🚧

src/containers/index.ts

@@ -0,0 +1 @@
+export * from './multiple';

src/containers/multiple/index.ts

@@ -0,0 +1 @@
+export * from './multiple.container';

src/containers/multiple/multiple.container.tsx

@@ -0,0 +1,93 @@
+import {Component, Description, Label} from '@components';
+import {IRenderable, RenderComponent} from '@lib/renderer';
+import {IComponentProps, Values} from '@types';
+import {ComponentSchema} from 'formiojs';
+import React, {useState} from 'react';
+
+export interface IMultipleComponent extends ComponentSchema {
+  type: string;
+}
+
+export interface IMultipleProps extends IComponentProps {
+  component: IMultipleComponent;
+  value: Values;
+}
+
+/**
+ * Implements `multiple: true` behaviour.
+ *
+ * Provide a thin wrapper around a component with controls for adding multiple instances. Utilizes
+ * <RenderComponent/> to render individual instances.
+ */
+export const Multiple: React.FC<IMultipleProps> = props => {
+  const {component, form, path, value = [], setValue} = props; // FIXME: Awaits future pr.
+  const [keys, setKeys] = useState<number[]>(Array.from({length: 1}, (_, i) => i));
+
+  /** Finds next key by increasing the max key with 1. */
+  const getKey = (): number => {
+    if (!keys.length) {
+      return 0;
+    }
+    const max = Math.max(...keys);
+    return max + 1;
+  };
+
+  /** Add item. */
+  const add = () => {
+    setKeys([...keys, getKey()]);
+  };
+
+  /** Remove item at index. */
+  const remove = (index: number) => {
+    const _keys = keys.filter((_, i) => i !== index);
+    const val = value.filter((_, i) => i !== index);
+    setKeys(_keys);
+    setValue(path, val);
+  };
+
+  /** Renders individual components utilizing <RenderComponent/>. */
+  const renderComponents = () =>
+    Array.from({length: keys.length}, (_, index) => {
+      // Clone and adjust component to fit nested needs.
+      const renderable: IRenderable = {
+        ...structuredClone(component),
+        key: `${path}.${index}`, // Trigger Formik array values.
+        multiple: false, // Handled by <Multiple/>
+        description: '', // One description rendered for all components.
+        label: '', // One label rendered for all components.
+      };
+
+      return (
+        <tr key={keys[index]}>
+          <td>
+            <RenderComponent component={renderable} form={form} path={path} value={value[index]} />
+          </td>
+          <td>
+            <button onClick={() => remove(index)} aria-controls={renderable.key}>
+              Remove item
+            </button>
+          </td>
+        </tr>
+      );
+    });
+
+  return (
+    <Component {...props}>
+      <Label {...props} />
+      <table>
+        <tbody>{renderComponents()}</tbody>
+        <tfoot>
+          <tr>
+            <td>
+              <button type="button" onClick={() => add()}>
+                Add another
+              </button>
+            </td>
+          </tr>
+        </tfoot>
+      </table>
+      <table />
+      <Description {...props} />
+    </Component>
+  );
+};

src/containers/multiple/multiple.stories.tsx

@@ -0,0 +1,64 @@
+import {DEFAULT_RENDER_CONFIGURATION, RenderForm} from '@lib/renderer';
+import {expect} from '@storybook/jest';
+import type {ComponentStory, Meta} from '@storybook/react';
+import {userEvent, within} from '@storybook/testing-library';
+
+import {Multiple} from './multiple.container';
+
+const meta: Meta<typeof Multiple> = {
+  title: 'Containers / Multiple',
+  component: Multiple,
+  decorators: [],
+  parameters: {},
+};
+export default meta;
+
+export const multipleTextfields: ComponentStory<typeof RenderForm> = args => (
+  <RenderForm {...args} />
+);
+multipleTextfields.args = {
+  configuration: DEFAULT_RENDER_CONFIGURATION,
+  form: {
+    display: 'form',
+    components: [
+      {
+        type: 'textfield',
+        key: 'multiple-inputs',
+        description: 'Array of strings instead of a single string value',
+        label: 'Multiple inputs',
+        multiple: true,
+      },
+    ],
+  },
+  initialValues: {
+    'multiple-inputs': ['first value'],
+  },
+  onSubmit: () => {},
+};
+multipleTextfields.play = async ({canvasElement}) => {
+  const canvas = within(canvasElement);
+
+  // check that new items can be added
+  await userEvent.click(canvas.getByRole('button', {name: 'Add another'}));
+  const input1 = await canvas.getAllByRole('textbox')[0];
+  expect(input1).toHaveDisplayValue('first value');
+  await userEvent.clear(input1);
+  await userEvent.type(input1, 'Foo');
+  expect(input1).toHaveDisplayValue('Foo');
+
+  const input2 = await canvas.getAllByRole('textbox')[1];
+  expect(input2).toHaveDisplayValue('');
+
+  // the label & description should be rendered only once, even with > 1 inputs
+  expect(canvas.queryAllByText('Multiple inputs')).toHaveLength(1);
+  expect(canvas.queryAllByText('Array of strings instead of a single string value')).toHaveLength(
+    1
+  );
+
+  // finally, it should be possible delete rows again
+  const removeButtons = await canvas.findAllByRole('button', {name: 'Remove item'});
+  expect(removeButtons).toHaveLength(2);
+  await userEvent.click(removeButtons[0]);
+  expect(await canvas.getAllByRole('textbox')[0]).toHaveDisplayValue('');
+  expect(await canvas.getAllByRole('textbox')).toHaveLength(1);
+};

