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Getting Component

To get a component from an entity, you need to call the Get method on the component field.
system/example_get_position.go
package system

import (
	"github.com/argus-labs/monorepo/pkg/cardinal"
	"github.com/argus-labs/monorepo/pkg/cardinal/examples/demo-game/component"
)

type GetPositionSystemState struct {
	cardinal.BaseSystemState
	Players PlayerSearch
}

func GetPositionSystem(state *GetPositionSystemState) error {
	for entity, player := range state.Players.Iter() {
		position := player.Position.Get()

		state.Logger().Info().
			Uint32("entity", uint32(entity.ID)).
		  Msgf("Player is at position X: %d, Y: %d", position.X, position.Y)
	}
	return nil
}
What’s PlayerSearch? Learn more in Searching for Entities with Components.

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Setting Component

To set a component on an entity, you need to call the Set method on the component field with the new component data.
system/example_set_position.go
package system

import (
	"github.com/argus-labs/monorepo/pkg/cardinal"
	"github.com/argus-labs/monorepo/pkg/cardinal/examples/demo-game/component"
)

type SetPositionSystemState struct {
	cardinal.BaseSystemState
	Players PlayerSearch
}

func SetPositionSystem(state *SetPositionSystemState) error {
	for entity, player := range state.Players.Iter() {
		player.Position.Set(component.Position{X: 100, Y: 200})

		state.Logger().Info().
			Uint32("entity", uint32(entity.ID)).
			Msg("Updated player position to X: 100, Y: 200")
	}
	return nil
}