Limedev: Removed unnecessary padding.

2024-02-14T12:56:18Z

Removed unnecessary padding.

← Older revision		Revision as of 12:56, 14 February 2024
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			__NOTOC__
	{{Useful Class}}		{{Useful Class}}
	~~__NOTOC__~~
	This class allows you to watch for variables changes.		This class allows you to watch for variables changes.

CrosRoad95: Created page with "{{Useful Class}} NOTOC This class allows you to watch for variables changes. Call observable variable to push new state. Author: CrosRoad95 Contact discord: mtasa.com/di..."

2020-09-21T15:42:32Z

Created page with "{{Useful Class}} __NOTOC__ This class allows you to watch for variables changes. Call observable variable to push new state. Author: CrosRoad95 Contact discord: mtasa.com/di..."

New page

{{Useful Class}}
__NOTOC__
This class allows you to watch for variables changes.

Call observable variable to push new state.

Author: CrosRoad95
Contact discord: mtasa.com/discord
==Requirements==

OOP turn on

==Code==
<syntaxhighlight lang="lua">
observable = {}

function observable:onChange(callback)
self.callback = callback
end

function observable:__tostring()
return self.value
end

function observable:__call(newState)
if(self.value == newState)then
return false
end
local oldValue = self.value;
self.value = newState;
if(self.callback)then
self.callback(oldValue, self.value)
end
return true;
end

function observable:create(defaultValue)
local t = { value = defaultValue, observators = {} }
setmetatable(t, self)
self.__index = self
return t
end

function watch(callback, ...)
for i,v in ipairs({...})do
v:onChange(function(old, new)
if(callback)then
callback(i, old, new)
end
end)
end
end
</syntaxhighlight>

==Example 1==
How it works
<syntaxhighlight lang="lua">
a = observable:create("asdf") -- "asdf" is a default value.
b = observable:create(10)

watch(function(index, prvValue, newValue) -- called every time observable value has change.
print("index",index, "change", prvValue, "=> ",newValue)
end, a, b) -- pass variables you want to watch

a(20) -- index 1 change asdf => 20
b(30) -- index 2 change 10 => 30
a("aaa") -- index 1 change 20 => aaa

print("value:", a) -- in this case it will print "aaa"
</syntaxhighlight>

==See Also==
{{Useful_Classes}}

Observable - Revision history

Limedev: Removed unnecessary padding.

CrosRoad95: Created page with "{{Useful Class}} __NOTOC__ This class allows you to watch for variables changes. Call observable variable to push new state. Author: CrosRoad95 Contact discord: mtasa.com/di..."

CrosRoad95: Created page with "{{Useful Class}} NOTOC This class allows you to watch for variables changes. Call observable variable to push new state. Author: CrosRoad95 Contact discord: mtasa.com/di..."