How to handle nil value from http request

[mortesan 9]

I am setting up some controls for my chromecast audios with a webserver on a raspberry Pi, I am fetching the values like volume and whats playing, but when there's nothing playing on the chromecast I get a nil value and the scene stops, how can I handle these nil values? 

 

could I use something like if ~ = nil ?

 

 

 

local http = net. HTTPClient () 
http : request ( "http://xxx/getDeviceStatus?address=xxx",  {
    options =  {
        method =  "PUT",
        },
    success = function(status)
       

       response = status.data        
    svar = json.decode(response)

      --printer verdier
       
      print ("Volum: "..svar.status.volume.level);
      print ("Muted: "..tostring(svar.status.volume.muted));
      print ("Spiller fra: "..tostring(svar.status.applications[1].displayName));
      print ("Media: "..tostring(svar.status.applications[1].statusText));
      print ("sessioId: "..tostring(svar.status.applications[1].sessionId));

     fibaro:setGlobal('volumbad',svar.status.volume.level); 
     fibaro:setGlobal('spillerbad',tostring(svar.status.applications[1].displayName));
     fibaro:setGlobal('idbad',svar.status.applications[1].sessionId);
      
      end
    
   })

 

 

Debug: 

 

 

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[Alex 32]

Yes, I think so.

if (svar.status ~=nil) then ... end

[AutoFrank 372]

@mortesan

 

You could check just after the response read for a part of the json that you would expect to be there

 

Here is a an example I use..

 

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for the else you could use 

return - if its part of a function  or fibaro:abort() - which will stop that iteration of the main loop/button..

 

 

[mortesan 9]

Thank you for some good advise, got it working with if == nil then ..  else ...

 

if svar.status.applications == nil then
        print ("Volum bad: "..svar.status.volume.level);
        print ("Muted bad: "..tostring(svar.status.volume.muted));
        fibaro:setGlobal('volumbad',svar.status.volume.level);
        fibaro:setGlobal('spillerbad',"Nothing is playing");
        
        else 
        print ("Volum bad: "..svar.status.volume.level);
         print ("Muted bad: "..tostring(svar.status.volume.muted));
        print ("Spiller fra: "..tostring(svar.status.applications[1].displayName));
        print ("Media: "..tostring(svar.status.applications[1].statusText));
        print ("sessioId: "..tostring(svar.status.applications[1].sessionId));
        fibaro:setGlobal('volumbad',svar.status.volume.level);
        fibaro:setGlobal('spillerbad',tostring(svar.status.applications[1].displayName));
        fibaro:setGlobal('idbad',svar.status.applications[1].sessionId);
        
      end;

 

 

 

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Edited July 30, 2017 by mortesan

[AutoFrank 372]

@mortesan

Glad you got it working

 

 

_af