Domoticz

Bumke1963 wrote: ↑Wednesday 10 June 2020 19:52 Can someone explain when to use a local function and when a 'normal/non-local' function ?
And maybe you are the right person also who can explain a local variable and how to use a global variable ?

waaren wrote: ↑Wednesday 10 June 2020 20:42

Bumke1963 wrote: ↑Wednesday 10 June 2020 19:52 Can someone explain when to use a local function and when a 'normal/non-local' function ?
And maybe you are the right person also who can explain a local variable and how to use a global variable ?

There are books written about this question and these are freely available on the internet. If you don't have time to study these, the rule of thumb is to use local everywhere for functions and variables where possible. It limits the scope of them (less hard to find bugs) and in Lua it has also significant performance advantages. ^ref

Bumke1963 wrote: ↑Wednesday 10 June 2020 20:51 I google'd a lot on this subject, didn't find one LUA example in combination with Domoticz which explains the difference.
Someone has a better idea or a link to an example ?

local function outer()

	function inner() -- This function can be used in this script below this line
		return('inner')
	end

	return 'outer-' .. inner()
end

print('Calling outer() ==>> ' .. outer()  )                -->> prints: Calling outer() ==>> outer-inner
print ('Calling inner() ==>> ' .. tostring(inner() ))      -->>  prints: Calling inner() ==>> inner  




local function outerL()

	local function innerL() -- This function can only be used within the scope of  outerL
		return('innerL')
	end

	return 'outerL-' .. innerL()
end

print('Calling outerL() ==>> ' .. outerL()  )              -->>  prints: Calling outerL() ==>> outerL-innerL
print ('Calling innerL() ==>> ' .. tostring(innerL() ))    -->> error: attempt to call a nil value (global 'innerL')

Bumke1963 wrote: ↑Sunday 14 June 2020 13:00 Thnx, i am a newbie but i am getting it bit for bit. Now the question remains: where do i declare my own global variables in Domoticz-LUA. I know Lua nows time, device, etc. events. So where to put them ?