# Changelog
## v0.9.0 (2024-03-30)
### Breaking
- removes `Ecspanse.Resource.State` in favor of `Ecspanse.State` functionality.
#### Replacing the old `Ecspanse.Resource.State` with `Ecspanse.State`
##### Creating a new state
```elixir
defmodule Demo.States.Game do
use Ecspanse.State, states: [:play, :paused], default: :play
end
```
Multiple states can be defined in the same way:
```elixir
defmodule Demo.States.Area do
use Ecspanse.State, states: [:dungeon, :market, :forrest], default: :forrest
end
```
##### Conditionally running systems
Old code:
```elixir
Ecspanse.add_system(
ecspanse_data,
Demo.Systems.MoveHero,
run_in_state: [:play]
)
```
New code:
```elixir
Ecspanse.add_system(
ecspanse_data,
Demo.Systems.MoveHero,
run_in_state: {Demo.States.Game, :play}
)
```
##### Getting and setting states
Old code:
```elixir
{:ok, %Ecspanse.Resource.State{value: state}} = Ecspanse.Query.fetch_resource(Ecspanse.Resource.State)
Ecspanse.Command.update_resource!(Ecspanse.Resource.State, value: :paused)
```
New code:
```elixir
:play == Demo.States.Game.get_state!()
# Attention! The system running this command must be synchronous.
:ok = Demo.States.Game.set_state!(:paused)
```
##### Listening to state changes
```elixir
defmodule Demo.Systems.OnGamePaused do
use Ecspanse.System, event_subscriptions: [Ecspanse.Event.StateTransition]
def run(%Ecspanse.Event.StateTransition{module: Demo.States.Game, previous_state: _, current_state: :paused}) do
# logic
end
def run(_event), do: :ok
end
```
### Features
- allows inserting resources at startup with `Ecspanse.insert_resource/2`
- allows state init at startup with `Ecspanse.init_state/2`
- introduces `Ecspanse.State` state functionalities. See the breaking changes for more details.
- new library built-in `Ecspanse.Event.StateTransition` event
- new library built-in `Ecspanse.Component.Name` component
### Improvements
- `Ecspanse.Query.entity_exists?/1` to check if an entity still exists
- `Ecspanse.Command.add_and_fetch_component!/2` wrapper to return a component after creation
- `Ecspanse.Command.update_and_fetch_component!/2` wrapper to return a component after update
## v0.8.1 (2023-12-22)
### Improvements
- returns an explicit error message when trying to run queries or create events and the Ecspanse server is not running.
- documentation improvements.
## v0.8.0 (2023-11-14)
### Improvements
- refactor the `Ecspanse.Projection` to include the state of the projection
- the projection result is now wraped in a `Ecspanse.Projection{}` struct, together with the projection state.
- the `c:Ecspanse.Projection.project/1` callback returns now the projection state as well as the projection result.
### Breaking
- the `Projection.run?/2` callback has been removed. The functionality is now handled by the `c:Ecspanse.Projection.project/1` callback, by returning `:halt`.
- the `c:Ecspanse.Projection.project/1` callback should now return also the state of the projection. See the documentation for more details.
- the `c:Ecspanse.Projection.on_change/3` callback takes as second and third argument the `t:Ecspanse.Projection.t/0`.
- the `c:Ecspanse.Projection.get!/1` callback now returns a `t:Ecspanse.Projection.t/0`.
## v0.7.3 (2023-11-13)
### Improvements
- implement the `Projection.run?/2` optional callback to run projections conditionally.
## v0.7.2 (2023-11-05)
### Improvements
- `c:Ecspanse.Projection.on_change/3` is called on Projection server initialization.
## v0.7.1 (2023-10-07)
### Improvements
- `Ecspanse.Command.clone_entity!/2` and `Ecspanse.Command.deep_clone_entity!/2` now accept an `:id` option to set the id of the cloned entity.
## v0.7.0 (2023-10-05)
### Breaking
- `c:Ecspanse.Projection.on_change/3` replaces the `on_change/2` and now takes both the new projection as well as the previous projection as arguments.
### Improvements
- updating projections after all frame systems have run to return a consistent state.
## v0.6.0 (2023-10-02)
### Features
- introduces `Ecspanse.Projection` to build state projections across entities and components.
## v0.5.0 (2023-09-28)
### Features
- introduces ancestors queries to query for parents of an entity, the parents of parents, and so on:
- `Ecspanse.Query.select/2` new option: `:for_ancestors_of`
- `Ecspanse.Query.list_ancestors/1`
- `Ecspanse.Query.list_tagged_components_for_ancestors/2`
## v0.4.0 (2023-09-17)
### Breaking
- removes the automatically generated events: `Ecspanse.Event.{ComponentCreated, ComponentUpdated, ComponentDeleted, ResourceCreated, ResourceUpdated, ResourceDeleted}`. Use custom emitted events or short-lived components instead.
### Improvements
- improves performance for tagged components. The system loop now runs faster when dealing with tagged components.
## v0.3.1 (2023-08-30)
### Fixes
- fixes a bug where events could be scheduled after they were batched for the current frame, and before the current events are cleared. Causing some events to be lost. Thanks to [@andzdroid](https://github.com/andzdroid) for identifying and documenting the issue.
- fixes a bug where temporary timers would crash. Thanks to [@holykol](https://github.com/holykol) for finding and fixing the issue.
### Features
- imports `Ecspanse.Query` and `Ecspanse.Command` in all systems, so all the queries and commands are available without needing the respective module prefix.
- imports `Ecspanse` in the setup module that `use Ecspanse` so the system scheduling functions are available without needing the module prefix.
## v0.3.0 (2023-08-21)
### Features
- adds a new query `Ecspanse.Query.list_tags/1` to list a component's tags.
- adds a new query `Ecspanse.Query.list_components/1` to list all components of an entity.
- adds a new command `Ecspanse.Command.clone_entity!/1` to clone an entity without its relationships.
- adds a new command `Ecspanse.Command.deep_clone_entity!/1` to clone an entity with its descendants.
## v0.2.1 (2023-08-20)
### Fixes
- batch all events only by `batch_key` to avoid race conditions for different events processed by the same system.
## v0.2.0 (2023-08-18)
### Breaking
- `use Ecspanse.Component.Timer` and `use Ecspanse.Event.Timer` are now deprecated.
Use `use Ecspanse.Template.Component.Timer` and `use Ecspanse.Template.Event.Timer` instead.
### Features
- introduces `Ecspanse.Template.Component` and `Ecspanse.Template.Event` to simplify the creation of related components and events.
- adds a new query `Ecspanse.Query.fetch_component/2` to fetch a system's component by a list of tags.
## v0.1.2 (2023-08-14)
### Fixes
- removes unneeded dependency `plug_crypto`
- upgrades dependencies: `credo`, `ex_doc`, `jason`
## v0.1.1 (2023-08-12)
### Fixes
- adds the missing project `:package`
