template_name can be a list of templates passed to loader.select_template. Thanks to zifot for the suggestion.

Author: toastdriven

haystack/fields.py

@@ -119,11 +119,14 @@ def prepare_template(self, obj):
             raise SearchFieldError("This field requires either its instance_name variable to be populated or an explicit template_name in order to load the correct template.")
 
         if self.template_name is not None:
-            template_name = self.template_name
+            template_names = self.template_name
+            
+            if not isinstance(template_names, (list, tuple)):
+                template_names = [template_names]
         else:
-            template_name = 'search/indexes/%s/%s_%s.txt' % (obj._meta.app_label, obj._meta.module_name, self.instance_name)
+            template_names = ['search/indexes/%s/%s_%s.txt' % (obj._meta.app_label, obj._meta.module_name, self.instance_name)]
 
-        t = loader.get_template(template_name)
+        t = loader.select_template(template_names)
         return t.render(Context({'object': obj}))
 
     def convert(self, value):

tests/core/templates/search/indexes/bar.txt

@@ -0,0 +1 @@
+BAR!

tests/core/templates/search/indexes/foo.txt

@@ -0,0 +1 @@
+FOO!

tests/core/tests/fields.py

@@ -232,6 +232,10 @@ def test_init(self):
 
         foo = CharField(use_template=True, template_name='foo.txt')
         self.assertEqual(foo.template_name, 'foo.txt')
+        
+        # Test the select_template usage.
+        foo = CharField(use_template=True, template_name=['bar.txt', 'foo.txt'])
+        self.assertEqual(foo.template_name, ['bar.txt', 'foo.txt'])
 
     def test_prepare(self):
         mock = MockModel()
@@ -248,6 +252,14 @@ def test_prepare(self):
         template3 = CharField(use_template=True)
         template3.instance_name = 'template'
         self.assertEqual(template3.prepare(mock), u'Indexed!\n1')
+        
+        template4 = CharField(use_template=True, template_name='search/indexes/foo.txt')
+        template4.instance_name = 'template'
+        self.assertEqual(template4.prepare(mock), u'FOO!\n')
+        
+        template5 = CharField(use_template=True, template_name=['foo.txt', 'search/indexes/bar.txt'])
+        template5.instance_name = 'template'
+        self.assertEqual(template5.prepare(mock), u'BAR!\n')
 
 
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