title: How to check a form in modal without making it un-closeable
body: <p>I want to check a form in a modal if its inputText is correct and update the form when it's not, but my solution makes my modal un-close-able. Has anyone a workaround that works with BootsFaces and the Java classes only? </p>
  
  <pre><code>&lt;b:modal id="setBackupPeriodM" title="Backup-Periode verändern" styleClass="modalPseudoClass"
                       closable="false"
                       closeOnEscape="true"&gt;
                  &lt;b:form id="setBackupPeriodF"&gt;
                      &lt;p&gt;Legen Sie fest in welchen Abständen automatische Backups erstellt werden sollen&lt;/p&gt;
                      &lt;b:inputText id="backupPeriodInput"
                                   value="#{backupConfig.backupPeriod}"
                                   label="Tage"
                                   required="true"
                                   requiredMessage="Bitte geben Sie eine Zeit ein."
                                   large-screen="two-thirds"&gt;
                          &lt;f:convertNumber integerOnly="true"/&gt;
                          &lt;f:validateLongRange minimum="1"/&gt;
                      &lt;/b:inputText&gt;
                      &lt;b:row&gt;
                          &lt;b:column&gt;
                              &lt;b:button largeScreen="half"  value="Abbrechen"
                                        dismiss="modal" onclick="return false;"/&gt;
                              &lt;b:commandButton largeScreen="half" update="@form"
                                               dismiss="modal"
                                               value="Speichern" look="success"/&gt;
                          &lt;/b:column&gt;
                      &lt;/b:row&gt;
                  &lt;/b:form&gt;
              &lt;/b:modal&gt;
  </code></pre>