--- order: 11 title: FAQ --- Here are the frequently asked questions about Ant Design and antd that you should look up before you ask in the community or create a new issue. We also maintain a [FAQ issues label](http://u.ant.design/faq) for common github issues. --- ## Is there a difference between `undefined` and `null` in the controlled components of `antd`? **Yes. antd will treats `undefined` as uncontrolled but `null` as controlled components which means empty value of it.** As input element, React treats both `undefined` and `null` as uncontrolled. When the `value` is converted from a valid value to `undefined` or `null`, the component is no longer controlled, which causes some unexpected cases. But in antd, `undefined` is treated as uncontrolled, and `null` is used as an explicit empty value of controlled components. To deal with some cases (e.g. `allowClear`) like clearing the `value` when the `value` is non-primitive. If you need a component controlled with the `value` valid, just set the `value` as `null`. Note: For `options` in `Select-like` components, it is **strongly recommended not** to use `undefined` and `null` as `value` in `option`. Please use `string | number` as a valid `value` in `option`. ## Can I use internal API which is not documented on the site? NOT RECOMMEND. Internal API is not guaranteed to be compatible with future versions. It may be removed or changed in some versions. If you really need to use it, you should to make sure these API is still valid when upgrading to a new version or just lock version for usage. ## Why API request should be strict discussion? We are cautious when adding APIs because some APIs may not be abstract enough to become historical debt. For example, when there is a need to change the way of interaction, these poor abstractions may cause breaking changes. To avoid such problems, we recommend that new features be implemented through HOCs first. ## `Select Dropdown DatePicker TimePicker Popover Popconfirm` disappears when I click another popup component inside it. How do I resolve this? This is an old bug that has been fixed since `v3.11.x`. If you're using an older version, you can use ` trigger.parentElement}>` ([API reference](/components/select/#select-props)) to render a component inside the scroll area. If you need to config this globally in your application, try ` trigger.parentElement}>` ([API reference](/components/config-provider/#api)) And make sure that parentElement is `position: relative` or `position: absolute`. Related issue: [#3487](https://github.com/ant-design/ant-design/issues/3487) [#3438](https://github.com/ant-design/ant-design/issues/3438) ## How do I modify the default theme of Ant Design? See: https://ant.design/docs/react/customize-theme . ## How do I modify `Menu`/`Button`(etc.)'s style? While you can override a component's style, we don't recommend doing so. antd is not only a set of React components, but also a design specification as well. ## How to avoid breaking change when update version? antd will avoid breaking change in minor & patch version. You can safe do follow things: - Official demo usage - FAQ suggestion. Including codesandbox sample, marked as FAQ issue And which you should avoid to do: - Bug as feature. It will break in any other case (e.g. Use div as Tabs children) - Use magic code to realize requirement but which can be realized with normal API ## How to use other data-time lib like Moment.js? Please refer to [Use custom date library](/docs/react/use-custom-date-library). ## It doesn't work when I change `defaultValue` dynamically. The `defaultXxxx` (e.g. `defaultValue`) of `Input`/`Select`(etc...) only works on the first render. It is a specification of React. Please read [React's documentation](https://facebook.github.io/react/docs/forms.html#controlled-components). ## Why does modifying props in mutable way not trigger a component update? antd use shallow compare of props to optimize performance. You should always pass the new object when updating the state. Please ref [React's document](https://reactjs.org/docs/thinking-in-react.html) ## After I set the `value` of an `Input`/`Select`(etc.) component, the value cannot be changed by user's action. Try `onChange` to change `value`, and please read [React's documentation](https://reactjs.org/docs/forms.html#controlled-components). ## Components are not vertically aligned when placed in single row. Try [Space](https://ant.design/components/space/) component to make them aligned. ## antd overrides my global styles Yes, antd is designed to help you develop a complete background application. To do so, we override some global styles for styling convenience, and currently these cannot be removed or changed. More info at https://github.com/ant-design/ant-design/issues/4331 . Alternatively, follow the instructions in [How to avoid modifying global styles?](/docs/react/customize-theme#how-to-avoid-modifying-global-styles) ## I cannot