wip: Checker class

proposals/utils/stepper.py

@@ -3,6 +3,8 @@
 from django.template import loader, Template
 from django.core.exceptions import ImproperlyConfigured
 
+from proposals.views.proposal_views import ProposalUpdate
+
 def flatten(lst):
     if lst == []:
         return lst
@@ -27,11 +29,13 @@ def render(self, context={}):
 class Stepper(renderable):
 
     template_name = "base/stepper.html"
+    starting_checkers = []
 
     def __init__(self, proposal, current=None):
 
         self.proposal = proposal
         self.current = current
+        self.check_all(self.starting_checkers)
 
     def get_context_data(self):
         return {"stepper": self}
@@ -53,32 +57,95 @@ def collect_items(self):
             some_pages.append(
                 Page(self.proposal)
             )
+        first_page = FirstPage()
+        some_pages.append(first_page)
         return some_pages
 
+    def check_all(self, next_checkers):
+        # No more checkers means we are done
+        if next_checkers == []:
+            return True
+        # Instantiate next checker
+        # and give it access to the stepper
+        current = next_checkers.pop(0)(self)
+        # Run the check method
+        # and gather new checkers from its output
+        new_checkers = current.check()
+        # Combine the lists, new checkers come first
+        next_checkers = new_checkers + next_checkers
+        # Recurse until next_checkers is empty
+        return self.check_all(next_checkers)
+
+class BaseChecker:
+
+    def __init__(self, stepper):
+        self.stepper = stepper
+
+    def __call__(self, *args, **kwargs):
+        """
+        This class may be called to initialize it when it is
+        already initialized. For now, we don't do anything with this
+        and pretend we just got initialized.
+        """
+        return self
+
+    def check(self):
+        """
+        This method gets called to process an item in the proposal creation
+        process. It finall returns a list of checkers with which to continue
+        the checking process. This list can be empty.
+        """
+        return []
+
 
-class StepperContextMixin:
+class StepperItem:
     """
-    Includes a stepper object in the view's context
+    Represents an item in the stepper
     """
 
-    def get_context_data(self, *args, **kwargs):
-        context = super().get_context_data(*args, **kwargs)
-        # Try to determine proposal
-        if hasattr(self, "proposal"):
-            proposal = self.proposal
-        else:
-            proposal = Proposal.objects.get(pk=self.kwargs.get("pk"))
-        # Initialize and insert stepper object
-        context["stepper"] = Stepper(proposal)
-        return context
+    stepper_title = "Stepper item"
+    stepper_children = []
+    available = True
+
+    @property
+    def stepper_url(self):
+        return "#"
+
+    def is_current(self, request):
+        """
+        Returns True if this item represents the page the user
+        is currently on.
+        """
+        return False
+
+class FormPage(StepperItem):
+
+    def instantiate(self):
+        pass
+
+class ViewPage(StepperItem):
+
+    view_class = None
+
+    def is_current(self, request):
+        breakpoint()
+        return True
 
+    def css_classes(self):
+        classes = set()
+        if self.is_current():
+            classess.add("current")
 
-class Page:
+
+class FirstPage(ViewPage):
+
+    view_class = ProposalUpdate
+
+
+class Page(StepperItem):
     """Represents both a visitable page in the proposal form,
     and an entry in the stepper."""
 
-    stepper_title = "Stepper item"
-
     def __init__(self, proposal, current=None):
         """Initialize the page with the proposal object"""
         self.proposal = proposal