Commit graph

21 commits

Author SHA1 Message Date
Clar Fon
711246aa34
Update hashbrown to 0.15 (#15801)
Updating dependencies; adopted version of #15696. (Supercedes #15696.)

Long answer: hashbrown is no longer using ahash by default, meaning that
we can't use the default-hasher methods with ahasher. So, we have to use
the longer-winded versions instead. This takes the opportunity to also
switch our default hasher as well, but without actually enabling the
default-hasher feature for hashbrown, meaning that we'll be able to
change our hasher more easily at the cost of all of these method calls
being obnoxious forever.

One large change from 0.15 is that `insert_unique_unchecked` is now
`unsafe`, and for cases where unsafe code was denied at the crate level,
I replaced it with `insert`.

## Migration Guide

`bevy_utils` has updated its version of `hashbrown` to 0.15 and now
defaults to `foldhash` instead of `ahash`. This means that if you've
hard-coded your hasher to `bevy_utils::AHasher` or separately used the
`ahash` crate in your code, you may need to switch to `foldhash` to
ensure that everything works like it does in Bevy.
2024-12-10 19:45:50 +00:00
Paul Mattern
854934c380
one shot system cleanup (#16516)
# Objective

- Fixes #16497
- This is my first PR, so I'm still learning to contribute to the
project

## Solution

- Added struct `UnregisterSystemCached` and function
`unregister_system_cached`
- renamed `World::run_system_with_input` to `run_system_with`
- reordered input parameters for `World::run_system_once_with`

## Testing

- Added a crude test which registers a system via
`World::register_system_cached`, and removes it via
`Command::unregister_system_cached`.

## Migration Guide

- Change all occurrences of `World::run_system_with_input` to
`World::run_system_with`.
- swap the order of input parameters for `World::run_system_once_with`
such that the system comes before the input.

---------

Co-authored-by: Paul Mattern <mail@paulmattern.dev>
2024-12-10 17:59:42 +00:00
Ben Whitley
7662b4fe40
Fix crash when component parameters are invalid (#16735)
# Objective

Fix the following crash when using BRP to insert a malformed component:

```
thread 'main' panicked at /home/purplg/workspaces/evtc-replay/bevy/crates/bevy_remote/src/builtin_methods.rs:926:18:
called `Result::unwrap()` on an `Err` value: Error("invalid type: map, expected f32", line: 0, column: 0)
```

## Solution

Return an error instead of unwrapping.

## Testing

Tested by sending this malformed payload before and after implementing
the fix:

```json
{
    "jsonrpc": "2.0",
    "id": 0,
    "method": "bevy/insert",
    "params": {
        "entity": 4294967307,
        "components": {
            "bevy_transform::components::transform::Transform": {
                "rotation": [
                    0.0,
                    0.0,
                    0.0,
                    1.0
                ],
                "scale": [
                    1.0,
                    1.0,
                    1.0
                ],
                "translation": [
                    {},
                    0.0,
                    0.0
                ]
            }
        }
    }
}
```

After implementing the fix, I receive the following response instead of
a crash:

```json
{
    "jsonrpc": "2.0",
    "id": 0,
    "error": {
        "code": -23402,
        "message": "bevy_transform::components::transform::Transform is invalid: invalid type: map, expected f32"
    }
}
```
2024-12-10 03:35:28 +00:00
MevLyshkin
5e26429768
BRP serialization tests (#16724)
# Objective

Start work on tests in BRP.

## Solution

- Adds serialization tests to BRP types
2024-12-10 03:33:14 +00:00
MevLyshkin
f59ae0f5e8
BrpQueryRow has field deserialization fix (#16613)
# Objective

BrpQueryRow doesn't serialize `has` field if it is empty. That is okay
until you try to deserialize it after. Then it will fail to deserialize
due to missing field.

