Featture toggles for Rust (called "feattles", for short), extensible and with background synchronization and administration UI.
```rust use rusotos3::S3Client; use rusotocore::Region; use feattle::*; use std::sync::Arc;
/// A struct with your feature toggles: you can use primitive types (like bool, i32, etc),
/// standard collections (like Vec, BTreeSet, etc) or any arbitrary type that implements
/// the required trait.
feattles! {
struct MyFeattles {
/// Is this usage considered cool?
iscool: bool = true,
/// Limit the number of "blings" available.
/// This will not change the number of "blengs", though!
maxblings: i32,
/// List the actions that should not be available
blocked_actions: Vec
// Store their values and history in AWS' S3 let s3client = S3Client::new(Region::default()); let persistence = S3::new(s3client, "my-bucket".toowned(), "some/s3/prefix/".toowned());
// Create a new instance let my_feattles = Arc::new(MyFeattles::new(persistence));
// Poll the storage in the background BackgroundSync::new(&my_feattles).spawn();
// Start the admin UI with warp
let adminpanel = Arc::new(AdminPanel::new(myfeattles.clone(), "Project Panda - DEV".toowned()));
tokio::spawn(runwarpserver(adminpanel, ([127, 0, 0, 1], 3030)));
// Read values (note the use of *)
asserteq!(*myfeattles.iscool(), true);
asserteq!(my_feattles.max_blings(), 0);
assert_eq!(myfeattles.blockedactions(), Vec::
You can run a full example locally with: cargo run --example full --features='s3 uuid warp'.
With this code, you'll get an Web Admin UI like:
You can use the UI to edit the current values and see their change history. For example, this
is what you can expect when editing an enum:
It also supports complex types with a JSON editor and helpful error diagnostics:
The macro will generate a struct with the given name and visibility modifier (assuming private
by default). The generated struct implements [Feattles] and also exposes one method for each
feattle.
The methods created for each feattle allow reading their current value. For example, for a
feattle is_cool: bool, there will be a method like
pub fn is_cool(&self) -> MappedRwLockReadGuard<bool>. Note the use of
[parking_lot::MappedRwLockReadGuard] because the interior of the struct is stored behind a RwLock to
control concurrent access.
A feattle is created with the syntax $key: $type [= $default]. You can use doc coments (
starting with ///) to describe nicely what they do in your system. You can use any type that
implements [FeattleValue] and optionally provide a default. If not provided, the default
will be created with Default::default().
As of this release, the MSRV is 1.42.0, as tested in the CI. A patch release will never require a newer MSRV.
You can easily declare feattles with your custom types, use another persistance storage logic or Web Framework (or any at all). For some out-of-the-box functionality, you can activate these cargo features:
uuid::Uuid].S3] to integrate with AWS' S3run_warp_server] for a read-to-use integration with [warp]This crate is a simple re-export of these three components:
feattle-core: 
feattle-sync: 
feattle-ui: 
Having them separate allows for leaner lower-level integration. If you're creating a crate to
provide a different storage or admin, you just need feattle-core.
Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
See CONTRIBUTING.md.