JSON (WString format) accessing elements. Convert to STRUCT?

2025-10-09T08:51:49.324000Z

HI , Ill try the same with Energy prices. But no data I add the Query to the wsPost. Add $ because wstring use "as start end end. Here the link of the API info
https://reversed.notion.site/Marktprijzen-API-89ce600a88ac4abe8c2ad89d3167a83e

JSON (WString format) accessing elements. Convert to STRUCT?

2025-10-09T08:51:44.974000Z

JSON (WString format) accessing elements. Convert to STRUCT?

2023-05-23T12:30:04.906000Z

There's not actually any code in the JSONVAR function block itself, all the work is done in properties and methods. If you post an example I can test it.

JSON (WString format) accessing elements. Convert to STRUCT?

2023-05-21T08:13:16.262000Z

Hello, can you share the code from the funcional block jsonvar. when I go to it is empty, only I can see the vars.
Actually I followed all conversation and at my site it doesnt work

JSON (WString format) accessing elements. Convert to STRUCT?

2023-03-31T01:49:04.052000Z

Thanks, TVM! I used the xReceived output from the Subscribe function block to trigger the ParsJSON function and it worked!

JSON (WString format) accessing elements. Convert to STRUCT?

2023-03-30T21:46:41.243000Z

That makes sense. I will do some testing and update you here. Thanks for pointing me in the right direction.

JSON (WString format) accessing elements. Convert to STRUCT?

2023-03-30T21:26:51.352000Z

I just tried your here and it works for me. ParseJSON is looking for the rising edge of Execute, are you sure your sPayload variable has data in it before the parse is executed?

JSON (WString format) accessing elements. Convert to STRUCT?

2023-03-30T02:24:53.590000Z

Thanks for creating this library. I have followed your directions and the parse json example is not working me. I found this thread as it is a similar application to mine. I am receiving a String Value from an MQTT subscribe function block. The issue is that I am getting null values.

Below is my struct:

TYPE FanRefSpeedJson :
STRUCT
    timestamp       : JSONVAR;
    value           : JSONVAR;
END_STRUCT
END_TYPE

Below are the relevant variables:

VAR
    sPayload                : STRING;
    FanRefSpeedJSON_1       : FanRefSpeedJson;
    ParseJSON               : JSON_TO_STRUCT;
END_VAR

Below is the return value from the MQTT Subscribe Function Block (sPayload)

'{"timestamp":1680099744985,"value":30}'

Below is the ParseJSON code:

ParseJSON(
    Execute:= TRUE,
    JSONString:= ADR(sPayload), 
    JSONStringSize:= SIZEOF(sPayload),
    JSONVars:= ADR(FanRefSpeedJSON_1),
    NumberOfVars:= SIZEOF(FanRefSpeedJSON_1) / SIZEOF(JSONVAR)
);

Attached are some screenshots showing the code and null values.

JSON (WString format) accessing elements. Convert to STRUCT?

2021-11-17T15:34:36.696000Z

Here's an example of one of the structures I was using with Open Weather Map:

TYPE OWM_WEATHER :
STRUCT
    id:             JSONVAR;
    main:           JSONVAR;
    description:    JSONVAR;
    icon:           JSONVAR;
END_STRUCT
END_TYPE

Weather:    OWM_WEATHER;

You'll have to create structures and arrays that match the expected result from whichever API you're using. Order doesn't matter, but the structure does. (But parsing will be faster if the order matches as closely as possible).

So then, for example, if I want to get the description, I could access Weather.description.CharString
or if I wanted the id, I'd use Weather.id.Integer, (or Weather.id.Number if I wanted it as a floating point value)

take a look at the documentation in the JSONVAR function block, basically it guesses at the type when parsing from the string (because it uses the setter of the .AsString property), but you can then access it as whatever type you need (string, boolean, integer, number, or datetime)

JSON (WString format) accessing elements. Convert to STRUCT?

2021-11-17T14:45:17.144000Z

Ok so looking at "ParseJSON"...feed it in a String, then how do I access members of an Element, then an object in an Array, i.e. how does it determine which Type?

"coord" : {

"lon" : -82.4584,
"lat" : 27.9475

},
"weather" : [

{
"id" : 804,
"main" : Clouds,
"description" : overcast clouds,
"icon" : 04d
}

?- What would be the syntax to assign the element to a temp variable, for example
temp := JSONVars.weather.main

Appreciate any input, gonna have to do my due diligence on the coding aspects for sure.

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