## Solution

Serde support using default value when field is missing, this PR adds
that.
2024-12-04 18:26:33 +00:00
Viktor Gustavsson
9f04fc030b
Expose BRP system scheduling and add system set (#16400)
# Objective
When adding custom BRP methods one might need to:
- Run custom systems in the `RemoteLast` schedule.
- Order those systems before/after request processing and cleanup.

For example in `bevy_remote_inspector` we need a way to perform some
preparation _before_ request processing. And to perform cleanup
_between_ request processing and watcher cleanup.

## Solution

- Make `RemoteLast` public
- Add `RemoteSet` with `ProcessRequests` and `Cleanup` variants.
2024-11-16 23:34:06 +00:00
Martín Maita
7fc8318b7f
BRP System Ordering (#16198)
# Objective

- Attempts to fix #16042

## Solution

- Added a new `RemoteSystem` `SystemSet` for the BRP systems.
- Changed the schedule on which these systems run from `Update` to
`Last`.

## Testing

- I did not test these changes and would appreciate a hand in doing so.
I assume it would be good to test that you can order against these
systems easily now.

---

## Migration Guide

- `process_remote_requests`, `process_ongoing_watching_requests` and
`remove_closed_watching_requests` now run in the `Last` schedule. Make
sure you use `RemoteSystem` `SystemSet` in case you need to order your
systems against them.
2024-11-05 21:05:11 +00:00
François Mockers
fac0b34b20
remove reference to missing file in bevy_remote cargo.toml (#16057)
# Objective

- bevy_remote Cargo.toml file references a readme that doesn't exist
- This is blocking releasing the rc

## Solution

- Remove the reference
2024-10-22 20:21:19 +00:00
Liam Gallagher
26a5f7f9ca
Feature gate bevy_remote http transport. (#16019)
## Objective
Be able to depend on the crate for the types without bringing in
`smol-hyper` and other http dependencies.

## Solution

Create a new `HTTP` feature that is enabled by default.
2024-10-20 13:49:55 +00:00
Liam Gallagher
813c75958d
Remove a dbg! statement left over from debugging (#15867)
I wonder who left that there...
2024-10-12 09:07:01 +00:00
Liam Gallagher
f1fbb668f9
Watching versions of bevy/get and bevy/list with HTTP SSE (#15608)
## Objective

Add a way to stream BRP requests when the data changes.

## Solution

#### BRP Side (reusable for other transports)

Add a new method handler type that returns a optional value. This
handler is run in update and if a value is returned it will be sent on
the message channel. Custom watching handlers can be added with
`RemotePlugin::with_watching_method`.

#### HTTP Side

If a request comes in with `+watch` in the method, it will respond with
`text/event-stream` rather than a single response.

## Testing

I tested with the podman HTTP client. This client has good support for
SSE's if you want to test it too.

## Parts I want some opinions on

- For separating watching methods I chose to add a `+watch` suffix to
the end kind of like `content-type` headers. A get would be
`bevy/get+watch`.
- Should watching methods send an initial response with everything or
only respond when a change happens? Currently the later is what happens.

## Future work

- The `bevy/query` method would also benefit from this but that
condition will be quite complex so I will leave that to later.

---------

Co-authored-by: Zachary Harrold <zac@harrold.com.au>
2024-10-08 16:21:46 +00:00
Christian Hughes
584d14808a
Allow World::entity family of functions to take multiple entities and get multiple references back (#15614)
# Objective

Following the pattern established in #15593, we can reduce the API
surface of `World` by providing a single function to grab both a
singular entity reference, or multiple entity references.

