feat: add destroyOnUnregister property (#206)

Author: vvasin

docs/lib.md

@@ -18,6 +18,7 @@ This component serves as the primary entry point for drawing dynamic forms.
 | Monaco                  | `React.ComponentType<MonacoEditorProps>` |          | [MonacoEditor](https://github.com/react-monaco-editor/react-monaco-editor) component for Monaco [Input](./config.md#inputs)                               |
 | search                  | `string \| function`                     |          | A string or function for performing a form search                                                                                                         |
 | withoutInsertFFDebounce | `boolean`                                |          | Flag that disables the delay before inserting data into the final-form store                                                                              |
+| destroyOnUnregister     | `boolean`                                |          | If true, the value of a field will be destroyed when that field is unregistered. Defaults to true                                                         |
 | generateRandomValue     | `function`                               |          | Function that is necessary to generate a random value                                                                                                     |
 
 ### Controller

src/lib/core/components/Form/DynamicField.tsx

@@ -1,8 +1,8 @@
 import React from 'react';
 
+import get from 'lodash/get';
 import isFunction from 'lodash/isFunction';
 import isString from 'lodash/isString';
-import get from 'lodash/get';
 import {isValidElementType} from 'react-is';
 import type {MonacoEditorProps} from 'react-monaco-editor/lib/types';
 
@@ -30,6 +30,7 @@ export interface DynamicFieldProps {
     search?: string | ((spec: Spec, input: FieldValue, name: string) => boolean);
     generateRandomValue?: (spec: StringSpec) => string;
     withoutInsertFFDebounce?: boolean;
+    destroyOnUnregister?: boolean;
     mutators?: DynamicFormMutators;
     __mirror?: WonderMirror;
 }
@@ -42,13 +43,14 @@ export const DynamicField: React.FC<DynamicFieldProps> = ({
     generateRandomValue,
     search,
     withoutInsertFFDebounce,
+    destroyOnUnregister = true,
     mutators: externalMutators,
     __mirror,
 }) => {
     const DynamicFormsCtx = useCreateContext();
     const SearchContext = useCreateSearchContext();
     const {tools, store} = useStore(name);
-    const watcher = useIntegrationFF(store, withoutInsertFFDebounce);
+    const watcher = useIntegrationFF(store, withoutInsertFFDebounce, destroyOnUnregister);
     const {mutatorsStore, mutateDFState} = useMutators(externalMutators);
     const {store: searchStore, setField, removeField, isHiddenField} = useSearchStore();
 

src/lib/core/components/Form/hooks/useIntegrationFF.tsx

@@ -10,7 +10,11 @@ import {Field as FinalFormField, useForm} from 'react-final-form';
 import {AsyncValidateError, BaseValidateError, DynamicFieldStore, FieldValue} from '../types';
 import {transformArrOut} from '../utils';
 
-export const useIntegrationFF = (store: DynamicFieldStore, withoutDebounce?: boolean) => {
+export const useIntegrationFF = (
+    store: DynamicFieldStore,
+    withoutDebounce?: boolean,
+    destroyOnUnregister?: boolean,
+) => {
     const form = useForm();
 
     const watcher = React.useMemo(() => {
@@ -64,7 +68,7 @@ export const useIntegrationFF = (store: DynamicFieldStore, withoutDebounce?: boo
 
     React.useEffect(() => {
         return () => {
-            if (store.name) {
+            if (store.name && destroyOnUnregister) {
                 form.change(store.name, undefined);
             }
         };