Tweaked forms for prepopulated read-only slot fields

roms/admin.py

@@ -3,14 +3,22 @@ from django.contrib import admin
 from taggit_helpers.admin import TaggitListFilter, TaggitTabularInline
 
 from roms.models import Rom, RomFile
-
+from roms.forms import RomFileForm, RomFileInlineFormSet
 from gulashromstore.settings import SLOT_COUNT
 
+
 class RomFileInline(admin.TabularInline):
     model = RomFile
+    form = RomFileForm
+    formset = RomFileInlineFormSet
+
+    fields = ('slot', 'binary')
+
+    can_delete = False
     max_num = SLOT_COUNT
     min_num = SLOT_COUNT
 
+
 class RomAdmin(admin.ModelAdmin):
     list_display = ('name', 'approved', 'tag_list')
     list_filter = [TaggitListFilter]

roms/forms.py

@@ -0,0 +1,42 @@
+from django.forms import Field, Widget, ModelForm
+from django.forms.models import BaseInlineFormSet
+
+from roms.models import RomFile
+
+class ReadOnlyWidget(Widget):
+    def render(self, name, value, attrs):
+        final_attrs = self.build_attrs(attrs, name=name)
+        if hasattr(self, 'initial'):
+            value = self.initial
+        return "%s" % (value or '')
+
+    def _has_changed(self, initial, data):
+        return False
+
+
+class ReadOnlyField(Field):
+    widget = ReadOnlyWidget
+    def __init__(self, widget=None, label=None, initial=None, help_text=None):
+        super(ReadOnlyField, self).__init__(self, label=label, initial=initial,
+            help_text=help_text, widget=widget)
+
+    def clean(self, value, initial):
+        self.widget.initial = initial
+        return initial
+
+
+class RomFileForm(ModelForm):
+    slot = ReadOnlyField()
+    class Meta:
+        model = RomFile
+        fields = ['binary']
+
+
+class RomFileInlineFormSet(BaseInlineFormSet):
+
+    def __init__(self, *args, **kwargs):
+        super(RomFileInlineFormSet, self).__init__(*args, **kwargs)
+        # Check that the data doesn't already exist
+        if not kwargs['instance'].romfile_set.all():
+            self.initial = [{'slot' : i} for i in range(1, SLOT_COUNT+1)]
+            self.extra = SLOT_COUNT

roms/models.py

@@ -38,6 +38,9 @@ class Rom(models.Model):
 
         return json
 
+    def __str__(self):
+        return "Rom %s" % self.name
+
 
 
 class RomFile(models.Model):
@@ -48,3 +51,6 @@ class RomFile(models.Model):
 
     class Meta:
         unique_together = ('rom', 'slot')
+
+    def __str__(self):
+        return "RomFile %s %d" % (self.rom.name, self.slot)