Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Moved get_component(_unchecked_mut) from Query to QueryState #9686

Merged
Merged
Show file tree
Hide file tree
Changes from 11 commits
Commits
Show all changes
18 commits
Select commit Hold shift + click to select a range
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
128 changes: 128 additions & 0 deletions crates/bevy_ecs/src/query/error.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,128 @@
use std::fmt;

use crate::entity::Entity;

/// An error that occurs when retrieving a specific [`Entity`]'s query result from [`Query`](crate::system::Query) or [`QueryState`](crate::query::QueryState).
// TODO: return the type_name as part of this error
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum QueryEntityError {
/// The given [`Entity`]'s components do not match the query.
///
/// Either it does not have a requested component, or it has a component which the query filters out.
QueryDoesNotMatch(Entity),
/// The given [`Entity`] does not exist.
NoSuchEntity(Entity),
/// The [`Entity`] was requested mutably more than once.
///
/// See [`QueryState::get_many_mut`](crate::query::QueryState::get_many_mut) for an example.
AliasedMutability(Entity),
}

impl std::error::Error for QueryEntityError {}

impl fmt::Display for QueryEntityError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
QueryEntityError::QueryDoesNotMatch(_) => {
write!(f, "The given entity's components do not match the query.")
}
QueryEntityError::NoSuchEntity(_) => write!(f, "The requested entity does not exist."),
QueryEntityError::AliasedMutability(_) => {
write!(f, "The entity was requested mutably more than once.")
}
}
}
}

/// An error that occurs when retrieving a specific [`Entity`]'s component from a [`Query`](crate::system::Query).
#[derive(Debug, PartialEq, Eq)]
pub enum QueryComponentError {
/// The [`Query`](crate::system::Query) does not have read access to the requested component.
///
/// This error occurs when the requested component is not included in the original query.
///
/// # Example
///
/// ```
/// # use bevy_ecs::{prelude::*, query::QueryComponentError};
/// #
/// # #[derive(Component)]
/// # struct OtherComponent;
/// #
/// # #[derive(Component, PartialEq, Debug)]
/// # struct RequestedComponent;
/// #
/// # #[derive(Resource)]
/// # struct SpecificEntity {
/// # entity: Entity,
/// # }
/// #
/// fn get_missing_read_access_error(query: Query<&OtherComponent>, res: Res<SpecificEntity>) {
/// assert_eq!(
/// query.get_component::<RequestedComponent>(res.entity),
/// Err(QueryComponentError::MissingReadAccess),
/// );
/// println!("query doesn't have read access to RequestedComponent because it does not appear in Query<&OtherComponent>");
/// }
/// # bevy_ecs::system::assert_is_system(get_missing_read_access_error);
/// ```
MissingReadAccess,
/// The [`Query`](crate::system::Query) does not have write access to the requested component.
///
/// This error occurs when the requested component is not included in the original query, or the mutability of the requested component is mismatched with the original query.
///
/// # Example
///
/// ```
/// # use bevy_ecs::{prelude::*, query::QueryComponentError};
/// #
/// # #[derive(Component, PartialEq, Debug)]
/// # struct RequestedComponent;
/// #
/// # #[derive(Resource)]
/// # struct SpecificEntity {
/// # entity: Entity,
/// # }
/// #
/// fn get_missing_write_access_error(mut query: Query<&RequestedComponent>, res: Res<SpecificEntity>) {
/// assert_eq!(
/// query.get_component::<RequestedComponent>(res.entity),
/// Err(QueryComponentError::MissingWriteAccess),
/// );
/// println!("query doesn't have write access to RequestedComponent because it doesn't have &mut in Query<&RequestedComponent>");
/// }
/// # bevy_ecs::system::assert_is_system(get_missing_write_access_error);
/// ```
MissingWriteAccess,
/// The given [`Entity`] does not have the requested component.
MissingComponent,
/// The requested [`Entity`] does not exist.
NoSuchEntity,
}

impl std::error::Error for QueryComponentError {}

impl std::fmt::Display for QueryComponentError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match self {
QueryComponentError::MissingReadAccess => {
write!(
f,
"This query does not have read access to the requested component."
)
}
QueryComponentError::MissingWriteAccess => {
write!(
f,
"This query does not have write access to the requested component."
)
}
QueryComponentError::MissingComponent => {
write!(f, "The given entity does not have the requested component.")
}
QueryComponentError::NoSuchEntity => {
write!(f, "The requested entity does not exist.")
}
}
}
}
2 changes: 2 additions & 0 deletions crates/bevy_ecs/src/query/mod.rs
Original file line number Diff line number Diff line change
@@ -1,13 +1,15 @@
//! Contains APIs for retrieving component data from the world.

mod access;
mod error;
mod fetch;
mod filter;
mod iter;
mod par_iter;
mod state;

pub use access::*;
pub use error::*;
pub use fetch::*;
pub use filter::*;
pub use iter::*;
Expand Down
Loading