How jtable replace hardcoded value into a variable

[RonS 0]

Simple statement where I update the led temperature of a lightbulb.

 

The first works like a charm.

jtable = '{"properties":{"parameters":[{"id":81,"size":2,"value":4999}]}}'

HC2:PUT("/api/devices/240",jtable);

 

 

[DEBUG] 13:28:04: {"properties":{"parameters":[{"id":81,"size":2,"value":4999}]}}
 

 

Now I want to have the value 2700 in a variable so I can dynamically update the bulb.

jtable = '{"properties":{"parameters":[{"id":81,"size":2,"value":TempKelvin}]}}' or

jtable = '{"properties":{"parameters":[{"id":81,"size":2,"value": ".. TempKelvin .."}]}}'

 

 

[DEBUG] 13:29:02: {"properties":{"parameters":[{"id":81,"size":2,"value":TempKelvin}]}}

[DEBUG] 13:30:45: {"properties":{"parameters":[{"id":81,"size":2,"value":".. TempKelvin .."}]}}
 

and whatever I have tried it does not replace the variable with its value.

Any suggestions?

Ron

 

 

[cag014 731]

Yes, just work with pure jSon table array and then encode it.

 

jtable={

  properties={

                        {id=81,size=2,value=TempKelvin}

                        }

         }

now

HC2:PUT("/api/devices/240",json.encode(jtable));

Much easier to understand and deal with that and not trying to convert jSon table to string manually.

Edited February 22, 2020 by cag014

[RonS 0]

Thanks @cag014. This idea works. 

 

[DEBUG] 11:19:47: Temp:3919
[DEBUG] 11:19:47: {"properties":[{"id":81,"value":3919,"size":2}]}
 

However, the order of size and value has been swapped. Can you enforce a specific order?

Ron

[cag014 731]

24 minutes ago, RonS said:

Thanks @cag014. This idea works. 

 

[DEBUG] 11:19:47: Temp:3919
[DEBUG] 11:19:47: {"properties":[{"id":81,"value":3919,"size":2}]}
 

However, the order of size and value has been swapped. Can you enforce a specific order?

Ron

Not by default.

json.encode(), pairs() functions return values in the table, in an arbitrary order, but it doesn't have any impact on functionality.

(Some extra code could be applied to keep the order.)

 

Edited February 22, 2020 by cag014

[jgab 2,642]

22 hours ago, RonS said:

Simple statement where I update the led temperature of a lightbulb.

and whatever I have tried it does not replace the variable with its value.

Any suggestions?

Ron

 

So, I would recommend @cag014 advise to create a Lua table - and the order of the elements in the json representation doesn't matter for the code accepting the structure - it could affect the readability though.

 

The reason your two first attempts failed is problem with how you construct the json string

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This doesn't replace the TempKelvin variable as it is inside the string - and the json expression is malformed so the API called probably just rejects the call.

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This has the same issue, everything is between the outer single quotes ' .... ' (see how the whole string is green according the the Lua style formatter in the post?)

This works:

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See how TempKelvin is black according the the Lua style formatter in the post.

 

If you absolutely want to create a json string with a specific order, you have to write your own json.encoder  

The reason why one would want to enforce the key order in a json string (a stable order) is when you write out Lua tables with json.encode for debugging, and you want them to look the same so you don't have to search the printout for the fields that could appear randomly...

In my own code I deal with "sourceTriggers" a lot, tables with a 'type' field and a 'deviceID' field that I want to have first in all json.encoded strings.

Looks like this

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The other advantage is that it is a bit more forgiving than the the regular json.encoder - The drawback is that it may not cater for all esoteric encoding formats...

[RonS 0]

@cag014 @jgab Thanks a lot for your contributions. Indeed the order does not prevent the execution but I was just curious and indeed in some cases it does matter. Also thanks for the explanation. Now it does make sense and will help along the way. Ron.

[RobS 3]

I have maybe the same issue here.

in the HC2 i have a coolcam sirene alarm.

in a VD i had the possibility to change sound, volume etc.

now i like to do that in my HC3 with an QA.

in the HC2 the code is:

 

local selfId = fibaro:getSelfId();
local port = fibaro:get(selfId, 'TCPPort');

HC2 = Net.FHttp("127.0.0.1", 11111)

jtable = '{"properties":{"parameters":[{"id":2,"size":1,"value":3}]}}'
HC2:PUT("/api/devices/" ..port ,jtable)

 

 when i put this in an QA in HC3 i got the message 

[ERROR] [QUICKAPP256]: QuickApp crashed

[ERROR] [QUICKAPP256]: Unknown error occurred: handleJsonRpc

can anyone help me so i understand this problem.

 

thanks

 

Edited April 13, 2020 by RobS