emoji: Add which emoji are supported to the /register call.

Fixes #21037.

This is part of fixing #19371. To bulk-add new emoji regularly,
mobile needs to know which servers support which emoji.
`staticfiles_storage.url` generates a unique URL with a hash
based on the file content, which lets mobile know if it needs
to update its locally stored data.

templates/zerver/api/changelog.md

@@ -20,6 +20,11 @@ format used by the Zulip server that they are interacting with.
 
 ## Changes in Zulip 6.0
 
+**Feature level 140**
+
+* [`POST /register`](/api/register-queue): Added string field `server_emoji_data_url`
+  to the response.
+
 **Feature level 139**
 
 * [`GET /get-events`](/api/get-events): When a user mutes or unmutes

tools/setup/emoji/build_emoji

@@ -15,6 +15,7 @@ from emoji_setup_utils import (
     REMAPPED_EMOJIS,
     emoji_names_for_picker,
     generate_codepoint_to_name_map,
+    generate_codepoint_to_names_map,
     generate_emoji_catalog,
     generate_name_to_codepoint_map,
     get_emoji_code,
@@ -332,7 +333,7 @@ def setup_old_emoji_farm(
 
 
 def generate_map_files(cache_path: str, emoji_catalog: Dict[str, List[str]]) -> None:
-    # This function generates the main data file about emoji that are
+    # This function generates the main data files about emoji that are
     # consumed by the web app, mobile apps, Markdown processor, etc.
     names = emoji_names_for_picker(EMOJI_NAME_MAPS)
     codepoint_to_name = generate_codepoint_to_name_map(EMOJI_NAME_MAPS)
@@ -352,6 +353,24 @@ def generate_map_files(cache_path: str, emoji_catalog: Dict[str, List[str]]) ->
             )
         )
 
+    # This is the more official API for mobile to fetch data about emoji.
+    # emoji_codes.json has a lot of goo, and we're creating this new file
+    # as a cleaner data format to move towards. We could add the rest of
+    # the data into this API-described data, and then the web client could
+    # switch to that which would allow us to drop the existing file. But
+    # we'll probably instead do #18121 which will make this file obsolete.
+    # So this is a temporary solution. CZO discussion:
+    # https://chat.zulip.org/#narrow/stream/378-api-design/topic/currently.20supported.20emoji/near/1394598
+    EMOJI_API_FILE_PATH = os.path.join(cache_path, "emoji_api.json")
+    with open(EMOJI_API_FILE_PATH, "wb") as emoji_api_file:
+        emoji_api_file.write(
+            orjson.dumps(
+                {
+                    "code_to_names": generate_codepoint_to_names_map(EMOJI_NAME_MAPS),
+                }
+            )
+        )
+
 
 def dump_emojis(cache_path: str) -> None:
     with open("emoji_map.json", "rb") as emoji_map_file:

tools/setup/emoji/emoji_setup_utils.py

@@ -116,6 +116,19 @@ def generate_codepoint_to_name_map(emoji_name_maps: Dict[str, Dict[str, Any]]) -
     return codepoint_to_name
 
 
+def generate_codepoint_to_names_map(
+    emoji_name_maps: Dict[str, Dict[str, Any]]
+) -> Dict[str, List[str]]:
+    codepoint_to_names: Dict[str, List[str]] = {}
+    for emoji_code, name_info in emoji_name_maps.items():
+        # The first element of the names list is always the canonical name.
+        names = [name_info["canonical_name"]]
+        for alias in name_info["aliases"]:
+            names.append(alias)
+        codepoint_to_names[emoji_code] = names
+    return codepoint_to_names
+
+
 def generate_name_to_codepoint_map(emoji_name_maps: Dict[str, Dict[str, Any]]) -> Dict[str, str]:
     name_to_codepoint = {}
     for emoji_code, name_info in emoji_name_maps.items():

version.py

@@ -33,7 +33,7 @@ DESKTOP_WARNING_VERSION = "5.4.3"
 # Changes should be accompanied by documentation explaining what the
 # new level means in templates/zerver/api/changelog.md, as well as
 # "**Changes**" entries in the endpoint's documentation in `zulip.yaml`.
-API_FEATURE_LEVEL = 139
+API_FEATURE_LEVEL = 140
 
 # Bump the minor PROVISION_VERSION to indicate that folks should provision
 # only when going from an old version of the code to a newer version. Bump

zerver/lib/emoji.py

@@ -3,6 +3,7 @@ import re
 from typing import Tuple
 
 import orjson
+from django.contrib.staticfiles.storage import staticfiles_storage
 from django.utils.translation import gettext as _
 
 from zerver.lib.exceptions import JsonableError
@@ -35,6 +36,15 @@ EMOTICON_RE = (
     + f"))(?![^{terminal_symbols}])"
 )
 
+
+def data_url() -> str:
+    # This bakes a hash into the URL, which looks something like
+    # static/webpack-bundles/files/64.0cdafdf0b6596657a9be.png
+    # This is how Django deals with serving static files in a cacheable way.
+    # See PR #22275 for details.
+    return staticfiles_storage.url("generated/emoji/emoji_api.json")
+
+
 # Translates emoticons to their colon syntax, e.g. `:smiley:`.
 def translate_emoticons(text: str) -> str:
     translated = text

zerver/lib/events.py

@@ -14,6 +14,7 @@ from zerver.actions.default_streams import (
     streams_to_dicts_sorted,
 )
 from zerver.actions.users import get_owned_bot_dicts
+from zerver.lib import emoji
 from zerver.lib.alert_words import user_alert_words
 from zerver.lib.avatar import avatar_url
 from zerver.lib.bot_config import load_bot_config_template
@@ -308,6 +309,8 @@ def fetch_initial_state_data(
         state["server_web_public_streams_enabled"] = settings.WEB_PUBLIC_STREAMS_ENABLED
         state["giphy_rating_options"] = realm.GIPHY_RATING_OPTIONS
 
+        state["server_emoji_data_url"] = emoji.data_url()
+
         state["server_needs_upgrade"] = is_outdated_server(user_profile)
         state[
             "event_queue_longpoll_timeout_seconds"

zerver/openapi/zulip.yaml

@@ -12166,6 +12166,26 @@ paths:
                           (`realm_enable_spectator_access`).
 
                           **Changes**: New in Zulip 5.0 (feature level 110).
+                      server_emoji_data_url:
+                        type: string
+                        description: |
+                          Present if `realm` is present in `fetch_event_types`.
+
+                          The URL to a JSON file that describes which emoji names map to which
+                          emoji codes, for all Unicode emoji this Zulip server accepts.
+
+                          The data at the given URL is a JSON object with one property, `code_to_names`.
+                          The value of that property is a JSON object where each key is an
+                          [emoji code](/api/add-reaction#parameter-emoji_code) for an available
+                          Unicode emoji, and each value is the corresponding
+                          [emoji names](/api/add-reaction#parameter-emoji_name) for this emoji,
+                          with the canonical name for the emoji always appearing first.
+
+                          The HTTP response at that URL will have appropriate HTTP caching headers, such
+                          any HTTP implementation should get a cached version if emoji haven't changed
+                          since the last request.
+
+                          **Changes**: New in Zulip 6.0 (feature level 140).
                       event_queue_longpoll_timeout_seconds:
                         type: integer
                         description: |

zerver/tests/test_home.py

@@ -190,6 +190,7 @@ class HomeTest(ZulipTestCase):
         "request_language",
         "search_pills_enabled",
         "server_avatar_changes_disabled",
+        "server_emoji_data_url",
         "server_generation",
         "server_inline_image_preview",
         "server_inline_url_embed_preview",