Add link between corporation and its parent

stages/admin.py

@@ -70,8 +70,8 @@ class CorporationAdmin(admin.ModelAdmin):
     list_editable = ('short_name',)  # Temporarily?
     search_fields = ('name', 'pcode', 'city')
     ordering = ('name',)
-    fields = (('name', 'short_name', 'sector'), ('typ', 'ext_id'), 'street', ('pcode', 'city'), ('tel', 'email'),
-              'web', 'archived')
+    fields = (('name', 'short_name'), 'parent', ('sector', 'typ', 'ext_id'),
+              'street', ('pcode', 'city'), ('tel', 'email'), 'web', 'archived')
     inlines = [ContactInline]
 
 

stages/migrations/0006_corporation_parent.py

@@ -0,0 +1,19 @@
+# Generated by Django 1.9.1 on 2016-01-18 12:23
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stages', '0005_extended_contact_email'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='corporation',
+            name='parent',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL,
+                to='stages.Corporation', verbose_name='Institution mère'),
+        ),
+    ]

stages/models.py

@@ -121,6 +121,7 @@ class Corporation(models.Model):
     ext_id = models.IntegerField(null=True, blank=True, verbose_name='ID externe')
     name = models.CharField(max_length=100, verbose_name='Nom', unique=True)
     short_name = models.CharField(max_length=40, blank=True, verbose_name='Nom court')
+    parent = models.ForeignKey('self', null=True, blank=True, verbose_name='Institution mère', on_delete=models.SET_NULL)
     sector = models.CharField(max_length=40, blank=True, verbose_name='Secteur')
     typ = models.CharField(max_length=40, blank=True, verbose_name='Type de structure')
     street = models.CharField(max_length=100, blank=True, verbose_name='Rue')