如何获取Ajax返回函数并阻止文档下载onclick

Question

I have been trying to figure this out for hours. I have the following document path on and anchor tag

<a href="@link.DocumentPath" onclick="return checkAuth(@link.Id, @PasswordProtected)">@link.Title</a>

I do not want to process the href if the "checkAuth" function returns a false. Here is the "checkAuth" code.

var checkAuth = function(id, PasswordProtected) {
                    var result = null;
                    var hostname = location.hostname;
                    var host = '@System.Configuration.ConfigurationManager.AppSettings["hostroot"]';
                    if (hostname == "localhost")
                        host = "";
                    if (PasswordProtected == "1"){
                        var pass = prompt("This document is password protected", "");

                        var response = $.ajax({

                            type: "GET",
                            url: host + "/Communities/DeCryptPwd/",

                            data: {"id": id, "password": pass},
                            success: function (data) {
                                alert(data);
                                if (data == "True")
                                    result = true;
                                if (data == "False")
                                    result = false;

                            },
                            error: function (errorData) { alert(errorData); }
                        });
}

I just don't know how to stop the processing of the document on the href and return a true ... continue process, or false -- stop processing.

Just in case you need it, here is the "sever side" code called by the .ajax

public bool DeCryptPwd(int id, string password) {
    var encrypted = db.CommunityDocs.Where(x => x.Id == id).Select(x => x.Password).SingleOrDefault();

    /* Extract the bytes */
    byte[] hashBytes = Convert.FromBase64String(encrypted);
    /* Get the salt */
    byte[] salt = new byte[16];
    Array.Copy(hashBytes, 0, salt, 0, 16);
    /* Compute the hash on the password the user entered */
    var pbkdf2 = new Rfc2898DeriveBytes(password, salt, 10000);
    byte[] hash = pbkdf2.GetBytes(20);
    /* Compare the results */
    for (int i = 0; i < 20; i++)
        if (hashBytes[i + 16] != hash[i])
            return false;

    return true;
}

Answer 1

You cannot return the result from an async function from the function that contains it. So you need to change the location in the success part and return true if not protected.

However the code will currently allow them to right-click and open in new window regardless

function checkAuth = function(theLink) {
  var id = theLink.id,
      protected = theLink.getAttribute("pass") == "1",
      href = theLink.href,
      result = null,
      hostname = location.hostname,
      host = '@System.Configuration.ConfigurationManager.AppSettings["hostroot"]';
  if (hostname == "localhost")
    host = "";
  if (protected) {
    var pass = prompt("This document is password protected", "");

    var response = $.ajax({

      type: "GET",
      url: host + "/Communities/DeCryptPwd/",

      data: {
        "id": id,
        "password": pass
      },
      success: function(data) {
        alert(data);
        if (data == "True") {
          location = href;
        }
      },
      error: function(errorData) {
        alert(errorData);
      }
    });
    return !protected; // return false if protected
  }

<a href="@link.DocumentPath" onclick="return checkAuth(this)" id="@link.Id" data-pass="@PasswordProtected">@link.Title</a>