## Solution

The following functions can now also take multiple entity IDs and will
return multiple entity references back:
- `World::entity`
- `World::get_entity`
- `World::entity_mut`
- `World::get_entity_mut`
- `DeferredWorld::entity_mut`
- `DeferredWorld::get_entity_mut`

If you pass in X, you receive Y:
- give a single `Entity`, receive a single `EntityRef`/`EntityWorldMut`
(matches current behavior)
- give a `[Entity; N]`/`&[Entity; N]` (array), receive an equally-sized
`[EntityRef; N]`/`[EntityMut; N]`
- give a `&[Entity]` (slice), receive a
`Vec<EntityRef>`/`Vec<EntityMut>`
- give a `&EntityHashSet`, receive a
`EntityHashMap<EntityRef>`/`EntityHashMap<EntityMut>`

Note that `EntityWorldMut` is only returned in the single-entity case,
because having multiple at the same time would lead to UB. Also,
`DeferredWorld` receives an `EntityMut` in the single-entity case
because it does not allow structural access.

## Testing

- Added doc-tests on `World::entity`, `World::entity_mut`, and
`DeferredWorld::entity_mut`
- Added tests for aliased mutability and entity existence

---

## Showcase

<details>
  <summary>Click to view showcase</summary>

The APIs for fetching `EntityRef`s and `EntityMut`s from the `World`
have been unified.

```rust
// This code will be referred to by subsequent code blocks.
let world = World::new();
let e1 = world.spawn_empty().id();
let e2 = world.spawn_empty().id();
let e3 = world.spawn_empty().id();
```

Querying for a single entity remains mostly the same:

```rust
// 0.14
let eref: EntityRef = world.entity(e1);
let emut: EntityWorldMut = world.entity_mut(e1);
let eref: Option<EntityRef> = world.get_entity(e1);
let emut: Option<EntityWorldMut> = world.get_entity_mut(e1);

// 0.15
let eref: EntityRef = world.entity(e1);
let emut: EntityWorldMut = world.entity_mut(e1);
let eref: Result<EntityRef, Entity> = world.get_entity(e1);
let emut: Result<EntityWorldMut, Entity> = world.get_entity_mut(e1);
```

Querying for multiple entities with an array has changed:

```rust
// 0.14
let erefs: [EntityRef; 2] = world.many_entities([e1, e2]);
let emuts: [EntityMut; 2] = world.many_entities_mut([e1, e2]);
let erefs: Result<[EntityRef; 2], Entity> = world.get_many_entities([e1, e2]);
let emuts: Result<[EntityMut; 2], QueryEntityError> = world.get_many_entities_mut([e1, e2]);

// 0.15
let erefs: [EntityRef; 2] = world.entity([e1, e2]);
let emuts: [EntityMut; 2] = world.entity_mut([e1, e2]);
let erefs: Result<[EntityRef; 2], Entity> = world.get_entity([e1, e2]);
let emuts: Result<[EntityMut; 2], EntityFetchError> = world.get_entity_mut([e1, e2]);
```

Querying for multiple entities with a slice has changed:

```rust
let ids = vec![e1, e2, e3]);

// 0.14
let erefs: Result<Vec<EntityRef>, Entity> = world.get_many_entities_dynamic(&ids[..]);
let emuts: Result<Vec<EntityMut>, QueryEntityError> = world.get_many_entities_dynamic_mut(&ids[..]);

// 0.15
let erefs: Result<Vec<EntityRef>, Entity> = world.get_entity(&ids[..]);
let emuts: Result<Vec<EntityMut>, EntityFetchError> = world.get_entity_mut(&ids[..]);
let erefs: Vec<EntityRef> = world.entity(&ids[..]); // Newly possible!
let emuts: Vec<EntityMut> = world.entity_mut(&ids[..]); // Newly possible!
```

Querying for multiple entities with an `EntityHashSet` has changed:

```rust
let set = EntityHashSet::from_iter([e1, e2, e3]);

// 0.14
let emuts: Result<Vec<EntityMut>, QueryEntityError> = world.get_many_entities_from_set_mut(&set);

// 0.15
let emuts: Result<EntityHashMap<EntityMut>, EntityFetchError> = world.get_entity_mut(&set);
let erefs: Result<EntityHashMap<EntityRef>, EntityFetchError> = world.get_entity(&set); // Newly possible!
let emuts: EntityHashMap<EntityMut> = world.entity_mut(&set); // Newly possible!
let erefs: EntityHashMap<EntityRef> = world.entity(&set); // Newly possible!
```

