# ButtonPrimitive
To implement ButtonPrimitive component into your project you'll need to add the import:
```jsx
import ButtonPrimitive from "@kiwicom/orbit-components/lib/primitives/ButtonPrimitive";
```
After adding import into your project you can use it simply like:
```jsx
Hello!
```
## Props
Table below contains all types of the props available in ButtonPrimitive component.
| Name | Type | Default | Description |
| :--------------- | :------------------------- | :--------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| asComponent | `string \| React.Element` | `"button"` | The component used for the root node. |
| ariaControls | `string` | | Id of the element the button controls. |
| ariaExpanded | `boolean` | | Tells screen reader the controlled element from `ariaControls` is expanded. |
| arialCurrent | `string` | | Indicates whether the element represents the current item within within a container or set of related elements. |
| background | `string` | | The background of the ButtonPrimitive on initial state. |
| backgroundHover | `string` | | The background of the ButtonPrimitive on hover state. |
| backgroundActive | `string` | | The background of the ButtonPrimitive on active state. |
| backgroundFocus | `string` | | The background of the ButtonPrimitive on focus state. |
| boxShadow | `string` | | The box-shadow of the ButtonPrimitive on initial state. |
| boxShadowHover | `string` | | The box-shadow of the ButtonPrimitive on hover state. |
| boxShadowActive | `string` | | The box-shadow of the ButtonPrimitive on active state. |
| boxShadowFocus | `string` | | The box-shadow of the ButtonPrimitive on focus state. |
| children | `React.Node` | | The content of the ButtonPrimitive. [See Functional specs](#functional-specs). |
| circled | `boolean` | `false` | If `true`, the ButtonPrimitive will have circular shape. |
| contentAlign | `string` | `center` | The justify-content of inner container that wraps icons and the children. |
| contentWidth | `string` | | The with of inner container that wraps the children. |
| dataTest | `string` | | Optional prop for testing purposes. |
| disabled | `boolean` | `false` | If `true`, the ButtonPrimitive will be disabled. |
| external | `boolean` | `false` | If `true`, the ButtonPrimitive opens link in a new tab. [See Functional specs](#functional-specs) |
| fontSize | `string` | | The font-size of the ButtonPrimitive. |
| fontWeight | `string` | | The font-weight of the ButtonPrimitive. |
| foreground | `string` | | The color of the text inside ButtonPrimitive on initial state. |
| foregroundHover | `string` | | The color of the text inside ButtonPrimitive on hover state. |
| foregroundFocus | `string` | | The color of the text inside ButtonPrimitive on active state. |
| foregroundActive | `string` | | The color of the text inside ButtonPrimitive on focus state. |
| fullWidth | `boolean` | `false` | If `true`, the ButtonPrimitive will grow up to the full width of its container. |
| height | `string` | | The height of the ButtonPrimitive. |
| href | `string` | | The URL of the link to open when ButtonPrimitive is clicked. [See Functional specs](#functional-specs) |
| iconLeft | `React.Node` | | The displayed icon on the left. |
| iconRight | `React.Node` | | The displayed icon on the right. |
| icons | [`Icons`](#icons) | | Object property for passing down settings for icons inside the ButtonPrimitive. |
| loading | `boolean` | `false` | If `true`, the loading glyph will be displayed and ButtonPrimitive will be disabled. |
| onClick | `event => void \| Promise` | | Function for handling onClick event. |
| padding | `string` | | The inner padding of the ButtonPrimitive. |
| rel | `string` | | Specifies the rel of an element. [See Functional specs](#functional-specs) |
| role | `string` | | Specifies the role of an element. |
| spaceAfter | `enum` | | Additional `margin-bottom` after component. [See this docs](https://github.com/kiwicom/orbit/tree/master/packages/orbit-components/src/common/getSpacingToken) |
| submit | `boolean` | `false` | If `true`, the ButtonPrimitive will have `type="submit"` attribute, otherwise `type="button"`. |
| title | `string` | | Adds `aria-label`. |
| tabIndex | `string \| number` | `"0"` | Specifies the tab order of an element. |
| width | `string` | | The width of the ButtonPrimitive. Can be any string - `100px`, `20%`. |
### Icons
`icons` is special object property of ButtonPrimitive where you can pass settings that belongs to icons that is possible to use inside this component.
| Name | Type | Description |
| :--------------- | :------- | :------------------------------------------------------ |
| width | `string` | The width of icons inside the ButtonPrimitive. |
| height | `string` | The height of icons inside the ButtonPrimitive. |
| leftMargin | `string` | The margin of the left icon inside the ButtonPrimitive. |
| rightMargin | `string` | The margin of the left icon inside the ButtonPrimitive. |
| foreground | `string` | The color of the icon inside the ButtonPrimitive. |
| foregroundHover | `string` | The color of the icon inside the ButtonPrimitive. |
| foregroundFocus | `string` | The color of the icon inside the ButtonPrimitive. |
| foregroundActive | `string` | The color of the icon inside the ButtonPrimitive. |
## Functional specs
- When the `external` is specified, `noopener` value will be automatically added to attribute `rel` for security reason.
* By passing the `href` prop into Button, it will render into `a` element. If you pass `asComponent` prop it will override this logic.
- If you want to render **Icon only ButtonPrimitive**, you just need to let `children` prop empty and set up any `icon` you want to use.
* If you want to use the `asComponent` prop then **YourComponent** should accept at least `className`. Otherwise it won't be rendered with proper styling, e.g.:
```jsx
const YourComponent = props =>
Title
```
If you specify the children of **YourComponent** component, it will override the children prop of ButtonPrimitive component, e.g.:
```jsx
const YourComponent = props => YourComponent
;
```
## Accessibility
A button is mainly used for indicating an action, submitting a data, opening a modal etc. If you want to use ButtonPrimitive for navigation consider using a `` for that.
- Use `ariaControls` prop to add `aria-controls` attribute to establish the relationship between button and element which is controlled by it. `aria-controls` works only with a unique `id` of an element.
- Use `ariaExpands` prop to add `aria-expands` to indicate screenreaders, that element controlled by button through `ariaControls` is expanded or not.
- Use `disabled` prop to indicate users that button is inactive and they can't interact with it.
- Use `role` and `tabIndex` when you are rendering `Button` to non-actionable HTML element as `div` or `span`. However, this should be done only in edge-cases as it is anti-pattern behavior.
- Use `title` to add `aria-label` when you need to add extra information to screen readers or there is no `children` presented to be used as label.