflowTransitionTriggerEventRelationshipFormSet
 )
 from .models import (
     Workflow, WorkflowInstance, WorkflowState, WorkflowStateAction,
@@ -733,3 +734,28 @@ class ToolLaunchAllWorkflows(ConfirmView):
         messages.success(
             self.request, _('Workflow launch queued successfully.')
         )
+
+
+class WorkflowImageView(SingleObjectDownloadView):
+    attachment = False
+    model = Workflow
+    object_permission = permission_workflow_view
+
+    def get_file(self):
+        workflow = self.get_object()
+        return ContentFile(workflow.render(), name=workflow.label)
+
+    def get_mimetype(self):
+        return 'image'
+
+
+class WorkflowPreviewView(SingleObjectDetailView):
+    form_class = WorkflowPreviewForm
+    model = Workflow
+    object_permission = permission_workflow_view
+
+    def get_extra_context(self):
+        return {
+            'hide_labels': True,
+            'title': _('Preview of: %s') % self.get_object()
+        }

mayan/apps/document_states/widgets.py

@@ -1,6 +1,8 @@
 from __future__ import unicode_literals
 
-from django.utils.html import format_html_join
+from django import forms
+from django.urls import reverse
+from django.utils.html import format_html_join, mark_safe
 
 
 def widget_transition_events(transition):
@@ -11,3 +13,23 @@ def widget_transition_events(transition):
             ) for transition_trigger in transition.trigger_events.all()
         )
     )
+
+
+def widget_workflow_diagram(workflow):
+    return mark_safe(
+        '<img class="img-responsive" src="{}">'.format(
+            reverse('document_states:workflow_image', args=(workflow.pk,))
+        )
+    )
+
+
+class WorkflowImageWidget(forms.widgets.Widget):
+    def render(self, name, value, attrs=None):
+        final_attrs = self.build_attrs(attrs)
+
+        if value:
+            output = []
+            output.append(widget_workflow_diagram(value))
+            return mark_safe(''.join(output))
+        else:
+            return ''