</details>

## Migration Guide

- `World::get_entity` now returns `Result<_, Entity>` instead of
`Option<_>`.
- Use `world.get_entity(..).ok()` to return to the previous behavior.
- `World::get_entity_mut` and `DeferredWorld::get_entity_mut` now return
`Result<_, EntityFetchError>` instead of `Option<_>`.
- Use `world.get_entity_mut(..).ok()` to return to the previous
behavior.
- Type inference for `World::entity`, `World::entity_mut`,
`World::get_entity`, `World::get_entity_mut`,
`DeferredWorld::entity_mut`, and `DeferredWorld::get_entity_mut` has
changed, and might now require the input argument's type to be
explicitly written when inside closures.
- The following functions have been deprecated, and should be replaced
as such:
    - `World::many_entities` -> `World::entity::<[Entity; N]>`
    - `World::many_entities_mut` -> `World::entity_mut::<[Entity; N]>`
    - `World::get_many_entities` -> `World::get_entity::<[Entity; N]>`
- `World::get_many_entities_dynamic` -> `World::get_entity::<&[Entity]>`
- `World::get_many_entities_mut` -> `World::get_entity_mut::<[Entity;
N]>`
- The equivalent return type has changed from `Result<_,
QueryEntityError>` to `Result<_, EntityFetchError>`
- `World::get_many_entities_dynamic_mut` ->
`World::get_entity_mut::<&[Entity]>1
- The equivalent return type has changed from `Result<_,
QueryEntityError>` to `Result<_, EntityFetchError>`
- `World::get_many_entities_from_set_mut` ->
`World::get_entity_mut::<&EntityHashSet>`
- The equivalent return type has changed from `Result<Vec<EntityMut>,
QueryEntityError>` to `Result<EntityHashMap<EntityMut>,
EntityFetchError>`. If necessary, you can still convert the
`EntityHashMap` into a `Vec`.
2024-10-07 15:21:40 +00:00
Chang Guo
e7c1c997ac
simplify adding headers and improve consistency for RemoteHttpPlugin (#15680)
# Objective

- a follow up pr for #15651 

## Solution

- rename add to insert cuz insert make more sense when using a HashMap
and new value overrides previous value based on key (quote:
https://github.com/bevyengine/bevy/pull/15651#discussion_r1788851778)
- use `TryInto<>` for add(insert) as well when constructing `Headers`.
Doing so user won't need to interact with hyper APIs, and `with_headers`
will align better with `with_header` (quote:
https://github.com/bevyengine/bevy/pull/15651#discussion_r1788687251)
- move example usage of Headers to `with_headers` method (quote:
https://github.com/bevyengine/bevy/pull/15651#discussion_r1788989500)

## Testing

- the same as I tested my previous pr
2024-10-06 19:06:19 +00:00
Chang Guo
7c4a0683c7
Add with_headers() method to RemoteHttpPlugin (#15651)
# Objective

- fulfill the needs presented in this issue, which requires the ability
to set custom HTTP headers for responses in the Bevy Remote Protocol
server. #15551

## Solution

- Created a `Headers` struct to store custom HTTP headers as key-value
pairs.
- Added a `headers` field to the `RemoteHttpPlugin` struct.
- Implemented a `with_headers` method in `RemoteHttpPlugin` to allow
users to set custom headers.
- Passed the headers into the processing chain.

## Testing

- I added cors_headers in example/remote/server.rs and tested it with a
static html
[file](https://github.com/spacemen0/bevy/blob/test_file/test.html)

---
2024-10-06 13:21:21 +00:00
notmd
453c0167b2
Allow access a method handler (#15601)
# Objective

- I'm building a streaming plugin for `bevy_remote` and accessing to
builtin method will be very valuable

## Solution

- Add a method to allow access a handler by method name.

