[tech debt] Convert EuiFormControlLayout from a class to a function c…

…omponent

- which will allow us to more easily use hooks etc for styles

packages/eui/src/components/form/form_control_layout/form_control_layout.tsx

@@ -8,22 +8,23 @@
 
 import React, {
   cloneElement,
-  Component,
+  FunctionComponent,
   HTMLAttributes,
   ReactElement,
   ReactNode,
+  useCallback,
+  useMemo,
 } from 'react';
 import classNames from 'classnames';
 
-import { getIconAffordanceStyles } from './_num_icons';
+import { getIconAffordanceStyles, isRightSideIcon } from './_num_icons';
 import {
   EuiFormControlLayoutIcons,
   EuiFormControlLayoutIconsProps,
-  IconShape,
 } from './form_control_layout_icons';
 import { CommonProps } from '../../common';
 import { EuiFormLabel } from '../form_label';
-import { FormContext, FormContextValue } from '../eui_form_context';
+import { useFormContext } from '../eui_form_context';
 
 type StringOrReactElement = string | ReactElement;
 type PrependAppendType = StringOrReactElement | StringOrReactElement[];
@@ -66,174 +67,134 @@ export type EuiFormControlLayoutProps = CommonProps &
     inputId?: string;
   };
 
-export class EuiFormControlLayout extends Component<EuiFormControlLayoutProps> {
-  static contextType = FormContext;
-
-  static defaultProps = {
-    iconsPosition: 'absolute',
-  };
-
-  render() {
-    const { defaultFullWidth } = this.context as FormContextValue;
-    const {
-      children,
+export const EuiFormControlLayout: FunctionComponent<
+  EuiFormControlLayoutProps
+> = (props) => {
+  const { defaultFullWidth } = useFormContext();
+  const {
+    inputId,
+    className,
+    children,
+    icon,
+    iconsPosition,
+    clear,
+    isDropdown,
+    isLoading,
+    isInvalid,
+    isDisabled,
+    readOnly,
+    compressed,
+    prepend,
+    append,
+    fullWidth = defaultFullWidth,
+    ...rest
+  } = props;
+
+  const classes = classNames(
+    'euiFormControlLayout',
+    {
+      'euiFormControlLayout--fullWidth': fullWidth,
+      'euiFormControlLayout--compressed': compressed,
+      'euiFormControlLayout--readOnly': readOnly,
+      'euiFormControlLayout--group': prepend || append,
+      'euiFormControlLayout-isDisabled': isDisabled,
+    },
+    className
+  );
+
+  const hasDropdownIcon = !readOnly && !isDisabled && isDropdown;
+  const hasRightIcon = isRightSideIcon(icon);
+  const hasLeftIcon = icon && !hasRightIcon;
+  const hasRightIcons =
+    hasRightIcon || clear || isLoading || isInvalid || hasDropdownIcon;
+
+  const iconAffordanceStyles = useMemo(() => {
+    if (iconsPosition === 'static') return; // Static icons don't need padding affordance
+
+    return getIconAffordanceStyles({
       icon,
-      iconsPosition,
       clear,
-      fullWidth = defaultFullWidth,
-      isLoading,
-      isDisabled,
-      compressed,
-      className,
-      prepend,
-      append,
-      readOnly,
       isInvalid,
-      isDropdown,
-      inputId,
-      ...rest
-    } = this.props;
-
-    const classes = classNames(
-      'euiFormControlLayout',
-      {
-        'euiFormControlLayout--fullWidth': fullWidth,
-        'euiFormControlLayout--compressed': compressed,
-        'euiFormControlLayout--readOnly': readOnly,
-        'euiFormControlLayout--group': prepend || append,
-        'euiFormControlLayout-isDisabled': isDisabled,
-      },
-      className
-    );
-
-    const iconAffordanceStyles =
-      iconsPosition === 'absolute' // Static icons don't need padding affordance
-        ? getIconAffordanceStyles({
-            icon,
-            clear,
-            isInvalid,
-            isLoading,
-            isDropdown,
-          })
-        : undefined;
-
-    const prependNodes = this.renderSideNode('prepend', prepend, inputId);
-    const appendNodes = this.renderSideNode('append', append, inputId);
-
-    return (
-      <div className={classes} {...rest}>
-        {prependNodes}
-        <div
-          className="euiFormControlLayout__childrenWrapper"
-          style={iconAffordanceStyles}
-        >
-          {this.renderLeftIcons()}
-          {children}
-          {this.renderRightIcons()}
-        </div>
-        {appendNodes}
-      </div>
-    );
-  }
-
-  renderLeftIcons = () => {
-    const { icon, iconsPosition, compressed } = this.props;
-
-    const leftCustomIcon =
