examples/entities/
entity_iterate_components.rs

1use crate::z_ignore_test_common::*;
2
3use flecs_ecs::prelude::*;
4
5#[derive(Debug, Component)]
6pub struct Position {
7    pub x: f32,
8    pub y: f32,
9}
10
11#[derive(Debug, Component)]
12pub struct Velocity {
13    pub x: f32,
14    pub y: f32,
15}
16
17#[derive(Component)]
18pub struct Eats;
19
20#[derive(Component)]
21pub struct Apples;
22
23#[derive(Component)]
24pub struct Human;
25
26fn iterate_components(entity: EntityView) {
27    // 1. The easiest way to print the components is to use archetype
28    println!("[{:?}]", entity.archetype());
29    println!();
30    // 2. To get individual component ids, use for_each
31    let mut count_components = 0;
32    entity.each_component(|id| {
33        println!("{}: {}", count_components, id.to_str());
34        count_components += 1;
35    });
36    println!();
37
38    // 3. we can also inspect and print the ids in our own way. This is a
39    // bit more complicated as we need to handle the edge cases of what can be
40    // encoded in an id, but provides the most flexibility.
41    count_components = 0;
42
43    entity.each_component(|id| {
44        let mut string: String = String::new();
45        string.push_str(format!("{count_components}: ").as_str());
46
47        count_components += 1;
48        if id.is_pair() {
49            // If id is a pair, extract & print both parts of the pair
50            let rel = id.first_id();
51            let target = id.second_id();
52            string.push_str(format!("rel: {}, target: {}", rel.name(), target.name()).as_str());
53        } else {
54            // Id contains a regular entity. Strip role before printing.
55            let comp = id.entity_view();
56            string.push_str(format!("entity: {}", comp.name()).as_str());
57        }
58
59        println!("{string}");
60    });
61}
62
63fn main() {
64    let world = World::new();
65
66    let bob = world
67        .entity_named("Bob")
68        .set(Position { x: 10.0, y: 20.0 })
69        .set(Velocity { x: 1.0, y: 1.0 })
70        .add(Human)
71        .add((Eats, Apples));
72
73    println!("Bob's components:");
74    iterate_components(bob);
75
76    println!();
77
78    // We can use the same function to iterate the components of a component
79    println!("Position's components:");
80    iterate_components(world.component::<Position>().entity());
81
82    // Output:
83    //  Bob's components:
84    //  [Position, Velocity, Human, (Identifier,Name), (Eats,Apples)]
85    //
86    //  0: Position
87    //  1: Velocity
88    //  2: Human
89    //  3: (Identifier,Name)
90    //  4: (Eats,Apples)
91    //
92    //  0: entity: Position
93    //  1: entity: Velocity
94    //  2: entity: Human
95    //  3: rel: Identifier, target: Name
96    //  4: rel: Eats, target: Apples
97    //
98    //  Position's components:
99    //  [Component, (Identifier,Name), (Identifier,Symbol)
100    //
101    //  0: Component
102    //  1: (Identifier,Name)
103    //  2: (Identifier,Symbol)
104    //  3: (ChildOf,entity_iterate_components.common)
105
106    //  0: entity: Component
107    //  1: rel: Identifier, target: Name
108    //  2: rel: Identifier, target: Symbol
109    //  3: rel: ChildOf, target: common
110}
111
112#[cfg(feature = "flecs_nightly_tests")]
113#[test]
114fn test() {
115    let output_capture = OutputCapture::capture().unwrap();
116    main();
117    output_capture.test("entity_iterate_components".to_string());
118}
examples/entities/entity_iterate_components.rs

examples/entities/
entity_iterate_components.rs