## Testing

- CI should pass
2024-10-02 19:45:18 +00:00
Liam Gallagher
85dfd72631
Include errors along side successful components in BRP bevy/get method (#15516)
## Objective

I am using BRP for a web inspector. To get components from a entity is
first do a `bevy/list` on the specific entity and then use the result in
a `bevy/get` request. The problem with this is `bevy/list` returns all
components even if they aren't reflect-able (which is what I expect) but
when I then do a `bevy/get` request even if all bar one of the
components are reflect-able the request will fail.

## Solution

Update the `bevy/get` response to include a map of components like it
did for successful request and a map of errors. This means if one or
more components are not present on the entity or cannot be reflected it
will not fail the entire request.

I also only did `bevy/get` as I don't think any of the other methods
would benefit from this.

## Testing

I tested this with my inspector and with a http client and it worked as
expected.

---------

Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
2024-10-02 02:26:01 +00:00
Liam Gallagher
10068f4a26
Add content-type header to BRP HTTP responses (#15552)
This makes HTTP clients like httpie format the response as JSON rather
than text for a much nicer experience testing things.
2024-09-30 21:23:55 +00:00
Liam Gallagher
60cf7ca025
Refactor BRP to allow for 3rd-party transports (#15438)
## Objective

Closes #15408 (somewhat)

## Solution

- Moved the existing HTTP transport to its own module with its own
plugin (`RemoteHttpPlugin`) (disabled on WASM)
- Swapped out the `smol` crate for the smaller crates it re-exports to
make it easier to keep out non-wasm code (HTTP transport needs
`async-io` which can't build on WASM)
- Added a new public `BrpSender` resource holding the matching sender
for the `BrpReceiver`' (formally `BrpMailbox`). This allows other crates
to send `BrpMessage`'s to the "mailbox".

## Testing

TODO

---------

Co-authored-by: Matty <weatherleymatthew@gmail.com>
2024-09-27 20:09:46 +00:00
Zachary Harrold
d70595b667
Add core and alloc over std Lints (#15281)
# Objective

- Fixes #6370
- Closes #6581

## Solution

- Added the following lints to the workspace:
  - `std_instead_of_core`
  - `std_instead_of_alloc`
  - `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.

## Testing

- Ran CI locally

## Migration Guide

The MSRV is now 1.81. Please update to this version or higher.

## Notes

- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.

---------

Co-authored-by: François Mockers <francois.mockers@vleue.com>
2024-09-27 00:59:59 +00:00
Clar Fon
efda7f3f9c
Simpler lint fixes: makes ci lints work but disables a lint for now (#15376)
Takes the first two commits from #15375 and adds suggestions from this
comment:
https://github.com/bevyengine/bevy/pull/15375#issuecomment-2366968300

See #15375 for more reasoning/motivation.

## Rebasing (rerunning)

```rust
git switch simpler-lint-fixes
git reset --hard main
cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate
cargo fmt --all
git add --update
git commit --message "rustfmt"
cargo clippy --workspace --all-targets --all-features --fix
cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate
cargo fmt --all
git add --update
git commit --message "clippy"
git cherry-pick e6c0b94f6795222310fb812fa5c4512661fc7887
```
2024-09-24 11:42:59 +00:00
Matty
89e98b208f
Initial implementation of the Bevy Remote Protocol (Adopted) (#14880)
# Objective

Adopted from #13563.

The goal is to implement the Bevy Remote Protocol over HTTP/JSON,
allowing the ECS to be interacted with remotely.

## Solution

At a high level, there are really two separate things that have been
undertaken here:
1. First, `RemotePlugin` has been created, which has the effect of
embedding a [JSON-RPC](https://www.jsonrpc.org/specification) endpoint
into a Bevy application.
2. Second, the [Bevy Remote Protocol
verbs](https://gist.github.com/coreh/1baf6f255d7e86e4be29874d00137d1d#file-bevy-remote-protocol-md)
(excluding `POLL`) have been implemented as remote methods for that
JSON-RPC endpoint under a Bevy-exclusive namespace (e.g. `bevy/get`,
`bevy/list`, etc.).

