Basic view

src/registrar/config/urls.py

@@ -182,6 +182,11 @@ urlpatterns = [
         views.DomainOrgNameAddressView.as_view(),
         name="domain-org-name-address",
     ),
+    path(
+        "domain/<int:pk>/suborganization",
+        views.DomainSubOrganizationView.as_view(),
+        name="domain-suborganization",
+    ),
     path(
         "domain/<int:pk>/senior-official",
         views.DomainSeniorOfficialView.as_view(),

src/registrar/forms/domain.py

@@ -16,7 +16,7 @@ from registrar.utility.errors import (
     SecurityEmailErrorCodes,
 )
 
-from ..models import Contact, DomainInformation, Domain, User
+from ..models import Contact, DomainInformation, Domain, User, Suborganization
 from .common import (
     ALGORITHM_CHOICES,
     DIGEST_TYPE_CHOICES,
@@ -508,6 +508,41 @@ class DomainOrgNameAddressForm(forms.ModelForm):
         return old_value == new_value
 
 
+class DomainSuborganizationForm(forms.ModelForm):
+    """Form for updating the suborganization"""
+
+    class Meta:
+        model = DomainInformation
+        fields = [
+            "sub_organization",
+        ]
+        error_messages = {
+            "sub_organization": {"required": "Select a suborganization."},
+        }
+        widgets = {
+            "sub_organization": forms.Select(
+                attrs={
+                    "required": False,
+                },
+            ),
+        }
+
+    # the database fields have blank=True so ModelForm doesn't create
+    # required fields by default. Use this list in __init__ to mark each
+    # of these fields as required
+    required = ["sub_organization"]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields["sub_organization"].required = False
+        if self.instance and self.instance.portfolio:
+            self.fields['sub_organization'].queryset = Suborganization.objects.filter(
+                portfolio=self.instance.portfolio
+            )
+        else:
+            self.fields['sub_organization'].queryset = Suborganization.objects.none()
+
+
 class DomainDnssecForm(forms.Form):
     """Form for enabling and disabling dnssec"""
 

src/registrar/templates/domain_sidebar.html

@@ -54,15 +54,12 @@
         </ul>
         {% endif %}
       </li>
-
-      <li class="usa-sidenav__item">
-        {% url 'domain-org-name-address' pk=domain.id as url %}
-        <a href="{{ url }}"
-          {% if request.path == url %}class="usa-current"{% endif %}
-        >
-            Organization name and mailing address
-        </a>
-      </li>      
+      
+      {% if is_org_user %}
+        {% include "includes/domain_sidenav_item.html" with url_name="domain-suborganization" item_text="Suborganization"%}
+      {% else %}
+        {% include "includes/domain_sidenav_item.html" with url_name="domain-org-name-address" item_text="Organization name and mailing address"%}
+      {% endif %}    
 
       <li class="usa-sidenav__item">
         {% url 'domain-senior-official' pk=domain.id as url %}

src/registrar/templates/domain_suborganization.html

@@ -0,0 +1,25 @@
+{% extends "domain_base.html" %}
+{% load static field_helpers%}
+
+{% block title %}Suborganization{% endblock %}
+
+{% block domain_content %}
+    {# this is right after the messages block in the parent template #}
+    {% include "includes/form_errors.html" with form=form %}
+
+    <h1>Organization name and mailing address </h1>
+
+    <p>
+        The name of your suborganization will be publicly listed as the domain registrant. 
+        This list of suborganizations has been populated the .gov program. 
+        If you believe there is an error please contact <a href="mailto:help@get.gov" class="usa-link">help@get.gov</a>.
+    </p>
+
+    {% include "includes/required_fields.html" %}
+    <form class="usa-form usa-form--large" method="post" novalidate id="form-container">
+        {% csrf_token %}
+        {% input_with_errors form.sub_organization %}
+        <button type="submit" class="usa-button">Save</button>
+    </form>
+
+{% endblock %}

src/registrar/templates/includes/domain_sidenav_item.html

@@ -0,0 +1,8 @@
+<li class="usa-sidenav__item">
+    {% url url_name pk=domain.id as url %}
+    <a href="{{ url }}"
+      {% if request.path == url %}class="usa-current"{% endif %}
+    >
+        {{ item_text }}
+    </a>
+</li> 

src/registrar/views/__init__.py

@@ -3,6 +3,7 @@ from .domain import (
     DomainView,
     DomainSeniorOfficialView,
     DomainOrgNameAddressView,
+    DomainSubOrganizationView,
     DomainDNSView,
     DomainNameserversView,
     DomainDNSSECView,

src/registrar/views/domain.py

@@ -16,6 +16,7 @@ from django.urls import reverse
 from django.views.generic.edit import FormMixin
 from django.conf import settings
 
+from registrar.forms.domain import DomainSuborganizationForm
 from registrar.models import (
     Domain,
     DomainRequest,
@@ -221,6 +222,34 @@ class DomainOrgNameAddressView(DomainFormBaseView):
         return super().form_valid(form)
 
 
+class DomainSubOrganizationView(DomainFormBaseView):
+    """Suborganization view"""
+
+    model = Domain
+    template_name = "domain_suborganization.html"
+    context_object_name = "domain"
+    form_class = DomainSuborganizationForm
+
+    def get_form_kwargs(self, *args, **kwargs):
+        """Add domain_info.organization_name instance to make a bound form."""
+        form_kwargs = super().get_form_kwargs(*args, **kwargs)
+        form_kwargs["instance"] = self.object.domain_info
+        return form_kwargs
+
+    def get_success_url(self):
+        """Redirect to the overview page for the domain."""
+        return reverse("domain-suborganization", kwargs={"pk": self.object.pk})
+
+    def form_valid(self, form):
+        """The form is valid, save the organization name and mailing address."""
+        form.save()
+
+        messages.success(self.request, "The suborganization name for this domain has been updated.")
+
+        # superclass has the redirect
+        return super().form_valid(form)
+
+
 class DomainSeniorOfficialView(DomainFormBaseView):
     """Domain senior official editing view."""