Feat: Add StringTransform operator #3221 (#8520)

### What problem does this PR solve?

Feat: Add StringTransform operator #3221

### Type of change


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

web/src/pages/agent/form/components/query-variable.tsx

@@ -6,15 +6,23 @@ import {
   FormLabel,
   FormMessage,
 } from '@/components/ui/form';
-import { useMemo } from 'react';
+import { ReactNode, useMemo } from 'react';
 import { useFormContext } from 'react-hook-form';
 import { useTranslation } from 'react-i18next';
 import { VariableType } from '../../constant';
 import { useBuildQueryVariableOptions } from '../../hooks/use-get-begin-query';
 
-type QueryVariableProps = { name?: string; type?: VariableType };
+type QueryVariableProps = {
+  name?: string;
+  type?: VariableType;
+  label?: ReactNode;
+};
 
-export function QueryVariable({ name = 'query', type }: QueryVariableProps) {
+export function QueryVariable({
+  name = 'query',
+  type,
+  label,
+}: QueryVariableProps) {
   const { t } = useTranslation();
   const form = useFormContext();
 
@@ -34,7 +42,11 @@ export function QueryVariable({ name = 'query', type }: QueryVariableProps) {
       name={name}
       render={({ field }) => (
         <FormItem>
-          <FormLabel tooltip={t('chat.modelTip')}>{t('flow.query')}</FormLabel>
+          {label || (
+            <FormLabel tooltip={t('chat.modelTip')}>
+              {t('flow.query')}
+            </FormLabel>
+          )}
           <FormControl>
             <SelectWithSearch
               options={finalOptions}

