implemented add client hold and remove client hold; extended change permission on domain admin to staff; conditionally display buttons based on state; added states to domain to match state diagram

src/registrar/admin.py

@@ -164,7 +164,6 @@ class MyHostAdmin(AuditedAdmin):
 
     inlines = [HostIPInline]
 
-
 class DomainAdmin(ListHeaderAdmin):
 
     """Custom domain admin class to add extra buttons."""
@@ -175,10 +174,12 @@ class DomainAdmin(ListHeaderAdmin):
     readonly_fields = ["state"]
 
     def response_change(self, request, obj):
-        ACTION_BUTTON = "_place_client_hold"
-        if ACTION_BUTTON in request.POST:
+        PLACE_HOLD = "_place_client_hold"
+        REMOVE_HOLD = "_remove_client_hold"
+        if PLACE_HOLD in request.POST:
             try:
                 obj.place_client_hold()
+                obj.save()
             except Exception as err:
                 self.message_user(request, err, messages.ERROR)
             else:
@@ -191,9 +192,31 @@ class DomainAdmin(ListHeaderAdmin):
                     % obj.name,
                 )
             return HttpResponseRedirect(".")
-
+        elif REMOVE_HOLD in request.POST:
+            try:
+                obj.remove_client_hold()
+                obj.save()
+            except Exception as err:
+                self.message_user(request, err, messages.ERROR)
+            else:
+                self.message_user(
+                    request,
+                    (
+                        "%s is ready. This domain is accessible on the public "
+                        "internet."
+                    )
+                    % obj.name,
+                )
+            return HttpResponseRedirect(".")
         return super().response_change(request, obj)
 
+    def has_change_permission(self, request, obj=None):
+        # Fixes a bug wherein users which are only is_staff
+        # can access 'change' when GET,
+        # but cannot access this page when it is a request of type POST.
+        if request.user.is_staff:
+            return True
+        return super().has_change_permission(request, obj)
 
 class ContactAdmin(ListHeaderAdmin):
     """Custom contact admin class to add search."""

src/registrar/models/domain.py

@@ -2,7 +2,7 @@ import logging
 
 from datetime import date
 from string import digits
-from django_fsm import FSMField  # type: ignore
+from django_fsm import FSMField, transition  # type: ignore
 
 from django.db import models
 
@@ -114,6 +114,12 @@ class Domain(TimeStampedModel, DomainHelper):
         # the state is indeterminate
         UNKNOWN = "unknown"
 
+        # the ready state for a domain object
+        READY = "ready"
+
+        # when a domain is on hold
+        ONHOLD="onhold"
+
     class Cache(property):
         """
         Python descriptor to turn class methods into properties.
@@ -311,13 +317,21 @@ class Domain(TimeStampedModel, DomainHelper):
         """Time to renew. Not implemented."""
         raise NotImplementedError()
 
+    @transition(
+        field="state", source=[State.READY], target=State.ONHOLD
+    )
     def place_client_hold(self):
         """This domain should not be active."""
-        raise NotImplementedError("This is not implemented yet.")
+        # This method is changing the state of the domain in registrar
+        # TODO: implement EPP call
 
+    @transition(
+        field="state", source=[State.ONHOLD], target=State.READY
+    )
     def remove_client_hold(self):
         """This domain is okay to be active."""
-        raise NotImplementedError()
+        # This method is changing the state of the domain in registrar
+        # TODO: implement EPP call
 
     def __str__(self) -> str:
         return self.name

src/registrar/templates/django/admin/domain_change_form.html

@@ -2,7 +2,11 @@
 
 {% block field_sets %}
     <div class="submit-row">
-        <input type="submit" value="Place hold" name="_place_client_hold">
+        {% if original.state == original.State.READY %}
+          <input type="submit" value="Place hold" name="_place_client_hold">
+        {% elif original.state == original.State.ONHOLD %}
+          <input type="submit" value="Remove hold" name="_remove_client_hold">
+        {% endif %}
     </div>
     {{ block.super }}
 {% endblock %}