Add StartViewMixin for custom start view tasks (#132)

Co-authored-by: Johannes Maron <johannes@maron.family>

Author: fvollmer

joeflow/models.py

@@ -19,6 +19,7 @@
 from .conf import settings
 from .typing import HUMAN, MACHINE
 from .utils import NoDashDiGraph
+from .views import StartViewMixin
 
 logger = logging.getLogger(__name__)
 
@@ -139,7 +140,7 @@ def urls(cls):
         urls = []
         for name, node in cls.get_nodes():
             if isinstance(node, View):
-                if isinstance(node, BaseCreateView):
+                if isinstance(node, (BaseCreateView, StartViewMixin)):
                     route = f"{name}/"
                 else:
                     route = f"{name}/<int:pk>/"

joeflow/tasks/human.py

@@ -2,15 +2,15 @@
 
 from django.views import generic
 
-from joeflow.views import TaskViewMixin
+from joeflow.views import StartViewMixin, TaskViewMixin
 
 __all__ = (
     "StartView",
     "UpdateView",
 )
 
 
-class StartView(TaskViewMixin, generic.CreateView):
+class StartView(StartViewMixin, generic.CreateView):
     """
     Start a new workflow by a human with a view.
 

joeflow/views.py

@@ -97,6 +97,25 @@ def create_task(self, workflow, prev_task):
         )
 
 
+class StartViewMixin(TaskViewMixin):
+    """
+    View-mixin to create a start workflow.
+
+    Example:
+        class MyStartWorkflowView(StartViewMixin, View):
+            def post(self, request, *args, **kwargs):
+                try:
+                    data = json.loads(request.body)
+                    workflow_id = self.start_workflow(data)
+                except Exception as e:
+                    return HttpResponseBadRequest("Failed to start workflow")
+
+                return JsonResponse({'message': 'Workflow started successfully.', 'id': workflow_id}, status=201)
+    """
+
+    model = None
+
+
 class WorkflowDetailView(WorkflowTemplateNameViewMixin, generic.DetailView):
     pass
 

tests/fixtures/simpleworkflow.dot

@@ -5,7 +5,9 @@ digraph {
 	"save the princess" [color=black fontcolor=black style="filled, rounded"]
 	"start method" [color=black fontcolor=black style=filled]
 	"start view" [color=black fontcolor=black style="filled, rounded"]
+	"custom start view" [color=black fontcolor=black style="filled, rounded"]
 	"save the princess" -> end [color=black]
 	"start method" -> "save the princess" [color=black]
 	"start view" -> "save the princess" [color=black]
+	"custom start view" -> "save the princess" [color=black]
 }

tests/fixtures/simpleworkflow_instance.dot

@@ -5,7 +5,9 @@ digraph {
 	"save the princess" [color=black fontcolor=black href="/simple/save_the_princess/2/" peripheries=1 style="filled, rounded, bold"]
 	"start method" [color=black fontcolor=black peripheries=1 style=filled]
 	"start view" [color="#888888" fontcolor="#888888" style="filled, rounded"]
+	"custom start view" [color="#888888" fontcolor="#888888" style="filled, rounded"]
 	"save the princess" -> end [color="#888888"]
 	"start method" -> "save the princess" [color=black]
 	"start view" -> "save the princess" [color="#888888"]
+	"custom start view" -> "save the princess" [color="#888888"]
 }

tests/test_models.py

@@ -207,6 +207,7 @@ def test_urls(self):
         assert namespace == "simpleworkflow"
         names = {pattern.name for pattern in patterns}
         assert names == {
+            "custom_start_view",
             "save_the_princess",
             "start_view",
             "override",

tests/testapp/workflows.py

@@ -1,8 +1,10 @@
 from datetime import timedelta
 
 from django.core.mail import send_mail
+from django.views import generic
 
 from joeflow import tasks
+from joeflow.views import StartViewMixin
 
 from . import models
 from .views import UpdateWithPrevUserView
@@ -40,8 +42,13 @@ class Meta:
         proxy = True
 
 
+class CustomStartViewTaskView(StartViewMixin, generic.View):
+    pass
+
+
 class SimpleWorkflow(models.SimpleWorkflowState):
     start_view = tasks.StartView(fields="__all__", path="custom/postfix/")
+    custom_start_view = CustomStartViewTaskView()
     start_method = tasks.Start()
     save_the_princess = tasks.UpdateView(fields="__all__")
 
@@ -50,6 +57,7 @@ def end(self):
 
     edges = (
         (start_view, save_the_princess),
+        (custom_start_view, save_the_princess),
         (start_method, save_the_princess),
         (save_the_princess, end),
     )