SendGrid HTML Email with Embedded Images

Demonstrates how to send an HTML email with embedded images using SendGrid.
Chilkat C Downloads

#include <C_CkHttpRequest.h>
#include <C_CkHttp.h>
#include <C_CkBinData.h>
#include <C_CkStringBuilder.h>
#include <C_CkJsonObject.h>
#include <C_CkHttpResponse.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttpRequest req;
    HCkHttp http;
    HCkBinData bdJpg;
    HCkStringBuilder sbHtml;
    HCkJsonObject json;
    HCkHttpResponse resp;

    success = FALSE;

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

    req = CkHttpRequest_Create();
    http = CkHttp_Create();

    // First.. load a JPG file and build an HTML img tag with the JPG data inline encoded.
    // Our HTML img tag will look like this:
    // <img src="data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEA3ADcAA..." alt="" style="border-width:0px;" />
    bdJpg = CkBinData_Create();
    success = CkBinData_LoadFile(bdJpg,"qa_data/jpg/starfish.jpg");
    if (success == FALSE) {
        printf("Failed to load JPG file.\n");
        CkHttpRequest_Dispose(req);
        CkHttp_Dispose(http);
        CkBinData_Dispose(bdJpg);
        return;
    }

    // Note: HTML containing embedded base64 image data may not be visible in all email clients.
    // For example, GMail might not display the image, but viewing in Outlook might be OK.
    sbHtml = CkStringBuilder_Create();
    CkStringBuilder_Append(sbHtml,"<html><body><b>This is a test<b><br /><img src=\"data:image/jpeg;base64,");
    // Append the base64 image data to sbHtml.
    CkBinData_GetEncodedSb(bdJpg,"base64",sbHtml);
    CkStringBuilder_Append(sbHtml,"\" alt=\"\" style=\"border-width:0px;\" /></body></html>");

    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"personalizations[0].to[0].email","matt@chilkat.io");
    CkJsonObject_UpdateString(json,"personalizations[0].to[0].name","Matt");
    CkJsonObject_UpdateString(json,"from.email","admin@chilkatsoft.com");
    CkJsonObject_UpdateString(json,"subject","Test HTML email with images");
    CkJsonObject_UpdateString(json,"content[0].type","text/html");
    CkJsonObject_UpdateSb(json,"content[0].value",sbHtml);

    CkHttp_putAuthToken(http,"SENDGRID_API_KEY");

    resp = CkHttpResponse_Create();
    success = CkHttp_HttpJson(http,"POST","https://api.sendgrid.com/v3/mail/send",json,"application/json",resp);
    if (success == FALSE) {
        printf("%s\n",CkHttp_lastErrorText(http));
        CkHttpRequest_Dispose(req);
        CkHttp_Dispose(http);
        CkBinData_Dispose(bdJpg);
        CkStringBuilder_Dispose(sbHtml);
        CkJsonObject_Dispose(json);
        CkHttpResponse_Dispose(resp);
        return;
    }

    printf("response status code: %d\n",CkHttpResponse_getStatusCode(resp));
    // Display the response.
    // If successful, the response code is 202 and the response body string is empty.
    // (The response body string may also be empty for error response codes.)
    printf("%s\n",CkHttpResponse_bodyStr(resp));


    CkHttpRequest_Dispose(req);
    CkHttp_Dispose(http);
    CkBinData_Dispose(bdJpg);
    CkStringBuilder_Dispose(sbHtml);
    CkJsonObject_Dispose(json);
    CkHttpResponse_Dispose(resp);

    }