[Vuejs]-Is v-bind called when referencing a component in Vue?

Because Vue does not update View right update when data changes so you should submit in nextTick

submitMessage () {
  // Submit data to server
  return api.createMessage( messageToSend, ( message ) => {
    this.latestMessageAttachmentUrl = './messages/' + message.id + '/attachments';
    this.$nextTick(() => {
      this.$refs.uploadFiles.submit();
    })
  } );
}