Fixed #342 -- added readonly_fields to ModelAdmin. Thanks Alex Gaynor for bootstrapping the patch.

ModelAdmin has been given a readonly_fields that allow field and calculated
values to be displayed alongside editable fields. This works on model
add/change pages and inlines.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11965 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/admin_views/models.py

@@ -1,11 +1,14 @@
 # -*- coding: utf-8 -*-
+import datetime
 import tempfile
 import os
-from django.core.files.storage import FileSystemStorage
-from django.db import models
+
 from django.contrib import admin
+from django.core.files.storage import FileSystemStorage
 from django.contrib.admin.views.main import ChangeList
 from django.core.mail import EmailMessage
+from django.db import models
+
 
 class Section(models.Model):
     """
@@ -419,7 +422,47 @@ class CategoryInline(admin.StackedInline):
     model = Category
 
 class CollectorAdmin(admin.ModelAdmin):
-    inlines = [WidgetInline, DooHickeyInline, GrommetInline, WhatsitInline, FancyDoodadInline, CategoryInline]
+    inlines = [
+        WidgetInline, DooHickeyInline, GrommetInline, WhatsitInline,
+        FancyDoodadInline, CategoryInline
+    ]
+
+class Link(models.Model):
+    posted = models.DateField(
+        default=lambda: datetime.date.today() - datetime.timedelta(days=7)
+    )
+    url = models.URLField()
+    post = models.ForeignKey("Post")
+
+
+class LinkInline(admin.TabularInline):
+    model = Link
+    extra = 1
+
+    readonly_fields = ("posted",)
+
+
+class Post(models.Model):
+    title = models.CharField(max_length=100)
+    content = models.TextField()
+    posted = models.DateField(default=datetime.date.today)
+
+    def awesomeness_level(self):
+        return "Very awesome."
+
+class PostAdmin(admin.ModelAdmin):
+    readonly_fields = ('posted', 'awesomeness_level', 'coolness', lambda obj: "foo")
+
+    inlines = [
+        LinkInline
+    ]
+
+    def coolness(self, instance):
+        if instance.pk:
+            return "%d amount of cool." % instance.pk
+        else:
+            return "Unkown coolness."
+
 
 class Gadget(models.Model):
     name = models.CharField(max_length=100)
@@ -458,6 +501,7 @@ admin.site.register(Recommendation, RecommendationAdmin)
 admin.site.register(Recommender)
 admin.site.register(Collector, CollectorAdmin)
 admin.site.register(Category, CategoryAdmin)
+admin.site.register(Post, PostAdmin)
 admin.site.register(Gadget, GadgetAdmin)
 
 # We intentionally register Promo and ChapterXtra1 but not Chapter nor ChapterXtra2.