Adding type and charset in json base64 value

Question

I need to change the json body responce:

{
    "id": "1581fbd2-c045-4162-9f4c-ddbca6a88d61",
    "content": "//content in base64"
    "title": "ProfileImage",
    "type": "image/jpeg",
    "created": "2023-08-03T18:55:46.736405+03:00"
}

"content" field like this:

 "content": "Data: image/jpeg; Charset: utf-8;//content in base64"

Is there a way to do it in the mapping config?

Tried adding values directly in the controller

 var result = await _mediaService.GetById(id);

            if (result == null)
            {
                return NotFound();
            }

            string base64Data = Convert.ToBase64String(result.Content);
            string metaInfo = string.Format("Data: {0}; Charset: {1}", result.Type, Encoding.UTF8.WebName);
            string base64String = metaInfo + Convert.ToBase64String(result.Content);

            var mapResult = _mapper.Map<MediaModelResponse>(result);

            var response = new
            {
                mapResult.Id,
                Content = base64String,
                mapResult.Title,
                mapResult.Created
            };

            return Ok(response);

It works but i want to find a better solution

Also tried to add a new field "ContentTest" to my model and write the result directly

mapResult.ContentTest = base64String;

Answer 1

You can move your base64 conversion logic to your Automapper configuration

cfg.CreateMap<MediaDto, MediaModelResponse>()
    .ForMember(i => i.Content, cfg => cfg.MapFrom((src, dest) =>
    {
        string metaInfo = string.Format("Data: {0}; Charset: {1}", src.Type, Encoding.UTF8.WebName);
        string base64String = metaInfo + Convert.ToBase64String(src.Content);

        return base64String;
    }));