CONTROL
- Introduction to CTRL
  An introduction to the product's own programming language Control(CTRL).
- CONTROL Classes
- Types of Control Functions
  An overview of the types of functions distinguished within Control.
- Control graphics
- CONTROL Functions
  - Functions A
  - Functions B
  - Functions C
  - Functions D
  - Functions E
  - Functions F
  - Functions G
  - Functions H
  - Functions I
  - Functions J
    - jsonDecode()
      The function jsonDecode() decodes a JSON encoded string variable.
    - jsonEncode()
      The function encodes data into an JSON format string.
    - jwtDecode()
      The function decodes a JSON Web Token (JWT).
    - jwtEncode()
      Returns an encoded JSON Web Token (JWT).
  - Functions K
  - Functions L
  - Functions M
  - Functions N
  - Functions O
  - Functions P
  - Functions Q
  - Functions R
  - Functions S
  - Functions T
  - Functions U
  - Functions V
  - Functions W
  - Functions X
  - Functions Y
  - Functions Z
- CTRL Debugger
  With the CTRL Debugger you can debug the programming language Control.
- CtrlExtension
  The CtrlExtension allows the addition of custom C++ code.
- CTRLPPCheck
  Save time and money with increased code quality in your projects

jsonDecode()

The function jsonDecode() decodes a JSON encoded string variable.

Synopsis

<any type> jsonDecode(string json);

Parameters


Parameter	Description
json	The string that is decoded. The variable was encoded by using the function jsonEncode(). Note: The Byte-Order-Mark (BOM) is not processed but causes an error if it is contained in a string. See also the encoding parameters of the function fileToString().

Return Value

Decoded value

Description

JSON is a data exchange format and uses human-readable text for transmitting data objects. JSON builds two structures:

Name/value pairs. In different languages this is implemented as an object (object), a set (record), a structure (struct), a dictionary or a directory (dictionary), a hash table (hash table), a key list (keyed list) or as an associative array (associative array).
An ordered list of values. In most languages it is implemented as an array, a vector or a list.

It is largely used instead of XML. Furthermore, it is used for asynchronous browser/server communication (AJAX).

The JSON text format is independent of programming languages and is therefore ideally suited for data exchange.

Tip:

To detect decoding errors, use the function getLastError().

Note:

Since JSON only understands numeric and string data types, most of the WinCC OAdata types are converted to strings.

There are, however some exceptions:

atime -> object with elements:time, count, dpid
errClass -> object with elements: prio, type, id, text
langString -> object with one element per language
nullptr -> object with the JSON value of null

Note:

A data type of time is always encoded in ISO-8601 format in UTC timezone, according to:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toJSON

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString

Assignment

Misc. functions

Availability

UI, CTRL