(Visual FoxPro) Get the Root of a JSON Document

Demonstrates how to get back to the JSON root object from anywhere in the JSON document. This example uses the following JSON document:

{
  "flower": "tulip",
  "abc":
    {
    "x": [
       { "a" : 1 },
       { "b1" : 100, "b2" : 200 },
       { "c" : 3 }
    ],
    "y": 200,
    "z": 200
    }
}

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loJson
LOCAL lcJsonStr
LOCAL lnSuccess
LOCAL loAbcObj
LOCAL loXArray
LOCAL loBObj
LOCAL loDocRoot

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')

lcJsonStr = '{"flower": "tulip","abc":{"x": [{ "a" : 1 },{ "b1" : 100, "b2" : 200 },{ "c" : 3 }],"y": 200,"z": 200}}'

lnSuccess = loJson.Load(lcJsonStr)
IF (lnSuccess <> 1) THEN
    ? loJson.LastErrorText
    RELEASE loJson
    CANCEL
ENDIF

* Get the "abc" object.
loAbcObj = loJson.ObjectOf("abc")
IF (loJson.LastMethodSuccess = 0) THEN
    ? "abc object not found."
    RELEASE loJson
    CANCEL
ENDIF

* Side note: The JSON of a sub-part of the document can be emitted from any JSON object:
loAbcObj.EmitCompact = 0
? loAbcObj.Emit()

* Navigate to the "x" array
loXArray = loAbcObj.ArrayOf("x")
* We'll skip the null check and assume it's non-null...

* Navigate to the 2nd object contained within the array.  This contains members b1 and b2
loBObj = loXArray.ObjectAt(1)
* We'll skip the null check and assume it's non-null...

* Show that we're at "b1/b2".
* The value of "b1" should be "200"
? "b2 = " + STR(loBObj.IntOf("b2"))

* Now go back to the JSON doc root:
loDocRoot = loBObj.GetDocRoot()
* We'll skip the null check and assume it's non-null...

* Pretty-print the JSON doc from the root to show that this is indeed the root.
loDocRoot.EmitCompact = 0
? loDocRoot.Emit()

RELEASE loDocRoot
RELEASE loBObj
RELEASE loXArray
RELEASE loAbcObj

RELEASE loJson