Do not confuse media column names with question…

types!

This fixes #322 for new schemas, but doesn't yet handle existing schemas
that have a superfluous `None` translation

src/formpack/constants.py

@@ -51,6 +51,14 @@
     'hxl': '',
 }
 
+# Which columns can contain media filenames? Do not confuse this with question
+# types that can collect media! From https://xlsform.org/en/#media:
+#     You can include questions in your form that display images or that play
+#     video or audio files
+#     …
+#     Media is translatable in the same way as labels and hints…
+MEDIA_COLUMN_NAMES = ('audio', 'image', 'video')
+
 # Export Settings
 EXPORT_SETTING_FIELDS = 'fields'
 EXPORT_SETTING_FIELDS_FROM_ALL_VERSIONS = 'fields_from_all_versions'

src/formpack/utils/expand_content.py

@@ -18,8 +18,9 @@
 
 from .array_to_xpath import EXPANDABLE_FIELD_TYPES
 from .iterator import get_first_occurrence
-from .replace_aliases import MEDIA_TYPES, META_TYPES, selects
+from .replace_aliases import META_TYPES, selects
 from ..constants import (
+    MEDIA_COLUMN_NAMES,
     OR_OTHER_COLUMN,
     TAG_COLUMNS_AND_SEPARATORS,
     UNTRANSLATED,
@@ -186,7 +187,7 @@ def _get_known_translated_cols(translated_cols: List[str]) -> List[str]:
 
     _translated_cols = []
     for col in translated_cols:
-        if col in MEDIA_TYPES:
+        if col in MEDIA_COLUMN_NAMES:
             col = f'media::{col}'
         _translated_cols.append(col)
 
@@ -207,7 +208,7 @@ def _get_special_survey_cols(
         'hint::English',
     For more examples, see tests.
     """
-    RE_MEDIA_TYPES = '|'.join(MEDIA_TYPES)
+    RE_MEDIA_COLUMN_NAMES = '|'.join(MEDIA_COLUMN_NAMES)
 
     uniq_cols = OrderedDict()
     special = OrderedDict()
@@ -238,14 +239,14 @@ def _mark_special(**kwargs: str) -> None:
                 column=column_name,
                 translation=UNTRANSLATED,
             )
-        if ':' not in column_name and column_name not in MEDIA_TYPES:
+        if ':' not in column_name and column_name not in MEDIA_COLUMN_NAMES:
             continue
         if column_name.startswith('bind:'):
             continue
         if column_name.startswith('body:'):
             continue
         mtch = re.match(
-            rf'^(media\s*::?\s*)?({RE_MEDIA_TYPES})\s*::?\s*([^:]+)$',
+            rf'^(media\s*::?\s*)?({RE_MEDIA_COLUMN_NAMES})\s*::?\s*([^:]+)$',
             column_name,
         )
         if mtch:
@@ -260,7 +261,9 @@ def _mark_special(**kwargs: str) -> None:
                 translation=translation,
             )
             continue
-        mtch = re.match(rf'^(media\s*::?\s*)?({RE_MEDIA_TYPES})$', column_name)
+        mtch = re.match(
+            rf'^(media\s*::?\s*)?({RE_MEDIA_COLUMN_NAMES})$', column_name
+        )
         if mtch:
             matched = mtch.groups()
             media_type = matched[1]

tests/test_exports.py

@@ -377,6 +377,11 @@ def test_translations_labels_mismatch(self):
             FormPack(schemas, title)
 
     def test_translations_with_select_multiple_from_file(self):
+        """
+        Make sure that exports do not crash if `select_multiple_from_file` is
+        used in a multi-language form. See #322
+        """
+
         title, schemas, submissions = restaurant_profile
 
         # Add a `select_multiple_from_file` question to existing `rpV4` schema
@@ -401,8 +406,14 @@ def test_translations_with_select_multiple_from_file(self):
         # Feed this schema with `file` back into formpack again
         fp = FormPack([fp.versions['rpV4'].schema], title)
 
-        # Fails here with
-        # `formpack.errors.TranslationError: Mismatched labels and translations: [restaurant name, nom du restaurant] [english, french, None] 2!=3`
+        # At this point, issue #322 would have already caused
+        # `TranslationError: Mismatched labels and translations`, but perform a
+        # simple export anyway, adding a response for `suppliers`
+        submissions[-1]['suppliers'] = 'SFG Ocsys'
+        export = fp.export(versions=fp.versions)
+        actual_dict = export.to_dict(submissions)
+        assert actual_dict['Restaurant profile']['fields'][-1] == 'suppliers'
+        assert actual_dict['Restaurant profile']['data'][-1][-1] == 'SFG Ocsys'
 
     def test_simple_nested_grouped_repeatable(self):
         title, schemas, submissions = build_fixture(