(Perl) Firebase GET - Reading Data

Demonstrates how to read parts of a Firebase JSON database. The data used in this example is at Chilkat Firebase Pigs Database, and is shown here:

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use chilkat();

# Demonstrates how to read parts of a Firebase JSON database.

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# This example assumes a JWT authentication token, if required, has been previously obtained.
# See Get Firebase Access Token from JSON Service Account Private Key for sample code.

# Load the previously obtained Firebase access token into a string.
$fac = chilkat::CkFileAccess->new();
$accessToken = $fac->readEntireTextFile("qa_data/tokens/firebaseToken.txt","utf-8");
if ($fac->get_LastMethodSuccess() != 1) {
    print $fac->lastErrorText() . "\r\n";
    exit;
}

$rest = chilkat::CkRest->new();

# Make the initial connection (without sending a request yet).
# Once connected, any number of requests may be sent.  It is not necessary to explicitly
# call Connect before each request.  
$success = $rest->Connect("chilkat.firebaseio.com",443,1,1);
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# If authentication is required...
$authGoogle = chilkat::CkAuthGoogle->new();
$authGoogle->put_AccessToken($accessToken);
$rest->SetAuthGoogle($authGoogle);

# Chilkat's sample data (pig-rescue data) is publicly readable at: https://chilkat.firebaseio.com/.json

# Let's get the animals with the shallow parameter so we can see how many pigs exist.
$jsonResponse = $rest->fullRequestNoBody("GET","/pig-rescue/animal.json?shallow=true");
if ($rest->get_LastMethodSuccess() != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# The JSON returned should look like this:  
# {"-KI3bD-FU_Dake7sYOiP":true,"-KI3bD-FU_Dake7sYOiT":true,"-KI3bD-FU_Dake7sYOiS":true,"-KI3bD-FU_Dake7sYOiU":true,"-KI3bD-FU_Dake7sYOiV":true,"-KI3bD-FU_Dake7sYOiR":true,"-KI3bD-FU_Dake7sYOiQ":true}
print $jsonResponse . "\r\n";

# Parse the response so we can iterate over each pig in the database..
$piggyPath = chilkat::CkStringBuilder->new();
$shallow = chilkat::CkJsonObject->new();
$piggyData = chilkat::CkJsonObject->new();
$shallow->Load($jsonResponse);
$count = $shallow->get_Size();
$i = 0;
while ($i < $count) {

    # Get each individual pig's data.
    $piggyPath->Clear();
    $piggyPath->Append("/pig-rescue/animal/");
    $piggyPath->Append($shallow->nameAt($i));
    $piggyPath->Append("/.json");

    $piggyJson = $rest->fullRequestNoBody("GET",$piggyPath->getAsString());
    if ($rest->get_LastMethodSuccess() != 1) {
        print $rest->lastErrorText() . "\r\n";
        exit;
    }

    # Show this piggy's data...
    # An example of one pig's data is shown here:
    # {"birth":"February, 1998","from":"Middle Ave.","gender":"F","in-date":"January, 2000",
    #   "name":"Molly II","picture":{"caption":"Molly in the Pasture","description":"Black pig","file":"molly_th.jpg"},
    #   "species":"pot belly pig","type":"Cathy's Herd"}
    print "---- " . $i . " ----" . "\r\n";
    print $piggyJson . "\r\n";

    # Let's get the pig's name, and the caption of the picture.
    $piggyData->Load($piggyJson);
    print "name: " . $piggyData->stringOf("name") . "\r\n";
    print "caption: " . $piggyData->stringOf("picture.caption") . "\r\n";

    $i = $i + 1;
}

# Note: In many of the Chilkat examples, you may notice strange ways
# of doing something that should be simpler and shorter.  For example,
# building the piggyPath (above) could've been written differently,
# with some simple string concatenation.
# 
# The reason is that the Chilkat examples are written in a 
# proprietary "example code" scripting language,
# and then automatically generated to each of the different programming
# languages you see on example-code.com.  The code generation is
# limited in what it can do.  For example, string concatentation
# is not yet a feature of the "example code" scripting language (as of May 2016), 
# and therefore you won't see the use of a programming language's string
# concatentation operators in any example.  
#