src/lib/renderer/renderer.tsx

@@ -1,6 +1,7 @@
 import {Column, Columns, Content, IColumnProps, TextField} from '@components';
+import {Multiple} from '@containers';
 import {DEFAULT_VALIDATORS, getFormErrors} from '@lib/validation';
-import {IComponentProps, IFormioForm, IRenderConfiguration, IValues} from '@types';
+import {IComponentProps, IFormioForm, IRenderConfiguration, IValues, Value, Values} from '@types';
 import {Formik, useField, useFormikContext} from 'formik';
 import {FormikHelpers} from 'formik/dist/types';
 import {Utils} from 'formiojs';
@@ -14,6 +15,9 @@ export const DEFAULT_RENDER_CONFIGURATION: IRenderConfiguration = {
     content: Content,
     textfield: TextField,
   },
+  containers: {
+    multiple: Multiple,
+  },
   validators: DEFAULT_VALIDATORS,
 };
 
@@ -79,18 +83,26 @@ export interface IRenderFormProps {
  *
  * @external {RenderContext} Provides `RenderContext`.
  */
-export const RenderForm = ({
+export const RenderForm: React.FC<IRenderFormProps> = ({
   children,
   configuration,
   form,
   formAttrs,
   initialValues = {},
   onSubmit,
-}: IRenderFormProps): React.ReactElement => {
-  const childComponents =
-    form.components?.map((c: IRenderable) => (
-      <RenderComponent key={`${c.id}-${c.key}`} component={c} form={form} />
-    )) || null;
+}) => {
+  const childComponents: React.ReactElement[] = [];
+  // TODO: Refactor types
+  Utils.eachComponent(
+    form.components,
+    (c: IRenderable, path: string) => {
+      const component = (
+        <RenderComponent key={`${c.id}-${c.key}`} component={c} form={form} path={path} />
+      );
+      childComponents.push(component);
+    },
+    true
+  );
 
   return (
     <RenderContext.Provider value={configuration}>
@@ -115,6 +127,8 @@ export const RenderForm = ({
 export interface IRenderComponentProps {
   component: IRenderable;
   form: IFormioForm;
+  path: string;
+  value?: Value | Values;
 }
 
 /**
@@ -143,10 +157,12 @@ export interface IRenderComponentProps {
  * @external {FormikContext} Expects `Formik`/`FormikContext` to be available.
  * @external {RenderContext} Expects `RenderContext` to be available.
  */
-export const RenderComponent = ({
+export const RenderComponent: React.FC<IRenderComponentProps> = ({
   component,
   form,
-}: IRenderComponentProps): React.ReactElement | null => {
+  path,
+  value = undefined,
+}) => {
   const key = component.key || OF_MISSING_KEY;
   const {setFieldValue, values} = useFormikContext();
   const Component = useComponentType(component);
@@ -165,7 +181,11 @@ export const RenderComponent = ({
     return null;
   }
 
-  const [{value, onBlur, onChange}, {error}] = field;
+  const [{onBlur, onChange}, {error}] = field;
+
+  // Allow the value to be overriden.
+  const _value = value !== undefined ? value : field[0].value;
+
   const callbacks = {onBlur, onChange};
   const errors = error?.split('\n') || []; // Reconstruct array.
 
