Improve the error message in the slices

[x4base]

No description provided.

[coveralls]

Coverage remained the same at 82.095% when pulling 0af373cb755fdb377fc795ae4d962e12974fa9d2 on x4base:slice_error_msg into cb384d0 on airbnb:master.

[mistercrunch]

I like the idea of improving the error messages but we should allow for both custom message and this introspection of the web response. What about slice.error receives both message and response and we print a nice div (perhaps expandable, with more details) depending on what is provided by the user?

[x4base]

Do you mean something like this?

      getErrorMsg: function (xhr) {
        if (xhr.statusText === "timeout") {
          return "The request timed out";
        }
        var msg = "";
        if (!xhr.responseText) {
          var status = xhr.status;
          msg += "An unknown error occurred. (Status: " + status + ")";
          if (status === 0) {
            // This may happen when the worker in gunicorn times out
            msg += " Maybe the request timed out?";
          }
        }
        return msg;
      },

, then

-      error: function (msg) {
+      error: function (msg, xhr) {
         token.find("img.loading").hide();
-        var err = '<div class="alert alert-danger">' + msg + '</div>';
+        var err = msg ? ('<div class="alert alert-danger">' + msg + '</div>')
+            : "";
+        err += '<div class="alert alert-danger">' + this.getErrorMsg(xhr) + '</div>';
         container.html(err);
         container.show();

[mistercrunch]

Yeah that looks right.

[coveralls]

Coverage decreased (-0.2%) to 81.856% when pulling d5fca084397e61fe0fded8039715b497abf80807 on x4base:slice_error_msg into cb384d0 on airbnb:master.

[x4base]

I have updated the branch

[x4base]

Updated again to solve the conflict

[coveralls]

Coverage remained the same at 81.627% when pulling b17e00f on x4base:slice_error_msg into d71a67c on airbnb:master.