Feat: Use one-way data flow to synchronize the form data to the canvas #3221 (#7977)

### What problem does this PR solve?

Feat: Use one-way data flow to synchronize the form data to the canvas
#3221

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/form/message-form/index.tsx

@@ -9,14 +9,37 @@ import {
   FormLabel,
   FormMessage,
 } from '@/components/ui/form';
+import { zodResolver } from '@hookform/resolvers/zod';
 import { X } from 'lucide-react';
-import { useFieldArray } from 'react-hook-form';
+import { useFieldArray, useForm } from 'react-hook-form';
 import { useTranslation } from 'react-i18next';
+import { z } from 'zod';
 import { INextOperatorForm } from '../../interface';
+import { useValues } from './use-values';
+import { useWatchFormChange } from './use-watch-change';
 
-const MessageForm = ({ form }: INextOperatorForm) => {
+const MessageForm = ({ node }: INextOperatorForm) => {
   const { t } = useTranslation();
 
+  const values = useValues(node);
+
+  const FormSchema = z.object({
+    content: z
+      .array(
+        z.object({
+          value: z.string(),
+        }),
+      )
+      .optional(),
+  });
+
+  const form = useForm({
+    defaultValues: values,
+    resolver: zodResolver(FormSchema),
+  });
+
+  useWatchFormChange(node?.id, form);
+
   const { fields, append, remove } = useFieldArray({
     name: 'content',
     control: form.control,

web/src/pages/agent/form/message-form/use-values.ts

@@ -0,0 +1,25 @@
+import { RAGFlowNodeType } from '@/interfaces/database/flow';
+import { isEmpty } from 'lodash';
+import { useMemo } from 'react';
+import { convertToObjectArray } from '../../utils';
+
+const defaultValues = {
+  content: [],
+};
+
+export function useValues(node?: RAGFlowNodeType) {
+  const values = useMemo(() => {
+    const formData = node?.data?.form;
+
+    if (isEmpty(formData)) {
+      return defaultValues;
+    }
+
+    return {
+      ...formData,
+      content: convertToObjectArray(formData.content),
+    };
+  }, [node]);
+
+  return values;
+}

web/src/pages/agent/form/message-form/use-watch-change.ts

@@ -0,0 +1,24 @@
+import { useEffect } from 'react';
+import { UseFormReturn, useWatch } from 'react-hook-form';
+import useGraphStore from '../../store';
+import { convertToStringArray } from '../../utils';
+
+export function useWatchFormChange(id?: string, form?: UseFormReturn) {
+  let values = useWatch({ control: form?.control });
+  const updateNodeForm = useGraphStore((state) => state.updateNodeForm);
+
+  useEffect(() => {
+    // Manually triggered form updates are synchronized to the canvas
+    if (id && form?.formState.isDirty) {
+      values = form?.getValues();
+      let nextValues: any = values;
+
+      nextValues = {
+        ...values,
+        content: convertToStringArray(values.content),
+      };
+
+      updateNodeForm(id, nextValues);
+    }
+  }, [form?.formState.isDirty, id, updateNodeForm, values]);
+}