1.3 KiB
Sources
Sources in Vide are special objects that store a single value. They are the core of reactivity in Vide. Each source represents a source of data, and they can be composed and derived to create new sources of data.
A source in Vide can be created using source().
local source = vide.source
local count = source(0)
The value passed to source() is the initial value of the source.
The value of a source can be set by calling it with an argument, and can be read by calling it with no arguments.
count(count() + 1) -- increment count by 1
Sources can be derived by wrapping them in functions. A wrapped source effectively becomes a new source.
Derived sources should be pure functions. This is where the same output is always produced for the same input no matter how many times it is reran.
local count = source(0)
local text = function()
return "count: " .. tostring(count())
end
print(text()) -- "count: 0"
count(1)
print(text()) -- "count: 1"
Sources on their own aren't very special, the above can be achieved with plain variables. The real use for sources become apparent when used in combination with Vide's reactive scopes. When a source is read from within a reactive scope, it can automatically rerun the scope that reads it when the source is updated in the future.