web/src/pages/agent/form/string-transform-form/index.tsx

@@ -0,0 +1,161 @@
+import { FormContainer } from '@/components/form-container';
+import {
+  Form,
+  FormControl,
+  FormField,
+  FormItem,
+  FormLabel,
+  FormMessage,
+} from '@/components/ui/form';
+import { MultiSelect } from '@/components/ui/multi-select';
+import { RAGFlowSelect } from '@/components/ui/select';
+import { buildOptions } from '@/utils/form';
+import { zodResolver } from '@hookform/resolvers/zod';
+import { useCallback, useMemo } from 'react';
+import { useForm, useWatch } from 'react-hook-form';
+import { z } from 'zod';
+import {
+  StringTransformDelimiter,
+  StringTransformMethod,
+  initialStringTransformValues,
+} from '../../constant';
+import { INextOperatorForm } from '../../interface';
+import { Output, transferOutputs } from '../components/output';
+import { PromptEditor } from '../components/prompt-editor';
+import { QueryVariable } from '../components/query-variable';
+import { useValues } from './use-values';
+import { useWatchFormChange } from './use-watch-form-change';
+
+const DelimiterOptions = Object.entries(StringTransformDelimiter).map(
+  ([key, val]) => ({ label: key, value: val }),
+);
+
+export const StringTransformForm = ({ node }: INextOperatorForm) => {
+  const values = useValues(node);
+
+  const FormSchema = z.object({
+    method: z.string(),
+    split_ref: z.string().optional(),
+    script: z.string().optional(),
+    delimiters: z.array(z.string()),
+    outputs: z.object({ result: z.object({ type: z.string() }) }).optional(),
+  });
+
+  const form = useForm<z.infer<typeof FormSchema>>({
+    defaultValues: values,
+    resolver: zodResolver(FormSchema),
+  });
+
+  const method = useWatch({ control: form.control, name: 'method' });
+
+  const isSplit = method === StringTransformMethod.Split;
+
+  const outputList = useMemo(() => {
+    return transferOutputs(values.outputs);
+  }, [values.outputs]);
+
+  const handleMethodChange = useCallback(
+    (value: StringTransformMethod) => {
+      const outputs = {
+        ...initialStringTransformValues.outputs,
+        result: {
+          type:
+            value === StringTransformMethod.Merge ? 'string' : 'Array<string>',
+        },
+      };
+      form.setValue('outputs', outputs);
+    },
+    [form],
+  );
+
+  useWatchFormChange(node?.id, form);
+
+  return (
+    <Form {...form}>
+      <form
+        className="space-y-5 px-5 "
+        autoComplete="off"
+        onSubmit={(e) => {
+          e.preventDefault();
+        }}
+      >
+        <FormContainer>
+          <FormField
+            control={form.control}
+            name="method"
+            render={({ field }) => (
+              <FormItem>
+                <FormLabel>method</FormLabel>
+                <FormControl>
+                  <RAGFlowSelect
+                    {...field}
+                    options={buildOptions(StringTransformMethod)}
+                    onChange={(value) => {
+                      handleMethodChange(value);
+                      field.onChange(value);
+                    }}
+                  ></RAGFlowSelect>
+                </FormControl>
+                <FormMessage />
+              </FormItem>
+            )}
+          />
+          {isSplit && (
+            <QueryVariable
+              label={<FormLabel>split_ref</FormLabel>}
+              name="split_ref"
+            ></QueryVariable>
+          )}
+          {isSplit || (
+            <FormField
+              control={form.control}
+              name="script"
+              render={({ field }) => (
+                <FormItem>
+                  <FormLabel>script</FormLabel>
+                  <FormControl>
+                    <PromptEditor {...field} showToolbar={false}></PromptEditor>
+                  </FormControl>
+                  <FormMessage />
+                </FormItem>
+              )}
+            />
+          )}
+          <FormField
+            control={form.control}
+            name="delimiters"
+            render={({ field }) => (
+              <FormItem>
+                <FormLabel>delimiters</FormLabel>
+                <FormControl>
+                  {isSplit ? (
+                    <MultiSelect
+                      options={DelimiterOptions}
+                      onValueChange={field.onChange}
+                      variant="inverted"
+                      {...field}
+                    />
+                  ) : (
+                    <RAGFlowSelect
+                      {...field}
+                      options={DelimiterOptions}
+                    ></RAGFlowSelect>
+                  )}
+                </FormControl>
+                <FormMessage />
+              </FormItem>
+            )}
+          />
+          <FormField
+            control={form.control}
+            name="outputs"
+            render={() => <div></div>}
+          />
+        </FormContainer>
+      </form>
+      <div className="p-5">
+        <Output list={outputList}></Output>
+      </div>
+    </Form>
+  );
+};

web/src/pages/agent/form/string-transform-form/use-values.ts

@@ -0,0 +1,27 @@
+import { RAGFlowNodeType } from '@/interfaces/database/flow';
+import { isEmpty } from 'lodash';
+import { useMemo } from 'react';
+import {
+  initialStringTransformValues,
+  StringTransformMethod,
+} from '../../constant';
+
+export function useValues(node?: RAGFlowNodeType) {
+  const values = useMemo(() => {
+    const formData = node?.data?.form;
+
+    if (isEmpty(formData)) {
+      return initialStringTransformValues;
+    }
+
+    return {
+      ...formData,
+      delimiters:
+        formData.method === StringTransformMethod.Merge
+          ? formData.delimiters[0]
+          : formData.delimiters,
+    };
+  }, [node?.data?.form]);
+
+  return values;
+}

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

@@ -0,0 +1,26 @@
+import { useEffect } from 'react';
+import { UseFormReturn, useWatch } from 'react-hook-form';
+import { StringTransformMethod } from '../../constant';
+import useGraphStore from '../../store';
+
+export function useWatchFormChange(id?: string, form?: UseFormReturn<any>) {
+  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;
+
+      if (
+        values.delimiters !== undefined &&
+        values.method === StringTransformMethod.Merge
+      ) {
+        nextValues.delimiters = [values.delimiters];
+      }
+
+      updateNodeForm(id, nextValues);
+    }
+  }, [form?.formState.isDirty, id, updateNodeForm, values]);
+}