PureBasic

Check if Integer Exists at JSON Path

Demonstrates how to get an integer value at a JSON path, and how to check to see if it exists. PureBasic

IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

    success.i = 0

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; First build simple JSON..
    CkJsonObject::ckUpdateInt(json,"test.abc",100)

    CkJsonObject::setCkEmitCompact(json, 0)
    Debug CkJsonObject::ckEmit(json)

    ; This is our JSON:
    ; {
    ;   "test": {
    ;     "abc": 100,
    ;   }
    ; }

    path.s = "test.notHere"

    ; The call to IntOf will return 0, because it's not present.
    ; But how do we know if it really was present, and the value was truly 0?
    val.i = CkJsonObject::ckIntOf(json,path)
    Debug "val = " + Str(val)

    ; We cannot use LastMethodSuccess because LastMethodSuccess only applies
    ; to methods that:
    ; - return a string
    ; - return a new Chilkat object, binary bytes, or a date/time.
    ; - returns a boolean status where 1 = success and 0 = failed.
    ; - returns an integer where failure is defined by a return value less than zero.
    ; The IntOf method fits none of these requirements, and therefore the LastMethodSuccess 
    ; is not a valid indicator..
    wasFound.i = CkJsonObject::ckLastMethodSuccess(json)
    Debug "wasFound = " + Str(wasFound) + " (not a valid indicator)"

    ; Instead, if the returned value is 0, we can double-check to see if the member was truly there..
    If val = 0
        wasFound = CkJsonObject::ckHasMember(json,path)
        Debug "wasFound = " + Str(wasFound)
        If wasFound = 1
            Debug "The value was present and is 0."
        Else
            Debug "no member is present at test.notHere"
        EndIf

    Else
        Debug "val = " + Str(val)
    EndIf

    ; Alternatively, you could check to see if the member exists beforehand..
    If CkJsonObject::ckHasMember(json,path) = 1
        Debug "val = " + Str(CkJsonObject::ckIntOf(json,path))
    Else
        Debug "no member at " + path
    EndIf



    CkJsonObject::ckDispose(json)


    ProcedureReturn
EndProcedure