**! ! Warning**: Do not merge before testing every API call and database
read involving JSON !
**Gson** is obsolete and has been superseded by **Moshi**. But more
importantly, parsing Kotlin objects using Gson is _dangerous_ because
Gson uses Java serialization and is **not Kotlin-aware**. This has two
main consequences:
- Fields of non-null types may end up null at runtime. Parsing will
succeed, but the code may crash later with a `NullPointerException` when
trying to access a field member;
- Default values of constructor parameters are always ignored. When
absent, reference types will be null, booleans will be false and
integers will be zero.
On the other hand, Kotlin-aware parsers like **Moshi** or **Kotlin
Serialization** will validate at parsing time that all received fields
comply with the Kotlin contract and avoid errors at runtime, making apps
more stable and schema mismatches easier to detect (as long as logs are
accessible):
- Receiving a null value for a non-null type will generate a parsing
error;
- Optional types are declared explicitly by adding a default value. **A
missing value with no default value declaration will generate a parsing
error.**
Migrating the entity declarations from Gson to Moshi will make the code
more robust but is not an easy task because of the semantic differences.
With Gson, both nullable and optional fields are represented with a null
value. After converting to Moshi, some nullable entities can become
non-null with a default value (if they are optional and not nullable),
others can stay nullable with no default value (if they are mandatory
and nullable), and others can become **nullable with a default value of
null** (if they are optional _or_ nullable _or_ both). That third option
is the safest bet when it's not clear if a field is optional or not,
except for lists which can usually be declared as non-null with a
default value of an empty list (I have yet to see a nullable array type
in the Mastodon API).
Fields that are currently declared as non-null present another
challenge. In theory, they should remain as-is and everything will work
fine. In practice, **because Gson is not aware of nullable types at
all**, it's possible that some non-null fields currently hold a null
value in some cases but the app does not report any error because the
field is not accessed by Kotlin code in that scenario. After migrating
to Moshi however, parsing such a field will now fail early if a null
value or no value is received.
These fields will have to be identified by heavily testing the app and
looking for parsing errors (`JsonDataException`) and/or by going through
the Mastodon documentation. A default value needs to be added for
missing optional fields, and their type could optionally be changed to
nullable, depending on the case.
Gson is also currently used to serialize and deserialize objects to and
from the local database, which is also challenging because backwards
compatibility needs to be preserved. Fortunately, by default Gson omits
writing null fields, so a field of type `List<T>?` could be replaced
with a field of type `List<T>` with a default value of `emptyList()` and
reading back the old data should still work. However, nullable lists
that are written directly (not as a field of another object) will still
be serialized to JSON as `"null"` so the deserializing code must still
be handling null properly.
Finally, changing the database schema is out of scope for this pull
request, so database entities that also happen to be serialized with
Gson will keep their original types even if they could be made non-null
as an improvement.
In the end this is all for the best, because the app will be more
reliable and errors will be easier to detect by showing up earlier with
a clear error message. Not to mention the performance benefits of using
Moshi compared to Gson.
- Replace Gson reflection with Moshi Kotlin codegen to generate all
parsers at compile time.
- Replace custom `Rfc3339DateJsonAdapter` with the one provided by
moshi-adapters.
- Replace custom `JsonDeserializer` classes for Enum types with
`EnumJsonAdapter.create(T).withUnknownFallback()` from moshi-adapters to
support fallback values.
- Replace `GuardedBooleanAdapter` with the more generic `GuardedAdapter`
which works with any type. Any nullable field may now be annotated with
`@Guarded`.
- Remove Proguard rules related to Json entities. Each Json entity needs
to be annotated with `@JsonClass` with no exception, and adding this
annotation will ensure that R8/Proguard will handle the entities
properly.
- Replace some nullable Boolean fields with non-null Boolean fields with
a default value where possible.
- Replace some nullable list fields with non-null list fields with a
default value of `emptyList()` where possible.
- Update `TimelineDao` to perform all Json conversions internally using
`Converters` so no Gson or Moshi instance has to be passed to its
methods.
- ~~Create a custom `DraftAttachmentJsonAdapter` to serialize and
deserialize `DraftAttachment` which is a special entity that supports
more than one json name per field. A custom adapter is necessary because
there is not direct equivalent of `@SerializedName(alternate = [...])`
in Moshi.~~ Remove alternate names for some `DraftAttachment` fields
which were used as a workaround to deserialize local data in 2-years old
builds of Tusky.
- Update tests to make them work with Moshi.
