Save image in database and render image from database

Firstly, We can save image in database as a byte array. Here, We will create a webapi which accept image as a base64 string. And further, we will convert the base64 string image into byte array and save it in mysql database. 

Datatype for MYSQL to save byte array is LONGBLOB.

Example

Properties class

public class UserInfo
{
    [Required]
    public string FirstName { get; set; }

    [Required]
    public string LastName { get; set; }

    [Required]
    [EmailAddress]
    public string Email { get; set; }

    public string UserImage { get; set; }//Base64 string

    public string ImageMimeType { get; set; }
}

API controller

[RoutePrefix("api/Account")]
public class AccountController : ApiController
{
    [HttpGet]
    [Route("SaveUserInfo")]
    [AppAuthorization]
    public IHttpActionResult SaveUserInfo(UserInfo model)
    {
        if (model != null)
        {
            try
            {
                if (ModelState.IsValid)
                {                    
                    var res = _userRepository.InsertUserInfo(model);
                    return Ok(res);
                }
                else
                {
                    return Content<object>(HttpStatusCode.InternalServerError, new { Status = false, Message = "Invalid model." });
                }
            }
            catch (Exception ex)
            {
                return Content<object>(HttpStatusCode.InternalServerError, new { Status = false, Message = ex.Message });
            }
        }
        else
        {
            return Content<object>(HttpStatusCode.InternalServerError, new { Status = false, Message = "Please provide model." });
        }
    }  
}

Business logic class

public class UserRepository : IUserRepository
{
    Dictionary<string, object> _sqlParams;

    public object InsertUserInfo(UserInfo model)
    {
       if (model.UserPic != null && model.UserPic != "")
       {
           _sqlParams = new Dictionary<string, object>();
           _sqlParams["FirstName "] = model.FirstName;
           _sqlParams["LastName "] = model.LastName;
           _sqlParams["Email"] = model.Email;
           _sqlParams["ImageBytes"] = Convert.FromBase64String(model.UserImage);
           _sqlParams["ImageName"] = model.FirstName;
           _sqlParams["MimeType"] = model.PicMimeType;     

          long userId = DBUtility.ExecuteInsertSql(SqlQueryConstants.InsertUserInfo, _sqlParams);

           return new {Status = true, Data = http://www.url.com:8098/UserImage/" + userId };//This url will render image
        }
        else
        {
           return new {Status = false, Message = "Please provide your image." };
        }
     }
}

Now, (http://www.url.com/Images/UserImage/" + userId) user will get this url to render the user image. 
This url basically hits the image controller and userImage action which will read image byte array from database and render image.

Image Controller

[AllowCrossSiteJsonAttribute]
public class ImagesController : Controller
{
   [Route("UserImage/{userId}")]
   public ActionResult UserImage(int userId)
   {
      var user = _userRepository.GetUserInfo(userId);//Get user info
      return new FileContentResult(user.ImageBytes, user.MimeType);          
   }
}

MVC Authorization filter

MVC supports 4 types of filter

• Authorization
• Action
• Result
• Exception

Authorization filter

It is executed after the user is authenticated in MVC life-cycle. It is basically used to authorize user from resources of your application. You can create your own custom authorization filter. A class which extend AuthorisationFilterAttribute class and overrides its OnAuthorization() method is authorization filter.

Example - Suppose you need to access user data from WEB API by providing authorization token. 

Controller

[RoutePrefix("api/Account")]

public class AccountController : ApiController

{

    [HttpGet]

    [Route("GetUserAppProfile")]

    [AppAuthorization]

    public IHttpActionResult GetUserProfile()

    {

        try

        {

            long userId = Convert.ToInt64(Request.Headers.GetValues("UserId").FirstOrDefault());

            var res = _userRepository.GetUserAppProfile(userId);

            return Ok(res);

        }

        catch (Exception ex)

        {

            return Content<object>(HttpStatusCode.InternalServerError, new { Status = false, Message = ex.Message });

        }

    }

}

Custom filer
        public override void OnAuthorization(System.Web.Http.Controllers.HttpActionContext actionContext)
        {
            if (!actionContext.Request.Headers.Contains("AuthToken"))
            {
                actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized, new { Status = false, Message = "Token is missing" });
            }
            else
            {
                string authToken = actionContext.Request.Headers.GetValues("AuthToken").FirstOrDefault();

                if (string.IsNullOrEmpty(authToken))
                {
                    actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized, new { Status = false, Message = "Token is missing" });
                }
                else
                {
                    long userId = userService.AuthorizeAppUser(authToken);

                    if (userId != null)
                    {
                        actionContext.Request.Headers.Add("UserId", userId.ToString());
                    }
                    else
                    {
                        actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized, new { Status = false, Message = "Invalid token" });
                    }
                }               
            }
            base.OnAuthorization(actionContext);
        }//End
    }

Before execution of action method, This custom authorization filter will execute and check for authentication token in header if token doesn't exist. It will straight forward return the status and message. And will not execute the action method.