Generate PDF and attach to send email c#

Question

Good afternoon guys, I have a modal, where the user can send an email, in this modal, I loaded a HTML, so that I can generate the PDF and attach to send in the email. But I’ve seen several articles on the Internet, and I’m even a little confused, in which line of reasoning should I follow.

Follow in the API how the email is sent:

 [HttpPut]
    [Route("sendEmail")]
    [Authorize(AuthenticationSchemes = "Bearer", Policy = WriteBudgetPolicy.Name)]
    public async Task<IActionResult> SendEmail(EmailProposalsViewModel obj)
    {
        var company = _companyAppService.GetUnique(obj.CompanyId);
        var result = new ReturnViewModel { Model = company };
        try
        {

            await Util.SendEmailProposalsAsync(obj.Email, company.Email, company.Password, company.Port.Value, company.Server, obj.Message, obj.Subject, company.Name);
        }
        catch (Exception ex)
        {
            result.Errors = new Error { Key = "SendEmail", Value = ex.Message };
        }
        return ApplicationResult(result);
    }


  public static Task SendEmailProposalsAsync(string destinatario, string remetente, string password, int port, string host, string message, string subject, string displayName)
    {

        var msg = new MailMessage
        {
            From = new MailAddress(remetente, displayName),
            To = { destinatario },
            Subject = subject,
            Body = message,
            IsBodyHtml = true,
        };

        var smtpCliente = new SmtpClient(host, port);
        smtpCliente.UseDefaultCredentials = false;
        var credentials = new NetworkCredential(remetente, password);
        smtpCliente.Credentials = credentials;
        smtpCliente.EnableSsl = false;
        if (host == "gmail.com")
        {
            smtpCliente.Host = "smtp.gmail.com";
            smtpCliente.EnableSsl = true;
        }

        if (host == "yahoo.com.br")
        {
            smtpCliente.Host = "smtp.mail.yahoo.br";
        }

        if (host == "hotmail.com")
        {
            smtpCliente.Host = "smtp.live.com";
            smtpCliente.EnableSsl = true;
        }

        if (host == "live.com")
        {
            smtpCliente.Host = "smtp.live.com";
            smtpCliente.EnableSsl = true;
        }

        smtpCliente.Send(msg);

        return Task.FromResult(0);
    }

The front-end is in angular, it would be possible to generate the PDF and send by email, without needing to save(that would be ideal)? Utilizdo .net core

Answer 1

The front end is a presentation layer. As the name says, it should be used (only) for presentation. Since nothing that comes from the front end is reliable, however much you have any logic in it should be repeated/validated in the backend.

Transposing to your case, a "simple" PDF to be attached in an email, if done at the front end, is subject to changes by the user.

Given this short preface, it DOES NOT generate your pdf on the front end. It could even be "emulated" to have a more elegant presentation for its users, however, it should be generated, even in memory, in the back-end.

Is it possible to generate a PDF with . net core? Yes, playing fast on google you should find a dozen options, paid, free, open source, to taste. Searching for "PDF" in nuget.org you will find more than 2,000 results.

Regarding the code presented...

For a share SendEmail, it does not seem reasonable to use the verb PUT. The POST would be more widely applied in this case.

Although it is a somewhat controversial task, try to give names with some meaning to their variables. obj is not very suggestive to know what it is.

Sending an email "inside" an http request is questionable. Sending an email can be time consuming and should be done in the background. Depending on the case, to avoid excessive complexity, "one can" send the request in the middle.

Regardless of whether or not to send the email in a "synchronous" way, it should not "ever" be done in a controller. A service layer should be responsible for this.

Finally, e-mail should be sent via a transactional email service. Many of the "traditional" providers like gmail are blocking the use of smtp with user and password. Where permitted, even, specific "passwords" are used for this use. Alternatively, Oauth should be used.