mirror of
https://github.com/centau/vide.git
synced 2026-08-20 14:41:37 +00:00
125 lines
2.2 KiB
Markdown
125 lines
2.2 KiB
Markdown
# Reactivity API: Core
|
|
|
|
<br/>
|
|
|
|
:::warning
|
|
Yielding is not allowed in any stable or reactive scope. Strict mode will check
|
|
for this.
|
|
:::
|
|
|
|
## root()
|
|
|
|
Creates and runs a function in a new stable scope.
|
|
|
|
- **Type**
|
|
|
|
```lua
|
|
function root<T...>(fn: (destroy: () -> ()) -> T...): T...
|
|
```
|
|
|
|
- **Details**
|
|
|
|
Returns the result of the given function.
|
|
|
|
Creates a new stable scope, where creation of effects can be tracked and
|
|
properly disposed of.
|
|
|
|
A function to destroy the root is passed into the callback, which will run
|
|
any cleanups and allow derived sources created to garbage collect.
|
|
|
|
## source()
|
|
|
|
Creates a new source with the given value.
|
|
|
|
- **Type**
|
|
|
|
```lua
|
|
function source<T>(value: T): Source<T>
|
|
|
|
type Source<T> =
|
|
() -> T -- get
|
|
& (T) -> () -- set
|
|
```
|
|
|
|
- **Details**
|
|
|
|
Calling the returned source with no argument will return its stored value,
|
|
calling with an argument will set a new value.
|
|
|
|
- **Example**
|
|
|
|
```lua
|
|
local count = source(0)
|
|
|
|
count() -- 0
|
|
|
|
count(count() + 1) -- 1
|
|
```
|
|
|
|
## effect()
|
|
|
|
Runs a side-effect in a new reactive scope on source update.
|
|
|
|
- **Type**
|
|
|
|
```lua
|
|
function effect(callback: () -> ())
|
|
```
|
|
|
|
- **Details**
|
|
|
|
Any time a source referenced in the callback is updated, the callback will
|
|
be reran.
|
|
|
|
The callback is ran once immediately.
|
|
|
|
- **Example**
|
|
|
|
```lua
|
|
local num = source(1)
|
|
|
|
effect(function()
|
|
print(num())
|
|
end)
|
|
|
|
-- prints 1
|
|
|
|
num(num() + 1)
|
|
|
|
-- prints 2
|
|
```
|
|
|
|
## derive()
|
|
|
|
Derives a new source in a new reactive scope from existing sources.
|
|
|
|
- **Type**
|
|
|
|
```lua
|
|
function derive<T>(source: () -> T): () -> T
|
|
```
|
|
|
|
- **Details**
|
|
|
|
The derived source will have its value recalculated when any source source
|
|
it derives from is updated.
|
|
|
|
Anytime its value is recalculated it is also cached, subsequent calls will
|
|
retun this cached value until it recalculates again.
|
|
|
|
The callback is ran once immediately.
|
|
|
|
- **Example**
|
|
|
|
```lua
|
|
local count = source(0)
|
|
local text = derive(function() return `count: {count()}` end)
|
|
|
|
text() -- "count: 0"
|
|
|
|
count(1)
|
|
|
|
text() -- "count: 1"
|
|
```
|
|
|
|
--------------------------------------------------------------------------------
|