Evaluation of storage of app settings

[Craftplacer]

With Kaiteki growing in complexity, Settings are required to meet the customization demands by users. Currently, Kaiteki doesn't really have a solid way of storing settings, or even a good one for that matter. This discussion is for searching for solutions for that problem.

Requirements

• Easy to maintain
  • No complex code required to add and retrieve settings
  • Auto completion by IDE must be possible
• Should be able to integrate with Kaiteki's state management library riverpod
• Multiple settings will likely be read from the same widget
  • No "value listener" listening only on one preference(?)

Ideas

• Hardcoded setting references/definitions (no hand-written string keys); 2 approaches:
  • Utilise Dart's enhanced enums
  • Define fields/properties inside a class

Solutions

Accessing shared_preferences directly from individual widgets

Advantages

• No complexity

Disadvantages

• Only supports simple data types (bool, int, double, string, string array)
  • Need to add json_serializable to enable storing complex data types
• Somewhat hard to maintain
  • Requires writing and keeping track of keys for settings
  • Impossible to synchronize in the future

sqflite

Advantages

• Organized data in tables
• Designed for large data amounts

Disadvantages

• Overkill since ...
  • SQL queries
  • Columns
• (Seemingly) Complicated to get going in the first place

Adopt e1527's settings system

Advantages

• Seems promising and reliable

Disadvantages

• Overengineered

[ThatOneCalculator]

Imho sqlflite seems like the better choice here conceptually, (afaict most apps with complex settings use SQLite or something similar), while it's more complex it shouldn't be too bad: https://camposha.info/flutter/flutter-sqflite/#gsc.tab=0

[Craftplacer]

My issue with SQLFLite is that it's just straight up unfitting for our use case. We try to store several small fields, they just aren't effective with tables (I don't even know how to store that effectively, are we supposed to do KV columns making this irrelevant altogether?). In addition to that we have to use SQL queries which is far from what I'd actually need.

[ThatOneCalculator]

Is there a way you could connect to a NoSQL/Document-oriented DB?

[Craftplacer]

Random picks:

• https://pub.dev/packages/hive
• https://pub.dev/packages/objectbox
• https://pub.dev/packages/sembast
• https://pub.dev/packages/objectdb
• https://pub.dev/packages/localstore
• https://pub.dev/packages/entity

[a1batross]

Tusky works with settings in that way that SharedPreferences only used for simple global settings, like proxy settings and SQLite db used for everything that's can be bound to an account. This is not good that there are two ways to work with the settings, it can get kinda confusing.

I would store all settings into SQLite database, it's very simple to manage, fast and well-tested solution. For global key-value storage, just a simple table with two string type columns is enough in my opinion. Storing per-account data is more native for relational database nature, of course. SQL isn't that complex as it seems. :)

Also having full-fledged database would be useful to store instance data, statuses and accounts, so data would be accessible offline, which is important on phones.

In the future, it could be possible to just dump two tables, if a user is migrating from one device to another.

[a1batross]

Upd: KV storage for global settings can be with integer keys and blob type value column, sqlite is actually dynamically typed :)

sqlite> .open test.db
sqlite> create table global_kv (key integer primary key, value blob not null);
sqlite> insert into global_kv values(0, "meow");
sqlite> insert into global_kv values(123, 123);
sqlite> insert into global_kv values(456, false);
sqlite> insert into global_kv values(789, 1.0);

sqlite> select value, typeof(value) from global_kv where key=456;
0|integer
sqlite> select value, typeof(value) from global_kv where key=0;
meow|text
sqlite> select value, typeof(value) from global_kv where key=123;
123|integer
sqlite> select value, typeof(value) from global_kv where key=456;
0|integer

[Craftplacer]

We've settled on clragon's settings system with adjustments for Riverpod.