Unicode C++

Firebase GET - Reading Data

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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:

Unicode C++

#include <CkFileAccessW.h>
#include <CkRestW.h>
#include <CkAuthGoogleW.h>
#include <CkStringBuilderW.h>
#include <CkJsonObjectW.h>

void ChilkatSample(void)
    {
    bool success = false;

    // 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.
    CkFileAccessW fac;
    const wchar_t *accessToken = fac.readEntireTextFile(L"qa_data/tokens/firebaseToken.txt",L"utf-8");
    if (fac.get_LastMethodSuccess() != true) {
        wprintf(L"%s\n",fac.lastErrorText());
        return;
    }

    CkRestW rest;

    // 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(L"chilkat.firebaseio.com",443,true,true);
    if (success != true) {
        wprintf(L"%s\n",rest.lastErrorText());
        return;
    }

    // If authentication is required...
    CkAuthGoogleW authGoogle;
    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.
    const wchar_t *jsonResponse = rest.fullRequestNoBody(L"GET",L"/pig-rescue/animal.json?shallow=true");
    if (rest.get_LastMethodSuccess() != true) {
        wprintf(L"%s\n",rest.lastErrorText());
        return;
    }

    // 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}
    wprintf(L"%s\n",jsonResponse);

    // Parse the response so we can iterate over each pig in the database..
    CkStringBuilderW piggyPath;
    CkJsonObjectW shallow;
    CkJsonObjectW piggyData;
    shallow.Load(jsonResponse);
    int count = shallow.get_Size();
    int i = 0;
    while (i < count) {

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

        const wchar_t *piggyJson = rest.fullRequestNoBody(L"GET",piggyPath.getAsString());
        if (rest.get_LastMethodSuccess() != true) {
            wprintf(L"%s\n",rest.lastErrorText());
            return;
        }

        // 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"}
        wprintf(L"---- %d ----\n",i);
        wprintf(L"%s\n",piggyJson);

        // Let's get the pig's name, and the caption of the picture.
        piggyData.Load(piggyJson);
        wprintf(L"name: %s\n",piggyData.stringOf(L"name"));
        wprintf(L"caption: %s\n",piggyData.stringOf(L"picture.caption"));

        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.  
    // 
    }