-      icon && (icon as IconShape)?.side !== 'right' ? icon : undefined;
-
-    return leftCustomIcon ? (
-      <EuiFormControlLayoutIcons
-        side="left"
-        icon={leftCustomIcon}
-        iconsPosition={iconsPosition}
-        compressed={compressed}
-      />
-    ) : null;
-  };
-
-  renderRightIcons = () => {
-    const {
-      icon,
-      iconsPosition,
-      clear,
-      compressed,
       isLoading,
-      isInvalid,
-      isDisabled,
-      readOnly,
-      isDropdown,
-    } = this.props;
-    const hasDropdownIcon = !readOnly && !isDisabled && isDropdown;
-
-    const rightCustomIcon =
-      icon && (icon as IconShape)?.side === 'right' ? icon : undefined;
-
-    const hasRightIcons =
-      rightCustomIcon || clear || isLoading || isInvalid || hasDropdownIcon;
-
-    return hasRightIcons ? (
-      <EuiFormControlLayoutIcons
-        side="right"
-        icon={rightCustomIcon}
-        iconsPosition={iconsPosition}
-        compressed={compressed}
-        clear={clear}
-        isLoading={isLoading}
-        isInvalid={isInvalid}
-        isDropdown={hasDropdownIcon}
+      isDropdown: hasDropdownIcon,
+    });
+  }, [iconsPosition, icon, clear, isInvalid, isLoading, hasDropdownIcon]);
+
+  return (
+    <div className={classes} {...rest}>
+      <EuiFormControlLayoutSideNodes
+        side="prepend"
+        nodes={prepend}
+        inputId={inputId}
       />
-    ) : null;
-  };
-
-  renderSideNode(
-    side: 'append' | 'prepend',
-    nodes?: PrependAppendType,
-    inputId?: string
-  ) {
-    if (!nodes) {
-      return;
-    }
-
-    if (typeof nodes === 'string') {
-      return this.createFormLabel(side, nodes, inputId);
-    }
-
-    const appendNodes = React.Children.map(nodes, (item, index) =>
-      typeof item === 'string'
-        ? this.createFormLabel(side, item, inputId)
-        : this.createSideNode(side, item, index)
-    );
-
-    return appendNodes;
-  }
-
-  createFormLabel(
-    side: 'append' | 'prepend',
-    string: string,
-    inputId?: string
-  ) {
-    return (
-      <EuiFormLabel
-        htmlFor={inputId}
-        className={`euiFormControlLayout__${side}`}
+      <div
+        className="euiFormControlLayout__childrenWrapper"
+        style={iconAffordanceStyles}
       >
-        {string}
+        {hasLeftIcon && (
+          <EuiFormControlLayoutIcons
+            side="left"
+            icon={icon}
+            iconsPosition={iconsPosition}
+            compressed={compressed}
+          />
+        )}
+
+        {children}
+
+        {hasRightIcons && (
+          <EuiFormControlLayoutIcons
+            side="right"
+            icon={hasRightIcon ? icon : undefined}
+            iconsPosition={iconsPosition}
+            compressed={compressed}
+            clear={clear}
+            isLoading={isLoading}
+            isInvalid={isInvalid}
+            isDropdown={hasDropdownIcon}
+          />
+        )}
+      </div>
+      <EuiFormControlLayoutSideNodes
+        side="append"
+        nodes={append}
+        inputId={inputId}
+      />
+    </div>
+  );
+};
+
+/**
+ * Internal subcomponent utility for prepend/append nodes
+ */
+const EuiFormControlLayoutSideNodes: FunctionComponent<{
+  side: 'append' | 'prepend';
+  nodes?: PrependAppendType; // For some bizarre reason if you make this the `children` prop instead, React doesn't properly override cloned keys :|
+  inputId?: string;
+}> = ({ side, nodes, inputId }) => {
+  const className = `euiFormControlLayout__${side}`;
+
+  const renderFormLabel = useCallback(
+    (label: string) => (
+      <EuiFormLabel htmlFor={inputId} className={className}>
+        {label}
       </EuiFormLabel>
-    );
-  }
-
-  createSideNode(
-    side: 'append' | 'prepend',
-    node: ReactElement,
-    key: React.Key
-  ) {
-    return cloneElement(node, {
-      className: classNames(
-        `euiFormControlLayout__${side}`,
-        node.props.className
-      ),
-      key: key,
-    });
-  }
-}
+    ),
+    [inputId, className]
+  );
+
+  if (!nodes) return null;
+
+  return (
+    <>
+      {React.Children.map(nodes, (node, index) =>
+        typeof node === 'string'
+          ? renderFormLabel(node)
+          : cloneElement(node, {
+              className: classNames(className, node.props.className),
+              key: index,
+            })
+      )}
+    </>
+  );
+};