extends localized string export options to group by language

- also adds default templates: `robots.txt`, `data.json`
- adds `json_file_download` view for easily rendering a downloadable JSON file response
- allows `jsondumps` template filter to take in an arg for `indent`

apps/i18n/models.py

@@ -119,7 +119,9 @@ class Meta:
         )
 
     def __str__(self):
-        value = '{} - {}'.format(
-            self.localizable_string.key, self.language_code
-        )
+        value = '{} - {}'.format(self.key, self.language_code)
         return value
+
+    @property
+    def key(self):
+        return self.localizable_string.key

apps/i18n/utils/data.py

@@ -1,6 +1,7 @@
 # Python Standard Library Imports
 import json
 import os
+from functools import lru_cache
 
 # HTK Imports
 from htk.utils import (
@@ -9,23 +10,103 @@
 )
 
 
-def retrieve_all_strings():
-    LocalizableString = resolve_model_dynamically(
-        htk_setting('HTK_LOCALIZABLE_STRING_MODEL')
+@lru_cache
+def look_up_supported_languages():
+    """Looks up which have languages have translations.
+
+    Returns a list of language codes.
+    """
+    LocalizedString = resolve_model_dynamically(
+        htk_setting('HTK_LOCALIZED_STRING_MODEL')
+    )
+    language_codes = (
+        LocalizedString.objects.values_list('language_code', flat=True)
+        .order_by('language_code')
+        .distinct()
     )
-    localizable_strings = LocalizableString.objects.order_by('key')
-    data = {
-        localizable_string.key: localizable_string.json_encode(
-            include_key=False
-        )['translations']
-        for localizable_string in localizable_strings
+    return language_codes
+
+
+def retrieve_all_strings(by_language=False, language_codes=None):
+    """Returns all translated strings for every possible
+    `LocalizableString` in every available language (`LocalizedString`)
+
+    When `by_language` is `False` (default):
+    - All `LocalizableString`s will be included, including those which
+    have no translations available.
+    - The strings will be ordered by `key`s
+
+    The use case for including untranslated strings is to be able to send
+    a batch of strings to translation vendors in bulk.
+
+    Example structure:
+
+    {
+        'bad': {
+            'en-US': 'Bad',
+            'zh-CN': '壞',
+        },
+        'good': {
+            'en-US': 'Good',
+            'zh-CN': '好',
+        },
+    }
+
+    When `by_language` is `True`:
+    - The strings will be ordered by `language_code`
+    - Additionally, if `language_codes` is supplied, only the included languages
+      will be output
+
+    Example structure:
+
+    {
+        'en-US': {
+            'bad': 'Bad',
+            'good': 'Good',
+        },
+        'zh-CN': {
+            'bad': '壞',
+            'good': '好',
+        },
     }
 
+    """
+    if by_language:
+        if language_codes is None:
+            language_codes = look_up_supported_languages()
+
+        LocalizedString = resolve_model_dynamically(
+            htk_setting('HTK_LOCALIZED_STRING_MODEL')
+        )
+
+        data = {
+            language_code: {
+                localized_string.key: localized_string.value
+                for localized_string in LocalizedString.objects.filter(
+                    language_code=language_code
+                ).order_by('localizable_string__key')
+            }
+            for language_code in language_codes
+        }
+    else:
+        LocalizableString = resolve_model_dynamically(
+            htk_setting('HTK_LOCALIZABLE_STRING_MODEL')
+        )
+        localizable_strings = LocalizableString.objects.order_by('key')
+        data = {
+            localizable_string.key: localizable_string.json_encode(
+                include_key=False
+            )['translations']
+            for localizable_string in localizable_strings
+        }
+
     return data
 
 
-def dump_strings(file_path, indent=4):
-    data = retrieve_all_strings()
+def dump_strings(file_path, indent=4, by_language=False, language_codes=None):
+    data = retrieve_all_strings(
+        by_language=False, language_codes=language_codes
+    )
 
     dir_name = os.path.dirname(file_path)
     os.makedirs(dir_name, exist_ok=True)

templates/data.json

@@ -0,0 +1 @@
+{% load htk_tags %}{{ json|jsondumps:4 }}

templates/robots.txt

@@ -0,0 +1,13 @@
+{% spaceless %}
+{% if request.host == constants.canonical_domain %}
+User-agent: *
+Disallow: /admin
+
+Crawl-delay: 10
+Sitemap: https://{{ request.host }}/sitemap.xml
+Host: {{ request.host }}
+{% else %}
+User-agent: *
+Disallow: /
+{% endif %}
+{% endspaceless %}