+- Logic Machine Forum (https://forum.logicmachine.net)
+-- Forum: LogicMachine eco-system (https://forum.logicmachine.net/forumdisplay.php?fid=1)
+--- Forum: Scripting (https://forum.logicmachine.net/forumdisplay.php?fid=8)
+--- Thread: Match nth item of a string (/showthread.php?tid=4455)
Match nth item of a string - Joep - 18.12.2022
I'm looking for a way to grab the value of the 3th parent and 2th child item of a string. Below an example of the data i get. The value i need is marked in red. It's not possible to use the id's as they change all the time. With css it's done like this item:nth-child(3) item:nth-child(2) but how is it done in Lua?
<values>
<item id='0x8764bc'>
<item id='0x87676c'>
<value>32.5°C</value>
</item>
<item id='0x87de1c'>
<value>28.6°C</value>
</item>
<item id='0x87de64'>
<value>28.4°C</value>
</item>
<item id='0x876724'>
<value>62.7°C</value>
</item>
</item>
<item id='0x876504'>
<item id='0x8b7ab4'>
<value>Aan</value>
</item>
<item id='0x87e0d4'>
<value>Aan</value>
</item>
</item>
<item id='0x8765dc'>
<item id='0x878554'>
<value>Uit</value>
</item>
<item id='0x861b84'>
<value>Aan</value>
</item>
<item id='0x861bcc'>
<value>Aan</value>
</item>
<item id='0x87850c'>
<value>Aan</value>
</item>
</item>
</values>
RE: Match nth item of a string - admin - 20.12.2022
It makes more sense to find values by ID instead of position inside of the XML that can potentially change. Try this:
Code:
data = [[
<values>
<item id='0x8764bc'>
<item id='0x87676c'>
<value>32.5°C</value>
</item>
<item id='0x87de1c'>
<value>28.6°C</value>
</item>
<item id='0x87de64'>
<value>28.4°C</value>
</item>
<item id='0x876724'>
<value>62.7°C</value>
</item>
</item>
<item id='0x876504'>
<item id='0x8b7ab4'>
<value>Aan</value>
</item>
<item id='0x87e0d4'>
<value>Aan</value>
</item>
</item>
<item id='0x8765dc'>
<item id='0x878554'>
<value>Uit</value>
</item>
<item id='0x861b84'>
<value>Aan</value>
</item>
<item id='0x861bcc'>
<value>Aan</value>
</item>
<item id='0x87850c'>
<value>Aan</value>
</item>
</item>
</values>]]
function starttag(p, tag, attrs)
if tag == 'item' then
id = attrs.id
elseif tag == 'value' then
value = true
end
end
function endtag(p, tag)
if tag == 'item' then
id = nil
elseif tag == 'value' then
value = nil
end
end
function text(p, tdata)
if value and id then
values[ id ] = tdata
value = nil
end
end
values = {}
require('lxp').new({
StartElement = starttag,
EndElement = endtag,
CharacterData = text,
}):parse(data)
log(values)RE: Match nth item of a string - Joep - 20.12.2022
With this function i got a nice result of the items with their values but as the ID's change with every new connection made i can't use them.
Also the sorting is different using this function and with the raw data it's not. Below to examples with different ID's as you can see.
* table:
["0xe9fd3c"]
* string: 3144h
["0xe9a164"]
* string: 0.01 V
["0xde6bb4"]
* string: Aan
["0xe5a494"]
* string: Verwarmen
...
* table:
["0xee5dc4"]
* string: 3144h
["0xeb74cc"]
* string: 31 Hz
["0xebf184"]
* string: 1070
["0xf1a3f4"]
* string: 17593.1 kWh
...
RE: Match nth item of a string - Joep - 20.12.2022
This one is solved by Erwin van der Zwart already. He send me this solution that create a table with sorted numbering.
function text(p, tdata)
if value and id then
table.insert(values, tdata)
value = nil
end
end