To avoid some repetition, here is the crate-level documentation, which
explains the request/response structure, built-in-methods, and custom
method configuration:
<details>
  <summary>Click to view crate-level docs</summary>

```rust
//! An implementation of the Bevy Remote Protocol over HTTP and JSON, to allow
//! for remote control of a Bevy app.
//!
//! Adding the [`RemotePlugin`] to your [`App`] causes Bevy to accept
//! connections over HTTP (by default, on port 15702) while your app is running.
//! These *remote clients* can inspect and alter the state of the
//! entity-component system. Clients are expected to `POST` JSON requests to the
//! root URL; see the `client` example for a trivial example of use.
//!
//! The Bevy Remote Protocol is based on the JSON-RPC 2.0 protocol.
//!
//! ## Request objects
//!
//! A typical client request might look like this:
//!
//! ```json
//! {
//!     "method": "bevy/get",
//!     "id": 0,
//!     "params": {
//!         "entity": 4294967298,
//!         "components": [
//!             "bevy_transform::components::transform::Transform"
//!         ]
//!     }
//! }
//! ```
//!
//! The `id` and `method` fields are required. The `param` field may be omitted
//! for certain methods:
//!
//! * `id` is arbitrary JSON data. The server completely ignores its contents,
//!   and the client may use it for any purpose. It will be copied via
//!   serialization and deserialization (so object property order, etc. can't be
//!   relied upon to be identical) and sent back to the client as part of the
//!   response.
//!
//! * `method` is a string that specifies one of the possible [`BrpRequest`]
//!   variants: `bevy/query`, `bevy/get`, `bevy/insert`, etc. It's case-sensitive.
//!
//! * `params` is parameter data specific to the request.
//!
//! For more information, see the documentation for [`BrpRequest`].
//! [`BrpRequest`] is serialized to JSON via `serde`, so [the `serde`
//! documentation] may be useful to clarify the correspondence between the Rust
//! structure and the JSON format.
//!
//! ## Response objects
//!
//! A response from the server to the client might look like this:
//!
//! ```json
//! {
//!     "jsonrpc": "2.0",
//!     "id": 0,
//!     "result": {
//!         "bevy_transform::components::transform::Transform": {
//!             "rotation": { "x": 0.0, "y": 0.0, "z": 0.0, "w": 1.0 },
//!             "scale": { "x": 1.0, "y": 1.0, "z": 1.0 },
//!             "translation": { "x": 0.0, "y": 0.5, "z": 0.0 }
//!         }
//!     }
//! }
//! ```
//!
//! The `id` field will always be present. The `result` field will be present if the
//! request was successful. Otherwise, an `error` field will replace it.
//!
//! * `id` is the arbitrary JSON data that was sent as part of the request. It
//!   will be identical to the `id` data sent during the request, modulo
//!   serialization and deserialization. If there's an error reading the `id` field,
//!   it will be `null`.
//!
//! * `result` will be present if the request succeeded and will contain the response
//!   specific to the request.
//!
//! * `error` will be present if the request failed and will contain an error object
//!   with more information about the cause of failure.
//!
//! ## Error objects
//!
//! An error object might look like this:
//!
//! ```json
//! {
//!     "code": -32602,
//!     "message": "Missing \"entity\" field"
//! }
//! ```
//!
//! The `code` and `message` fields will always be present. There may also be a `data` field.
//!
//! * `code` is an integer representing the kind of an error that happened. Error codes documented
//!   in the [`error_codes`] module.
//!
//! * `message` is a short, one-sentence human-readable description of the error.
//!
//! * `data` is an optional field of arbitrary type containing additional information about the error.
//!
//! ## Built-in methods
//!
//! The Bevy Remote Protocol includes a number of built-in methods for accessing and modifying data
//! in the ECS. Each of these methods uses the `bevy/` prefix, which is a namespace reserved for
//! BRP built-in methods.
//!
//! ### bevy/get
//!
//! Retrieve the values of one or more components from an entity.
//!
//! `params`:
//! - `entity`: The ID of the entity whose components will be fetched.
//! - `components`: An array of fully-qualified type names of components to fetch.
//!
//! `result`: A map associating each type name to its value on the requested entity.
//!
//! ### bevy/query
//!
//! Perform a query over components in the ECS, returning all matching entities and their associated
//! component values.
//!
//! All of the arrays that comprise this request are optional, and when they are not provided, they
