(Perl) 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 Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

$json = chilkat::CkJsonObject->new();

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

$success = $json->Load($jsonStr);
if ($success != 1) {
    print $json->lastErrorText() . "\r\n";
    exit;
}

# Get the "abc" object.
# abcObj is a JsonObject
$abcObj = $json->ObjectOf("abc");
if ($json->get_LastMethodSuccess() == 0) {
    print "abc object not found." . "\r\n";
    exit;
}

# Side note: The JSON of a sub-part of the document can be emitted from any JSON object:
$abcObj->put_EmitCompact(0);
print $abcObj->emit() . "\r\n";

# Navigate to the "x" array
# xArray is a JsonArray
$xArray = $abcObj->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
# bObj is a JsonObject
$bObj = $xArray->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"
print "b2 = " . $bObj->IntOf("b2") . "\r\n";

# Now go back to the JSON doc root:
# docRoot is a JsonObject
$docRoot = $bObj->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.
$docRoot->put_EmitCompact(0);
print $docRoot->emit() . "\r\n";