Render Stream Descriptions From the Backend

[Hypro999]

Read about the issue here: #11272

[timabbott]

I think you also need to patch create_stream_if_needed to render the descriptions. And now that I think about it, also do something with populate_db (bulk_create_streams, which creates streams in a hacky way optimized for fast development environment setup, should call the render function too).

[Hypro999]

also do something with populate_db (bulk_create_streams, which creates streams in a hacky way optimized for fast development environment setup, should call the render function too).

Ah, this was what I was looking for. Despite making appropriate changes for the "Update the function that creates a stream" part , my tests weren't passing and after a good debugging session, I knew that it was due to the test data, I just didn't know where to modify it. Thanks for the tip!

[timabbott]

Cool, let me know once you have this fixed (no hurry).

[Hypro999]

@timabbott, I think that the backend portion for this feature is about done. Could you please have a look? P.S. I made more commits than required so that it would be easy to review, when you think that the code looks good, we can squash them accordingly.

[timabbott]

@Hypro999 it looks like you resolve the migrations conflicts incorrectly and renumbered a bunch of existing migrations. That does not work at all. Instead, you want to be renumbering your new migration.

Otherwise, this looks good to me.

[Hypro999]

In retrospect, I realize that renumbering that way was a bad idea. @timabbott, I've fixed it. Is there anything else that might need to be changed? Also, thanks for reviewing!

[Hypro999]

I squashed the commits, rebased with master and updated the commit message.

[timabbott]

This looks great @Hypro999! I made a few changes:

• s/rendered_value/rendered_descriptionin the event format; I think there's a reasonable argument for either approach, but I felt thatrendered_description` would feel more rational to folks writing clients like the mobile apps.
• I applied this change to handle our data import tools:

diff --git a/zerver/data_import/import_util.py b/zerver/data_import/import_util.py
index d843116..fe23713 100644
--- a/zerver/data_import/import_util.py
+++ b/zerver/data_import/import_util.py
@@ -328,6 +328,7 @@ def build_stream(date_created: Any, realm_id: int, name: str,
         name=name,
         deactivated=deactivated,
         description=description,
+        # We don't set rendered_description here; it'll be added on import
         date_created=date_created,
         invite_only=invite_only,
         id=stream_id)
diff --git a/zerver/lib/import_realm.py b/zerver/lib/import_realm.py
index d88268b..e6b0f61 100644
--- a/zerver/lib/import_realm.py
+++ b/zerver/lib/import_realm.py
@@ -22,7 +22,7 @@ from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.lib.export import DATE_FIELDS, \
     Record, TableData, TableName, Field, Path
 from zerver.lib.message import do_render_markdown, RealmAlertWords
-from zerver.lib.bugdown import version as bugdown_version
+from zerver.lib.bugdown import version as bugdown_version, convert as bugdown_convert
 from zerver.lib.upload import random_name, sanitize_name, \
     guess_type, BadImageError
 from zerver.lib.utils import generate_api_key, process_list_in_batches
@@ -742,6 +742,11 @@ def do_import_realm(import_dir: Path, subdomain: str, processes: int=1) -> Realm
     # Stream objects are created by Django.
     fix_datetime_fields(data, 'zerver_stream')
     re_map_foreign_keys(data, 'zerver_stream', 'realm', related_table="realm")
+    # Handle rendering of stream descriptions for import from non-Zulip
+    for stream in data['zerver_stream']:
+        if 'rendered_description' in stream:
+            continue
+        stream["rendered_description"] = bugdown_convert(stream["description"])
     bulk_import_model(data, Stream)
 
     realm.notifications_stream_id = notifications_stream_id

With those changes, merged, thanks @Hypro999! I think this should just leave the UI changes, which I imagine should be fairly simple everywhere except for the stream-edit UI.