install `antd` and `antd`'s dependencies in mainland China. To potentially solve this, try [npm mirror china](https://npmmirror.com) and [cnpm](https://github.com/cnpm/cnpm). ## I set `dependencies.antd` as the git repository in `package.json`, but it doesn't work. Please install `antd` with either npm or yarn. ## `message` and `notification` is lower case, but other components are capitalized. Is this a typo? No, `message` is just a function, not a React Component, thus it is not a typo that it is in lower case. ## `antd` doesn't work well in mobile. Please check [Ant Design Mobile](http://mobile.ant.design) as a possible solution, as `antd` has not been optimized to work well on mobile. You can also try the [react-component](https://github.com/react-component/) repositories which start with 'm-' 'rn-', which are also designed for mobile. ## Does `antd` supply standalone files like 'React'? Yes, you can [import `antd` with script tag](https://ant.design/docs/react/introduce#import-in-browser), but we recommend using `npm` to import `antd`, as it is simple and easy to maintain. ## How do I extend antd's components? If you need some features which should not be included in antd, try to extend antd's component with [HOC](https://gist.github.com/sebmarkbage/ef0bf1f338a7182b6775). [more](https://medium.com/@dan_abramov/mixins-are-dead-long-live-higher-order-components-94a0d2f9e750#.eeu8q01s1) ## How to get the definition which is not export? antd 会透出组件定义,但是随着重构可能导致内部一些定义命名或者属性变化。因而更推荐直接使用 Typescript 原生能力获取: antd will export mainly definitions, but not export internal definitions which may be rename or changed. So we recommend you to use Typescript's native ability to get the definition if needed: ```tsx import { Table } from 'antd'; type Props any> = Parameters[0]; type TableProps = Props>; type DataSource = TableProps['dataSource']; ``` ## Date-related components locale is not working? Please check whether import dayjs locale correctly. ```jsx import 'dayjs/locale/zh-cn'; dayjs.locale('zh-cn'); ``` Please check whether there is two version of dayjs installed. ```jsx npm ls dayjs ``` If you are using a mismatched version of dayjs with [antd's dayjs](https://github.com/ant-design/ant-design/blob/7dfc80504a36cf8952cd732a1d0c137a16d56fd4/package.json#L125) in your project. That would be a problem cause locale not working. ## How do I fix dynamic styles while using a Content Security Policy (CSP)? You can configure `nonce` by [ConfigProvider](/components/config-provider/#content-security-policy). ## When I set `mode` to `DatePicker`/`RangePicker`, why can I not select a year or month anymore? In a real world development, you may need a `YearPicker`, `MonthRangePicker` or `WeekRangePicker`. You are trying to add `mode` to `DatePicker`/`RangePicker` expected to implement those pickers. However, the `DatePicker`/`RangePicker` cannot be selected and the panels won't close now. - Reproduction link: https://codesandbox.io/s/dank-brook-v1csy - Same issues:[#15572](https://github.com/ant-design/ant-design/issues/15572), [#16436](https://github.com/ant-design/ant-design/issues/16436), [#11938](https://github.com/ant-design/ant-design/issues/11938), [#11735](https://github.com/ant-design/ant-design/issues/11735), [#11586](https://github.com/ant-design/ant-design/issues/11586), [#10425](https://github.com/ant-design/ant-design/issues/10425), [#11053](https://github.com/ant-design/ant-design/issues/11053) Like [the explanation](https://github.com/ant-design/ant-design/issues/11586#issuecomment-429189877) explains, this is because `` does not equal the `YearPicker`, nor is `` equal to `MonthRangePicker`. The `mode` property was added to support [showing time picker panel in DatePicker](https://github.com/ant-design/ant-design/issues/5190) in antd 3.0, which simply controls the displayed panel, and won't change the original date picking behavior of `DatePicker`/`RangePicker` (for instance you will still need to click date cell to finish selection in a `DatePicker`, whatever the `mode` is). Likewise,`disabledDate` [cannot work on year/month panels](https://github.com/ant-design/ant-design/issues/9008#issuecomment-358554118) of ``, but only on cells of date panel. ### Workaround You can refer to [this article](https://juejin.im/post/5cf65c366fb9a07eca6968f9) or [this article](https://www.cnblogs.com/zyl-Tara/p/10197177.html), using `mode` and `onPanelChange` to encapsulate a `YearPicker` or `MonthRangePicker` for your needs. Or you can simply upgrade to [antd@4.0](https://github.com/ant-design/ant-design/issues/16911), in which we [added more XxxPickers](https://github.com/ant-design/ant-design/issues/4524#issuecomment-480576884) to meet those requirements, and `disabledDate` could be effect on those pickers too. ## message/notification/Modal.confirm lost styles when set `prefixCls` on ConfigProvider? Static methods like message/notification/Modal.confirm are not using the same render tree as `