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41 lines
1.1 KiB
Markdown
41 lines
1.1 KiB
Markdown
# Sources
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Sources are special objects that store a single value. They are the core of
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Vide's reactivity. They are called sources because they act as sources of data.
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A source can be created using `source()`.
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```lua
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local source = vide.source
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local count = source(0)
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```
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The value passed to `source()` is the initial value of the source.
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The value of a source can be set by calling it with an argument, and can be read
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by calling it with no arguments.
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```lua
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count(count() + 1) -- increment count by 1
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```
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Sources can be *derived* by wrapping them in functions. A wrapped source
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effectively becomes a new source.
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```lua
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local count = source(0)
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local text = function()
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return "count: " .. tostring(count())
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end
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print(text()) -- "count: 0"
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count(1)
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print(text()) -- "count: 1"
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```
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Sources on their own aren't very special, the above can be achieved with plain
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variables. The real use for sources become apparent when used in combination
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with *effects*. Similar to a signal and connection, a source and effect allows
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you to do things like automatically updating UI when a source is updated.
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