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Unicode C

Dropbox Refresh OAuth2 Access Token

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Demonstrates how to mint a new access token using the refresh token obtained when originally getting the OAuth2 access token.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkHttpW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkHttpRequestW.h>
#include <C_CkHttpResponseW.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttpW http;
    HCkJsonObjectW json;
    HCkHttpRequestW req;
    HCkHttpResponseW resp;
    HCkStringBuilderW sbResponseBody;
    HCkJsonObjectW jResp;
    int respStatusCode;
    const wchar_t *access_token;

    success = FALSE;

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

    http = CkHttpW_Create();

    // Implements the following CURL command:

    // curl -X GET https://api.dropbox.com/oauth2/token \
    //     -d grant_type=refresh_token \
    //     -d refresh_token=<YOUR_REFRESH_TOKEN> \
    //     -u <YOUR_APP_KEY>:<YOUR_APP_SECRET>

    // Use the following online tool to generate HTTP code from a CURL command
    // Convert a cURL Command to HTTP Source Code

    CkHttpW_putLogin(http,L"DROPBOX_APP_KEY");
    CkHttpW_putPassword(http,L"DROPBOX_APP_SECRET");

    // Get the refresh token from the JSON we saved when originally getting the access token.
    // (See Get Dropbox OAuth2 Access Token w/ Refresh Token
    json = CkJsonObjectW_Create();
    success = CkJsonObjectW_LoadFile(json,L"qa_data/tokens/dropbox.json");
    if (success == FALSE) {
        wprintf(L"%s\n",CkJsonObjectW_lastErrorText(json));
        CkHttpW_Dispose(http);
        CkJsonObjectW_Dispose(json);
        return;
    }

    req = CkHttpRequestW_Create();
    CkHttpRequestW_AddParam(req,L"grant_type",L"refresh_token");
    CkHttpRequestW_AddParam(req,L"refresh_token",CkJsonObjectW_stringOf(json,L"refresh_token"));

    CkHttpRequestW_putHttpVerb(req,L"POST");
    CkHttpRequestW_putContentType(req,L"application/x-www-form-urlencoded");

    resp = CkHttpResponseW_Create();
    success = CkHttpW_HttpReq(http,L"https://api.dropbox.com/oauth2/token",req,resp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkHttpW_Dispose(http);
        CkJsonObjectW_Dispose(json);
        CkHttpRequestW_Dispose(req);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    sbResponseBody = CkStringBuilderW_Create();
    CkHttpResponseW_GetBodySb(resp,sbResponseBody);

    jResp = CkJsonObjectW_Create();
    CkJsonObjectW_LoadSb(jResp,sbResponseBody);
    CkJsonObjectW_putEmitCompact(jResp,FALSE);

    wprintf(L"Response Body:\n");
    wprintf(L"%s\n",CkJsonObjectW_emit(jResp));

    respStatusCode = CkHttpResponseW_getStatusCode(resp);
    wprintf(L"Response Status Code = %d\n",respStatusCode);
    if (respStatusCode >= 400) {
        wprintf(L"Response Header:\n");
        wprintf(L"%s\n",CkHttpResponseW_header(resp));
        wprintf(L"Failed.\n");
        CkHttpW_Dispose(http);
        CkJsonObjectW_Dispose(json);
        CkHttpRequestW_Dispose(req);
        CkHttpResponseW_Dispose(resp);
        CkStringBuilderW_Dispose(sbResponseBody);
        CkJsonObjectW_Dispose(jResp);
        return;
    }

    // Sample JSON response:
    // (Sample code for parsing the JSON response is shown below)

    // {
    //   "access_token": "sl.AC75WPYRqOi0mxcRqlimbV9FKHu04biz5qHwatG3MTgzFK7kLrGVlM9EgP4603tE7bWw0s1rMbTKiHsf37TUshPYvq-3r0qeBr_PrZIAibN8XOQicvboiOnqx6JrDekq-w8D-tE",
    //   "token_type": "bearer",
    //   "expires_in": 14400
    // }

    access_token = CkJsonObjectW_stringOf(jResp,L"access_token");
    wprintf(L"New Access Token: %s\n",access_token);

    // Perhaps update our Dropbox JSON file with the new access token.
    // (The existing refresh token does not change, and can be used over and over to mint new access tokens.)
    CkJsonObjectW_UpdateString(json,L"access_token",access_token);

    CkJsonObjectW_WriteFile(json,L"qa_data/tokens/dropbox.json");


    CkHttpW_Dispose(http);
    CkJsonObjectW_Dispose(json);
    CkHttpRequestW_Dispose(req);
    CkHttpResponseW_Dispose(resp);
    CkStringBuilderW_Dispose(sbResponseBody);
    CkJsonObjectW_Dispose(jResp);

    }