@@ -180,7 +200,7 @@ export const RenderComponent = ({
 
   // Regular children, either from component or column.
   const childComponents = cComponents?.map(c => (
-    <RenderComponent key={`${c.id}-${c.key}`} component={c} form={form} />
+    <RenderComponent key={`${c.id}-${c.key}`} component={c} form={form} path={path} />
   ));
 
   // Columns from component.
@@ -193,12 +213,21 @@ export const RenderComponent = ({
         type: 'column',
       }}
       form={form}
+      path={path}
     />
   ));
 
   // Return the component, pass children.
   return (
-    <Component callbacks={callbacks} component={component} errors={errors} value={value}>
+    <Component
+      callbacks={callbacks}
+      component={component}
+      form={form}
+      errors={errors}
+      path={path}
+      value={_value}
+      setValue={setFieldValue}
+    >
       {childComponents || childColumns}
     </Component>
   );
@@ -212,13 +241,33 @@ export const RenderComponent = ({
 const Fallback = (props: IComponentProps) => <React.Fragment>{props.children}</React.Fragment>;
 
 /**
- * Custom hook resolving the `React.ComponentType` from `RenderContext`.
+ * Custom hook resolving the `React.ComponentType` based on the configuration in `RenderContext`.
+ * Resolving is performed in the following order:
+ *
+ *   1. - A `React.ComponentType` configured for a certain "containers" entry indicating an internal
+ *        edge case.
+ *   2. - A `React.ComponentType` configured for a certain "components" entry indicating a regular
+ *        component.
+ *   3. - A fallback component solely rendering `props.children`.
  * @external {RenderContext} Expects `RenderContext` to be available.
  */
 export const useComponentType = (
   component: IRenderable
 ): React.ComponentType<IColumnProps | IComponentProps> => {
   const renderConfiguration = useContext(RenderContext);
+  const ContainerType = useContainerConfiguration(component);
   const ComponentType = renderConfiguration.components[component.type];
-  return ComponentType || Fallback;
+  return ContainerType || ComponentType || Fallback;
+};
+
+/**
+ * Returns the applicable `containerConfiguration` (if any) for component.
+ * @see {IContainerConfiguration}
+ */
+export const useContainerConfiguration = (component: IRenderable) => {
+  const renderConfiguration = useContext(RenderContext);
+  if (component.multiple) {
+    return renderConfiguration.containers.multiple || null;
+  }
+  return null;
 };

src/types/componentprops.d.ts

@@ -2,16 +2,16 @@ import {ComponentSchema} from 'formiojs';
 import React from 'react';
 
 import {ICallbackConfiguration} from './config';
+import {IFormioForm} from './form';
 import {Value, Values} from './value';
 
-interface IComponentProps {
+export interface IComponentProps {
   callbacks: ICallbackConfiguration;
-
-  children?: React.ReactNode;
-
   component: ComponentSchema;
-
   errors: string[];
-
+  form: IFormioForm;
   value: Value | Values | undefined;
+  path: string;
+  setValue: (field: string, value: any, shouldValidate?: boolean) => void;
+  children?: React.ReactNode;
 }

src/types/config.d.ts

@@ -1,11 +1,13 @@
 import {IColumnProps} from '@components';
+import {IRenderable} from '@lib/renderer';
 import {validator} from '@lib/validation';
 import React from 'react';
 
 import {IComponentProps} from './componentprops';
 
 export interface IRenderConfiguration {
   components: IComponentConfiguration;
+  containers: IContainerConfiguration;
   validators: validator[];
 }
 
@@ -22,6 +24,21 @@ export interface ICallbackConfiguration {
 
 export type callback = (e: Event | React.BaseSyntheticEvent) => void;
 
+/**
+ * Describes a mapping between a component type (`ComponentSchema.type`) and a (React) component to
+ * render.
+ * @example `{type: "textfield"}` -> <TextField/>
+ */
 export interface IComponentConfiguration {
   [index: string]: React.ComponentType<IColumnProps | IComponentProps>;
 }
+
+/**
+ * Describes a mapping between an (internal) container type and a (React) component to render. The
+ * internal container type is not directly linked to a specific key in `ComponentSchema` but may be
+ * referenced directly by the renderer based specific conditions.
+ * @example `{multiple: "true"}` -> <Multiple/>
+ */
+export interface IContainerConfiguration {
+  [index: string]: React.ComponentType<IColumnProps | IComponentProps>;
+}

tsconfig.json

@@ -20,6 +20,7 @@
     "sourceMap": true,
     "paths": {
       "@components": ["src/components/index"],
+      "@containers": ["src/containers/index"],
       "@fixtures": ["src/fixtures/index"],
       "@lib/*": ["src/lib/*"],
       "@types": ["src/types/index"]