Add option to exclude the Select2 library from form media (#484)

django_select2/conf.py

@@ -62,6 +62,11 @@ class Select2Conf(AppConf):
 
         SELECT2_JS = 'assets/js/select2.min.js'
 
+    If you provide your own JS and would not like Django-Select2 to load any, change
+    this setting to a blank string like so::
+
+        SELECT2_JS = ''
+
     .. tip:: Change this setting to a local asset in your development environment to
         develop without an Internet connection.
     """
@@ -75,6 +80,11 @@ class Select2Conf(AppConf):
 
         SELECT2_CSS = 'assets/css/select2.css'
 
+    If you provide your own CSS and would not like Django-Select2 to load any, change
+    this setting to a blank string like so::
+
+        SELECT2_CSS = ''
+
     .. tip:: Change this setting to a local asset in your development environment to
         develop without an Internet connection.
     """

django_select2/forms.py

@@ -100,6 +100,9 @@ class Select2Mixin(object):
         """
         lang = get_language()
         i18n_name = None
+        select2_js = (settings.SELECT2_JS,) if settings.SELECT2_JS else ()
+        select2_css = (settings.SELECT2_CSS,) if settings.SELECT2_CSS else ()
+
         try:
             from django.contrib.admin.widgets import SELECT2_TRANSLATIONS
             i18n_name = SELECT2_TRANSLATIONS.get(lang)
@@ -116,8 +119,8 @@ class Select2Mixin(object):
         i18n_file = ('%s/%s.js' % (settings.SELECT2_I18N_PATH, i18n_name),) if i18n_name else ()
 
         return forms.Media(
-            js=(settings.SELECT2_JS,) + i18n_file + ('django_select2/django_select2.js',),
-            css={'screen': (settings.SELECT2_CSS,)}
+            js=select2_js + i18n_file + ('django_select2/django_select2.js',),
+            css={'screen': select2_css}
         )
 
     media = property(_get_media)

tests/test_forms.py

@@ -161,12 +161,24 @@ class TestSelect2MixinSettings(object):
         assert 'alternate.js' in result
         assert 'django_select2/django_select2.js' in result
 
+    def test_empty_js_setting(self, settings):
+        settings.SELECT2_JS = ''
+        sut = Select2Widget()
+        result = sut.media.render()
+        assert 'django_select2/django_select2.js' in result
+
     def test_css_setting(self, settings):
         settings.SELECT2_CSS = 'alternate.css'
         sut = Select2Widget()
         result = sut.media.render()
         assert 'alternate.css' in result
 
+    def test_empty_css_setting(self, settings):
+        settings.SELECT2_CSS = ''
+        sut = Select2Widget()
+        result = sut.media.render()
+        assert '.css' not in result
+
 
 class TestHeavySelect2Mixin(TestSelect2Mixin):
     url = reverse('heavy_select2_widget')