- Simplify a few `equals()` implementations.
- Change a few functions to `val`s
- Turn `NetworkModule` into an `object` (since it contains no abstract
methods).
Please test the app thoroughly before merging. There may be some fields
currently declared as mandatory that are actually optional.
* Replace "warn"-filtered posts in timelines and thread view with placeholders
* Adapt hashtag muting interface
* Rework filter UI
* Add icon for account preferences
* Clean up UI
* WIP: Use chips instead of a list. Adjust padding
* Scroll the filter edit activity
Nested scrolling views (e.g., an activity that scrolls with an embedded list
that also scrolls) can be difficult UI.
Since the list of contexts is fixed, replace it with a fixed collection of
switches, so there's no need to scroll the list.
Since the list of actions is only two (warn, hide), and are mutually
exclusive, replace the spinner with two radio buttons.
Use the accent colour and title styles on the different heading titles in
the layout, to match the presentation in Preferences.
Add an explicit "Cancel" button.
The layout is a straightforward LinearLayout, so use that instead of
ConstraintLayout, and remove some unncessary IDs.
Update EditFilterActivity to handle the new layout.
* Cleanup
* Add more information to the filter list view
* First pass on code review comments
* Add view model to filters activity
* Add view model to edit filters activity
* Only use the status wrapper for filtered statuses
* Relint
---------
Co-authored-by: Nik Clayton <nik@ngo.org.uk>
* Add editedAt field to Status
* Status: Display indicators of edited posts
* Annotate edited posts in the Status description
* Cache info that post has been edited
* Add UI for selecting post language
* Apply selected language when sending status
* Save/restore post language with drafts
* Fall back to english if the configured language isn't found in the locale list (no-NB)
* Remove comment about no_NB
* Move language dropdown to top of compose view
* Preserve language when redrafting
* Set default language to target post's language when replying
* Add Tusky license header to new source file
* Tweak language dropdown button width
* Migrate LinkHelper to kotlin
* Support tags field on statuses
* Use embedded tags list in status instead of text scraping to embed tag click handler.
Fixes#2283
* Make mentions and tags lists nonnullable
* Make LinkHelper.openLink a Context extension method
* Use builtin extension for uri conversion
* More cleanup in LinkHelper
* Add tests for LinkHelper.getDomain
* Unbreak tags in places that don't have a tag list (e.g. profiles)
* Fixup javadoc
* first setup
* network timeline paging / improvements
* rename classes / move to correct package
* remove unused class TimelineAdapter
* some code cleanup
* remove TimelineRepository, put mapper functions in TimelineTypeMappers.kt
* add db migration
* cleanup unused code
* bugfix
* make default timeline settings work again
* fix pinning statuses from timeline
* fix network timeline
* respect account settings in NetworkTimelineRemoteMediator
* respect account settings in NetworkTimelineRemoteMediator
* update license headers
* show error view when an error occurs
* cleanup some todos
* fix db migration
* fix changing mediaPreviewEnabled setting
* fix "load more" button appearing on top of timeline
* fix filtering and other bugs
* cleanup cache after 14 days
* fix TimelineDAOTest
* fix code formatting
* add NetworkTimeline unit tests
* add CachedTimeline unit tests
* fix code formatting
* move TimelineDaoTest to unit tests
* implement removeAllByInstance for CachedTimelineViewModel
* fix code formatting
* fix bug in TimelineDao.deleteAllFromInstance
* improve loading more statuses in NetworkTimelineViewModel
* improve loading more statuses in NetworkTimelineViewModel
* fix bug where empty state was shown too soon
* reload top of cached timeline on app start
* improve CachedTimelineRemoteMediator and Tests
* improve cached timeline tests
* fix some more todos
* implement TimelineFragment.removeItem
* fix ListStatusAccessibilityDelegate
* fix crash in NetworkTimelineViewModel.loadMore
* fix default state of collapsible statuses
* fix default state of collapsible statuses -tests
* fix showing/hiding media in the timeline
* get rid of some not-null assertion operators in TimelineTypeMappers
* fix tests
* error handling in CachedTimelineViewModel.loadMore
* keep local status state when refreshing cached statuses
* keep local status state when refreshing network timeline statuses
* show placeholder loading state in cached timeline
* better comments, some code cleanup
* add TimelineViewModelTest, improve code, fix bug
* fix ktlint
* fix voting in boosted polls
* code improvement
Christophe Beyls
Konrad Pozniak
Levi Bard
fruyek
Josh Soref