//! will be treated as if they were empty.
//!
//! `params`:
//! `params`:
//! - `data`:
//!   - `components` (optional): An array of fully-qualified type names of components to fetch.
//!   - `option` (optional): An array of fully-qualified type names of components to fetch optionally.
//!   - `has` (optional): An array of fully-qualified type names of components whose presence will be
//!      reported as boolean values.
//! - `filter` (optional):
//!   - `with` (optional): An array of fully-qualified type names of components that must be present
//!     on entities in order for them to be included in results.
//!   - `without` (optional): An array of fully-qualified type names of components that must *not* be
//!     present on entities in order for them to be included in results.
//!
//! `result`: An array, each of which is an object containing:
//! - `entity`: The ID of a query-matching entity.
//! - `components`: A map associating each type name from `components`/`option` to its value on the matching
//!   entity if the component is present.
//! - `has`: A map associating each type name from `has` to a boolean value indicating whether or not the
//!   entity has that component. If `has` was empty or omitted, this key will be omitted in the response.
//!
//! ### bevy/spawn
//!
//! Create a new entity with the provided components and return the resulting entity ID.
//!
//! `params`:
//! - `components`: A map associating each component's fully-qualified type name with its value.
//!
//! `result`:
//! - `entity`: The ID of the newly spawned entity.
//!
//! ### bevy/destroy
//!
//! Despawn the entity with the given ID.
//!
//! `params`:
//! - `entity`: The ID of the entity to be despawned.
//!
//! `result`: null.
//!
//! ### bevy/remove
//!
//! Delete one or more components from an entity.
//!
//! `params`:
//! - `entity`: The ID of the entity whose components should be removed.
//! - `components`: An array of fully-qualified type names of components to be removed.
//!
//! `result`: null.
//!
//! ### bevy/insert
//!
//! Insert one or more components into an entity.
//!
//! `params`:
//! - `entity`: The ID of the entity to insert components into.
//! - `components`: A map associating each component's fully-qualified type name with its value.
//!
//! `result`: null.
//!
//! ### bevy/reparent
//!
//! Assign a new parent to one or more entities.
//!
//! `params`:
//! - `entities`: An array of entity IDs of entities that will be made children of the `parent`.
//! - `parent` (optional): The entity ID of the parent to which the child entities will be assigned.
//!   If excluded, the given entities will be removed from their parents.
//!
//! `result`: null.
//!
//! ### bevy/list
//!
//! List all registered components or all components present on an entity.
//!
//! When `params` is not provided, this lists all registered components. If `params` is provided,
//! this lists only those components present on the provided entity.
//!
//! `params` (optional):
//! - `entity`: The ID of the entity whose components will be listed.
//!
//! `result`: An array of fully-qualified type names of components.
//!
//! ## Custom methods
//!
//! In addition to the provided methods, the Bevy Remote Protocol can be extended to include custom
//! methods. This is primarily done during the initialization of [`RemotePlugin`], although the
//! methods may also be extended at runtime using the [`RemoteMethods`] resource.
//!
//! ### Example
//! ```ignore
//! fn main() {
//!     App::new()
//!         .add_plugins(DefaultPlugins)
//!         .add_plugins(
//!             // `default` adds all of the built-in methods, while `with_method` extends them
//!             RemotePlugin::default()
//!                 .with_method("super_user/cool_method".to_owned(), path::to::my:🆒:handler)
//!                 // ... more methods can be added by chaining `with_method`
//!         )
//!         .add_systems(
//!             // ... standard application setup
//!         )
//!         .run();
//! }
//! ```
//!
//! The handler is expected to be a system-convertible function which takes optional JSON parameters
//! as input and returns a [`BrpResult`]. This means that it should have a type signature which looks
//! something like this:
//! ```
//! # use serde_json::Value;
//! # use bevy_ecs::prelude::{In, World};
//! # use bevy_remote::BrpResult;
//! fn handler(In(params): In<Option<Value>>, world: &mut World) -> BrpResult {
//!     todo!()
//! }
//! ```
//!
//! Arbitrary system parameters can be used in conjunction with the optional `Value` input. The
//! handler system will always run with exclusive `World` access.
//!
//! [the `serde` documentation]: https://serde.rs/
```

