Custom node sample for #69

tests/examples/customnode/admin.py

@@ -0,0 +1,14 @@
+from django.contrib import admin
+from viewflow.admin import ProcessAdmin
+from . import models, flows
+
+
+@admin.register(models.DynamicSplitProcess)
+class DynamicSplitAdmin(ProcessAdmin):
+    list_display = ['pk', 'created', 'get_status_display', 'participants',
+                    'split_count', 'decisions_list']
+
+    list_display_links = ['pk', 'created']
+
+    def decisions_list(self, obj):
+        return ', '.join(['No', 'Yes'][answer.decision] for answer in obj.decision_set.all())

tests/examples/customnode/flows.py

@@ -0,0 +1,29 @@
+from viewflow import flow
+from viewflow.base import this, Flow
+from viewflow.site import viewsite
+from viewflow.views import StartView
+
+from . import models, views
+from .nodes import DynamicSplit
+
+
+class DynamicSplitFlow(Flow):
+    process_cls = models.DynamicSplitProcess
+
+    start = flow.Start(StartView, fields=['split_count']) \
+        .Permission(auto_create=True) \
+        .Next(this.spit_on_decision)
+
+    spit_on_decision = DynamicSplit(lambda p: p.split_count) \
+        .Next(this.make_decision)
+
+    make_decision = flow.View(views.DecisionView) \
+        .Next(this.join_on_decision)
+
+    join_on_decision = flow.Join() \
+        .Next(this.end)
+
+    end = flow.End()
+
+
+viewsite.register(DynamicSplitFlow)

tests/examples/customnode/models.py

@@ -0,0 +1,13 @@
+from django.db import models
+from django.conf import settings
+from viewflow.models import Process
+
+
+class DynamicSplitProcess(Process):
+    split_count = models.IntegerField(default=0)
+
+
+class Decision(models.Model):
+    process = models.ForeignKey(DynamicSplitProcess)
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, blank=True, null=True)
+    decision = models.BooleanField(default=False)

tests/examples/customnode/nodes.py

@@ -0,0 +1,53 @@
+from viewflow.activation import GateActivation
+from viewflow.flow.base import Gateway, Edge
+from viewflow.token import Token
+
+
+class DynamicSplitActivation(GateActivation):
+    def execute(self):
+        self._split_count = self.flow_task._task_count_callback(self.process)
+
+    def activate_next(self):
+        if self._split_count:
+            token_source = Token.split_token_source(self.task.token, self.task.pk)
+            for _ in range(self._split_count):
+                self.flow_task._next_task.activate(prev_activation=self, token=next(token_source))
+
+
+class DynamicSplit(Gateway):
+    """
+    Activates several outgoing task instances depends on callback value
+
+    Example::
+
+        spit_on_decision = flow.DynamicSplit(lambda p: 4) \\
+            .Next(this.make_decision)
+
+        make_decision = flow.View(MyView) \\
+            .Next(this.join_on_decision)
+
+        join_on_decision = flow.Join() \\
+            .Next(this.end)
+    """
+    task_type = 'SPLIT'
+    activation_cls = DynamicSplitActivation
+
+    def __init__(self, callback):
+        super(DynamicSplit, self).__init__()
+        self._next_task, self._task_count_callback = None, callback
+
+    def _outgoing(self):
+        yield Edge(src=self, dst=self._next_task, edge_class='next')
+
+    def Next(self, node):
+        self._next_task = node
+        return self
+
+
+# TODO: Some boilerplate to remove
+from viewflow.resolve import resolve_children_links
+
+
+@resolve_children_links.register(DynamicSplit)
+def _(flow_node, resolver):
+    flow_node._next_task = resolver.get_implementation(flow_node._next_task)

tests/examples/customnode/views.py

@@ -0,0 +1,18 @@
+from django.views import generic
+from viewflow import flow
+
+from . import models
+
+
+class DecisionView(flow.TaskFormViewMixin, generic.CreateView):
+    model = models.Decision
+    fields = ['decision']
+
+    def activation_done(self, form):
+        self.object = form.save(commit=False)
+
+        self.object.user = self.request.user
+        self.object.process = self.activation.process
+        self.object.save()
+
+        self.activation.done()

tests/settings.py

@@ -26,7 +26,8 @@
     'tests.integration',
     # Examples
     'tests.examples.shipment',
-    'tests.examples.helloworld'
+    'tests.examples.helloworld',
+    'tests.examples.customnode',
 )
 
 MIDDLEWARE_CLASSES = (

tests/templates/viewflow/base_site.html

@@ -28,7 +28,8 @@
 <ul class="nav">
     <li {% if request.path == "/" %}class="active"{% endif %}><a href="/">Home</a></li>
     <li {% if "/helloworld/" in request.path %}class="active"{% endif %}><a href="{% flowurl 'helloworld/HelloWorldFlow' 'viewflow:index' %}">Hello, World</a></li>
-    <li {% if "/shipment" in request.path %}class="active"{% endif %}><a href="{% flowurl 'shipment/ShipmentFlow' 'viewflow:index' %}">Shipment</a></li>
+    <li {% if "/shipment/" in request.path %}class="active"{% endif %}><a href="{% flowurl 'shipment/ShipmentFlow' 'viewflow:index' %}">Shipment</a></li>
+    <li {% if "/dynamicsplit/" in request.path %}class="active"{% endif %}><a href="{% flowurl 'customnode/DynamicSplitFlow' 'viewflow:index' %}">Dynamic Split</a></li>
 </ul>
 {% endblock %}