refactor(loading): update from class to function (#5054)

carbon-design-system · Jan 23, 2020 · 02ba91c · 02ba91c
1 parent 0f1f287
commit 02ba91c
Showing 1 changed file with 90 additions and 109 deletions.
diff --git a/packages/react/src/components/Loading/Loading.js b/packages/react/src/components/Loading/Loading.js
@@ -5,124 +5,105 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import PropTypes from 'prop-types';
-import React from 'react';
-import classNames from 'classnames';
 import { settings } from 'carbon-components';
+import cx from 'classnames';
+import PropTypes from 'prop-types';
+import React, { useRef } from 'react';
 import setupGetInstanceId from '../../tools/setupGetInstanceId';
 
 const { prefix } = settings;
-
 const getInstanceId = setupGetInstanceId();
 
-export default class Loading extends React.Component {
-  constructor(props) {
-    super(props);
-    this.instanceId = getInstanceId();
-  }
-
-  static propTypes = {
-    /**
-     * Specify whether you want the loading indicator to be spinning or not
-     */
-    active: PropTypes.bool,
-
-    /**
-     * Provide an optional className to be applied to the containing node
-     */
-    className: PropTypes.string,
-
-    /**
-     * Specify whether you want the loader to be applied with an overlay
-     */
-    withOverlay: PropTypes.bool,
-
-    /**
-     * Specify whether you would like the small variant of <Loading>
-     */
-    small: PropTypes.bool,
-
-    /**
-     * Specify an description that would be used to best describe the loading state
-     */
-    description: PropTypes.string,
-  };
-
-  static defaultProps = {
-    active: true,
-    withOverlay: true,
-    small: false,
-    description: 'Active loading indicator',
-  };
-
-  render() {
-    const {
-      active,
-      className,
-      withOverlay,
-      small,
-      description,
-      ...other
-    } = this.props;
-
-    const loadingClasses = classNames(`${prefix}--loading`, className, {
-      [`${prefix}--loading--small`]: small,
-      [`${prefix}--loading--stop`]: !active,
-    });
-
-    const overlayClasses = classNames(`${prefix}--loading-overlay`, {
-      [`${prefix}--loading-overlay--stop`]: !active,
-    });
-
-    const loadingId = `loading-id-${this.instanceId}`;
-    const spinnerRadius = small ? '26.8125' : '37.5';
-
-    /**
-     * Various screenreaders (JAWS, VoiceOver, NVDA...) interpret live regions differently
-     * and change their interpretations over time. The aria on the div and the label
-     * associated with the div are currently necessary for the loading state to be properly
-     * read by all screenreaders. [0]
-     *
-     * JAWS does not read the loading state unless aria-atomic is set to true and the visually
-     * hidden label is required for the loading state to be read in VoiceOver on iOS. Please
-     * do not remove without testing on these platforms.
-     *
-     * [0] https://developer.paciellogroup.com/blog/2014/03/screen-reader-support-aria-live-regions/
-     * */
-    const loading = (
-      <div
-        {...other}
-        aria-atomic="true"
-        aria-labelledby={loadingId}
-        aria-live={active ? 'assertive' : 'off'}
-        className={loadingClasses}>
-        <label id={loadingId} className={`${prefix}--visually-hidden`}>
-          {description}
-        </label>
-        <svg className={`${prefix}--loading__svg`} viewBox="-75 -75 150 150">
-          <title>{description}</title>
-          {small ? (
-            <circle
-              className={`${prefix}--loading__background`}
-              cx="0"
-              cy="0"
-              r={spinnerRadius}
-            />
-          ) : null}
+function Loading({
+  active,
+  className: customClassName,
+  withOverlay,
+  small,
+  description,
+  ...rest
+}) {
+  const { current: instanceId } = useRef(getInstanceId());
+  const loadingClassName = cx(customClassName, {
+    [`${prefix}--loading`]: true,
+    [`${prefix}--loading--small`]: small,
+    [`${prefix}--loading--stop`]: !active,
+  });
+  const overlayClassName = cx({
+    [`${prefix}--loading-overlay`]: true,
+    [`${prefix}--loading-overlay--stop`]: !active,
+  });
+  const loadingId = `loading-id-${instanceId}`;
+  const spinnerRadius = small ? '26.8125' : '37.5';
+
+  const loading = (
+    <div
+      {...rest}
+      aria-atomic="true"
+      aria-labelledby={loadingId}
+      aria-live={active ? 'assertive' : 'off'}
+      className={loadingClassName}>
+      <label id={loadingId} className={`${prefix}--visually-hidden`}>
+        {description}
+      </label>
+      <svg className={`${prefix}--loading__svg`} viewBox="-75 -75 150 150">
+        <title>{description}</title>
+        {small ? (
           <circle
-            className={`${prefix}--loading__stroke`}
+            className={`${prefix}--loading__background`}
             cx="0"
             cy="0"
             r={spinnerRadius}
           />
-        </svg>
-      </div>
-    );
-
-    return withOverlay ? (
-      <div className={overlayClasses}>{loading}</div>
-    ) : (
-      loading
-    );
-  }
+        ) : null}
+        <circle
+          className={`${prefix}--loading__stroke`}
+          cx="0"
+          cy="0"
+          r={spinnerRadius}
+        />
+      </svg>
+    </div>
+  );
+
+  return withOverlay ? (
+    <div className={overlayClassName}>{loading}</div>
+  ) : (
+    loading
+  );
 }
+
+Loading.propTypes = {
+  /**
+   * Specify whether you want the loading indicator to be spinning or not
+   */
+  active: PropTypes.bool,
+
+  /**
+   * Provide an optional className to be applied to the containing node
+   */
+  className: PropTypes.string,
+
+  /**
+   * Specify whether you want the loader to be applied with an overlay
+   */
+  withOverlay: PropTypes.bool,
+
+  /**
+   * Specify whether you would like the small variant of <Loading>
+   */
+  small: PropTypes.bool,
+
+  /**
+   * Specify an description that would be used to best describe the loading state
+   */
+  description: PropTypes.string,
+};
+
+Loading.defaultProps = {
+  active: true,
+  withOverlay: true,
+  small: false,
+  description: 'Active loading indicator',
+};
+
+export default Loading;