[solved] Checking persistent data with history, while the script initializes, gives an error [SOLVED]

[jake]

Checking persistent data with history, while the script initializes, gives an error. The result is that the script stops and doesn't create the __data xyz file with a fresh first data point.

This part of the script makes it stop when I try to run it for the first time. With 'history true' you can't give an initial value

Code: Select all

	local counter = domoticz.data.showerCounter
	
	if counter.getLatest().data == nil then
		counter.add(0)
		domoticz.log('ShowerCounter op 0 gezet, initial')
	end

This is a real pity, because the script can't check the value of the data, because it might be 'nil' which still causes the script to quit. On the other hand when I simply .add (0) I might overwrite an existing value every minute, while that is not wanted.

Luckily I had an other device that I could check the 'latest update' from and use that as a decision whether it was safe to put a '0' value in there. Now the __data file is created, I could use the above code again (but of course it doesn't make sense anymore).

[waaren]

can you please share the complete script ? It is kind of hard to judge what is happening based in this code snippet.

To set an initial value with history true: data = { varname = { initial = 0, history = true, maxItems = 100 } },

[dannybloe]

getLatest() returns a data table or nil if there is no data. Your check is not correct:

Code: Select all

local latest = counter.getLatest()
if (latest == nil) then
    ...

You can also check the size:

Code: Select all

if (counter.size == 0) then
   ...

[jake]

can you please share the complete script ? It is kind of hard to judge what is happening based in this code snippet.

To set an initial value with history true: data = { varname = { initial = 0, history = true, maxItems = 100 } },

getLatest() returns a data table or nil if there is no data. Your check is not correct:

Code: Select all

local latest = counter.getLatest()
if (latest == nil) then
    ...

You can also check the size:

Code: Select all

if (counter.size == 0) then
   ...

Thanks to both of you. I'm sorry that I forgot to add the initialisation of the script, where I define the 'persistent data'. I was not aware that I could add the 'initial = var2' to this type of data as well. I have added this to the example in the wiki.

I also saw that I used the wrong check in the IF statement. I fixed that now as well, just as a double check to prevent an error if the data file would become corrupt.