</details>

### Message lifecycle

At a high level, the lifecycle of client-server interactions is
something like this:
1. The client sends one or more `BrpRequest`s. The deserialized version
of that is just the Rust representation of a JSON-RPC request, and it
looks like this:
```rust
pub struct BrpRequest {
    /// The action to be performed. Parsing is deferred for the sake of error reporting.
    pub method: Option<Value>,

    /// Arbitrary data that will be returned verbatim to the client as part of
    /// the response.
    pub id: Option<Value>,

    /// The parameters, specific to each method.
    ///
    /// These are passed as the first argument to the method handler.
    /// Sometimes params can be omitted.
    pub params: Option<Value>,
}
```
2. These requests are accumulated in a mailbox resource (small lie but
close enough).
3. Each update, the mailbox is drained by a system
`process_remote_requests`, where each request is processed according to
its `method`, which has an associated handler. Each handler is a Bevy
system that runs with exclusive world access and returns a result; e.g.:
```rust
pub fn process_remote_get_request(In(params): In<Option<Value>>, world: &World) -> BrpResult { // ... }
```
4. The result (or an error) is reported back to the client.

## Testing

This can be tested by using the `server` and `client` examples. The
`client` example is not particularly exhaustive at the moment (it only
creates barebones `bevy/query` requests) but is still informative. Other
queries can be made using `curl` with the `server` example running.

For example, to make a `bevy/list` request and list all registered
components:
```bash
curl -X POST -d '{ "jsonrpc": "2.0", "id": 1, "method": "bevy/list" }' 127.0.0.1:15702 | jq .
```

---

## Future direction

There were a couple comments on BRP versioning while this was in draft.
I agree that BRP versioning is a good idea, but I think that it requires
some consensus on a couple fronts:
- First of all, what does the version actually mean? Is it a version for
the protocol itself or for the `bevy/*` methods implemented using it?
Both?
- Where does the version actually live? The most natural place is just
where we have `"jsonrpc"` right now (at least if it's versioning the
protocol itself), but this means we're not actually conforming to
JSON-RPC any more (so, for example, any client library used to construct
JSON-RPC requests would stop working). I'm not really against that, but
it's at least a real decision.
- What do we actually do when we encounter mismatched versions? Adding
handling for this would be actual scope creep instead of just a little
add-on in my opinion.

Another thing that would be nice is making the internal structure of the
implementation less JSON-specific. Right now, for example, component
values that will appear in server responses are quite eagerly converted
to JSON `Value`s, which prevents disentangling the handler logic from
the communication medium, but it can probably be done in principle and I
imagine it would enable more code reuse (e.g. for custom method
handlers) in addition to making the internals more readily usable for
other formats.

---------

Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
Co-authored-by: DragonGamesStudios <margos.michal@gmail.com>
Co-authored-by: Christopher Biscardi <chris@christopherbiscardi.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2024-09-23 18:36:16 +00:00