callback () {
    if (this.params && this.params.callback) {
      return this.params.callback
    }

    return false
  }
/**
   * User defined callback name for file select.
   * @returns {boolean}
   */
User defined callback name for file select.
@returns {boolean}
User defined callback name for file select . @returns { boolean }
callback () {
    if (this.params && this.params.callback) {
      return this.params.callback
    }
    return false
  }
callback ( ) { if ( this . params && this . params . callback ) { return this . params . callback } return false }
User defined callback name for file select.
User defined callback name for file select .