Sending WhatsApp Messages from a Win32 C++ Program - Part 1

• Download Software_SG_SendWhatsApp - 985 KB
• Download WhatsApp-Michael-Haephrati - 5.1 KB

Introduction

I was looking for a simple API for sending WhatsApp messages to a group of programmers at Secured Globe, Inc. There are several service providers and we have chosen one of them (WhatsAppMate) and started a free trial. However, their code samples for using their services are in almost any programming language except for C++. So we wrote our own C++ class for that purpose. Please read Part 2 as well. 

Background

WhatsApp is a multi-platform free service for chatting via video or voice and for sending messages to individuals or groups, including files, media, etc. WhatsApp is better than the old SMS because it is free and has more features. During our day to day work, we need to set up all sort of alerts to be sent to a group who share a job or work on a feature and when that's done automatically, it makes life easier to be notified.

Using the Code

For the GitHub repo, see this one (the class) and this one (the MFC based tool).

There are several types of messages that can be sent, including individual or group messages and with or without a photo or PDF file attached to them. You can read about it in this page.

Here are the building blocks you need to have. Alternatively, I will later attach a compiled (.exe) test application.

//
#define    GroupAdmin                <YOUR GROUP ADMIN MOBILE PHONE>
#define GroupName                <YOUR GROUP NAME>
#define CLIENT_ID                <YOUR CLIENT ID>
#define CLIENT_SECRET            <YOUR CLIENT SECRET>

#define GROUP_API_SERVER        L"api.whatsmate.net"
#define GROUP_API_PATH          L"/v3/whatsapp/group/text/message/12"
#define IMAGE_SINGLE_API_URL    L"http://api.whatsmate.net/v3/whatsapp/group/image/message/12"

//

Connecting to the Internet

First, we open an Internet connection and connect to the API service:

hOpenHandle = InternetOpen(_T("HTTP"), INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
if (hOpenHandle == NULL)
{
    return false;
}

hConnectHandle = InternetConnect(hOpenHandle,
    GROUP_API_SERVER,
    INTERNET_DEFAULT_HTTP_PORT,
    NULL, NULL, INTERNET_SERVICE_HTTP,
    0, 1);

if (hConnectHandle == NULL)
{
    InternetCloseHandle(hOpenHandle);
    return false;
}

Opening a Request

const wchar_t *AcceptTypes[] = { _T("application/json"),NULL };
HINTERNET hRequest = HttpOpenRequest(hConnectHandle, _T("POST"),
                     GROUP_API_PATH, NULL, NULL, AcceptTypes, 0, 0);

if (hRequest == NULL)
{
    InternetCloseHandle(hConnectHandle);
    InternetCloseHandle(hOpenHandle);
    return false;
}

The Header

Next, we post the Header which is composed using the following code:

std::wstring HeaderData;

HeaderData += _T("X-WM-CLIENT-ID: ");
HeaderData += _T(CLIENT_ID);
HeaderData += _T("\r\nX-WM-CLIENT-SECRET: ");
HeaderData += _T(CLIENT_SECRET);
HeaderData += _T("\r\n");
HttpAddRequestHeaders(hRequest, HeaderData.c_str(), HeaderData.size(), NULL);

Shooting the Message

Now we are ready to shoot our message to the group:

std::wstring WJsonData;
WJsonData += _T("{");
WJsonData += _T("\"group_admin\":\"");
WJsonData += groupAdmin;
WJsonData += _T("\",");
WJsonData += _T("\"group_name\":\"");
WJsonData += groupName;
WJsonData += _T("\",");
WJsonData += _T("\"message\":\"");
WJsonData += message;
WJsonData += _T("\"");
WJsonData += _T("}");

const std::string JsonData(WJsonData.begin(), WJsonData.end());

bResults = HttpSendRequest(hRequest, NULL, 0, (LPVOID)(JsonData.c_str()), JsonData.size());

Checking the Result

The recipient will see a WhatsApp message like this:

But to be sure, at this point we need to know if everything went well. That is done by querying the result of our Http Request.

The StatusText we expect if it worked is "OK".

TCHAR StatusText[BUFFER_LENGTH] = { 0 };
DWORD StatusTextLen = BUFFER_LENGTH;
HttpQueryInfo(hRequest, HTTP_QUERY_STATUS_TEXT, &StatusText, &StatusTextLen, NULL);
bResults = (StatusTextLen && wcscmp(StatusText, L"OK")==FALSE);

Using the SGWhatsApp Class

Now we can see how we use our class.

#include "SGWhatsApp.h"

int _tmain(int argc, _TCHAR* argv[])
{    
    SGWhatsApp sender;
    sender.SendGroupMessage(GroupAdmin, GroupName, _T("hi"));
    return 0;
}

History

• 3^rd November, 2018: Initial version

Thank you

Thanks for Ivan Voloschuk for his help.