facebook image share

example

if (XMLHttpRequest.prototype.sendAsBinary === undefined) {
    XMLHttpRequest.prototype.sendAsBinary = function(string) {
        var bytes = Array.prototype.map.call(string, function(c) {
            return c.charCodeAt(0) & 0xff;
        });
        this.send(new Uint8Array(bytes).buffer);
    };
}

FB.PostImage = function(authToken, data, message) {
    var boundary = "----image" + new Date().valueOf();
    
    form =  "--" + boundary + "\r\n";
    form += "Content-Disposition: form-data; name=\"source\"; filename=\"image.png\"\r\n";
    form += "Content-Type: image/png\r\n\r\n";
    form += data;
    form += "\r\n";
    form += "--" + boundary + "--\r\n";
    
    var xhr = new XMLHttpRequest();
    xhr.open("POST", "https://graph.facebook.com/me/photos?access_token=" + authToken + "&message=" + message, true);
    xhr.onload = function() {
        console.log(xhr.responseText);
    };
    xhr.setRequestHeader("Content-Type", "multipart/form-data; boundary=" + boundary);
    xhr.sendAsBinary(form);
}

var data = atob($("#canvas-container canvas").last().get(0).toDataURL("image/png").replace("data:image/png;base64,", ""));
                
FB.login(function(response) {
  if (response.authResponse) {
    FB.PostImage(response.authResponse.accessToken, data, "test case");
  }
});