UX: Specify pattern and maxlength for 2FA input fields.

app/assets/javascripts/discourse/templates/mobile/modal/login.hbs

@@ -46,6 +46,8 @@
         </div>
         {{#second-factor-form}}
           {{text-field value=loginSecondFactor
+              pattern='[0-9]{6}'
+              maxlength='6'
               id="login-second-factor"
               autocorrect="off"
               autocapitalize="off"

app/assets/javascripts/discourse/templates/modal/login.hbs

@@ -34,7 +34,13 @@
           </table>
         </div>
         {{#second-factor-form}}
-          {{text-field value=loginSecondFactor id="login-second-factor" autocorrect="off" autocapitalize="off" autofocus="autofocus"}}
+          {{text-field value=loginSecondFactor
+              pattern='[0-9]{6}'
+              maxlength='6'
+              id="login-second-factor"
+              autocorrect="off"
+              autocapitalize="off"
+              autofocus="autofocus"}}
         {{/second-factor-form}}
       </form>
     {{/if}}

app/assets/javascripts/discourse/templates/preferences-second-factor.hbs

@@ -20,7 +20,9 @@
       <div class="control-group">
         <div class="controls">
           {{text-field value=second_factor_token
-              id="second_factor_token"
+              pattern='[0-9]{6}'
+              maxlength='6'
+              id="second-factor-token"
               classNames="input-large"
               autofocus="autofocus"}}
         </div>
@@ -69,6 +71,8 @@
 
           <div class="controls">
             {{text-field value=second_factor_token
+                pattern='[0-9]{6}'
+                maxlength='6'
                 id="second-factor-token"
                 classNames="input-large"
                 autofocus="autofocus"}}

app/views/session/email_login.html.erb

@@ -10,7 +10,7 @@
       <%= form_tag(method: "post") do%>
         <h2><%=t "login.second_factor_title" %></h2>
         <%= label_tag(:second_factor_token, t("login.second_factor_description")) %>
-        <div><%= text_field_tag(:second_factor_token) %></div>
+        <div><%= text_field_tag(:second_factor_token, pattern: '[0-9]{6}', maxlength: 6) %></div>
         <%= submit_tag(t("submit"), class: "btn btn-large btn-primary") %>
       <%end%>
     </div>

app/views/users/admin_login.html.erb

@@ -10,7 +10,7 @@
       <% if @second_factor_required %>
         <%=form_tag({}, method: :put) do %>
           <%= label_tag(:second_factor_token, t('login.second_factor_description')) %>
-          <%= text_field_tag(:second_factor_token, nil, autofocus: true) %><br><br>
+          <%= text_field_tag(:second_factor_token, nil, autofocus: true, pattern: '[0-9]{6}', maxlength: 6) %><br><br>
           <%= submit_tag t('submit')%>
         <% end %>
       <% end %>