8cdd977a12
# Objective - Make it impossible to add a plugin twice - This is going to be more a risk for plugins with configurations, to avoid things like `App::new().add_plugins(DefaultPlugins).add_plugin(ImagePlugin::default_nearest())` ## Solution - Panic when a plugin is added twice - It's still possible to mark a plugin as not unique by overriding `is_unique` - ~~Simpler version of~~ #3988 (not simpler anymore because of how `PluginGroupBuilder` implements `PluginGroup`)
58 lines
1.6 KiB
Rust
58 lines
1.6 KiB
Rust
//! Demonstrates the creation and registration of a custom plugin group.
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//! [`PluginGroup`]s are a way to group sets of plugins that should be registered together.
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use bevy::{app::PluginGroupBuilder, prelude::*};
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fn main() {
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App::new()
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// Two PluginGroups that are included with bevy are DefaultPlugins and MinimalPlugins
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.add_plugins(DefaultPlugins)
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// Adding a plugin group adds all plugins in the group by default
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.add_plugins(HelloWorldPlugins)
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// You can also modify a PluginGroup (such as disabling plugins) like this:
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// .add_plugins(
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// HelloWorldPlugins
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// .build()
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// .disable::<PrintWorldPlugin>()
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// .add_before::<PrintHelloPlugin, _>(
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// bevy::diagnostic::LogDiagnosticsPlugin::default(),
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// ),
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// )
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.run();
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}
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/// A group of plugins that produce the "hello world" behavior
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pub struct HelloWorldPlugins;
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impl PluginGroup for HelloWorldPlugins {
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fn build(self) -> PluginGroupBuilder {
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PluginGroupBuilder::start::<Self>()
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.add(PrintHelloPlugin)
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.add(PrintWorldPlugin)
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}
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}
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pub struct PrintHelloPlugin;
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impl Plugin for PrintHelloPlugin {
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fn build(&self, app: &mut App) {
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app.add_system(print_hello_system);
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}
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}
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fn print_hello_system() {
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info!("hello");
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}
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pub struct PrintWorldPlugin;
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impl Plugin for PrintWorldPlugin {
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fn build(&self, app: &mut App) {
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app.add_system(print_world_system);
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}
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}
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fn print_world_system() {
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info!("world");
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}
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