fix: loop variable

ui/src/workflow-canvas/config/node-data.ts

@@ -394,7 +394,20 @@ export const loopNode = {
           y: 200,
           id: 'loop-start-node',
           type: 'loop-start-node',
-          properties: { config: { fields: [], globalFields: [] }, fields: [], showNode: true, stepName: '开始', globalFields: [] },
+          properties: {
+            config: {
+              // 循环引擎内置的输出参数（index/item），只读展示，用户不可增删改
+              fields: [
+                { label: '下标', value: 'index' },
+                { label: '循环元素', value: 'item' },
+              ],
+              globalFields: [],
+            },
+            fields: [],
+            showNode: true,
+            stepName: '开始',
+            globalFields: [],
+          },
         },
       ],
     },
@@ -410,6 +423,7 @@ export const loopStartNode = {
   properties: {
     stepName: '循环开始',
     config: {
+      // 循环引擎内置的输出参数（index/item），只读展示，用户不可增删改
       fields: [
         { label: '下标', value: 'index' },
         { label: '循环元素', value: 'item' },

ui/src/workflow-canvas/nodes/loop-start-node/component/LoopFieldDialog.vue

@@ -28,6 +28,7 @@
 import { reactive, ref } from 'vue'
 import { cloneDeep } from 'lodash'
 import type { FormInstance } from 'element-plus'
+import { isLoopBuiltinField } from '../constant'
 
 defineOptions({ name: 'LoopFieldDialog' })
 const emit = defineEmits<{ refresh: [data: { field: string; label: string }, index?: number] }>()
@@ -42,6 +43,16 @@ const rules = reactive({
   field: [
     { required: true, message: '请输入变量名', trigger: 'blur' },
     { pattern: /^[a-zA-Z0-9_]+$/, message: '变量名只能包含英文字母、数字、下划线', trigger: 'blur' },
+    {
+      validator: (_rule: unknown, value: string, callback: (error?: Error) => void) => {
+        if (isLoopBuiltinField(value)) {
+          callback(new Error('此变量名为循环引擎内置，不可使用'))
+        } else {
+          callback()
+        }
+      },
+      trigger: 'blur',
+    },
   ],
 })
 

ui/src/workflow-canvas/nodes/loop-start-node/component/LoopFieldTable.vue

@@ -38,18 +38,14 @@ import { cloneDeep, set } from 'lodash'
 import type { BaseNodeModel } from '@logicflow/core'
 import LoopFieldDialog from './LoopFieldDialog.vue'
 import { MsgError } from '@/utils/message'
+import { isLoopBuiltinField } from '../constant'
 
 defineOptions({ name: 'LoopFieldTable' })
 const props = defineProps<{ nodeModel: BaseNodeModel }>()
 
 type WorkflowGraphModel = BaseNodeModel['graphModel'] & { refresh_loop_fields?: (fields: Array<{ label: string; value: string }>) => void }
 type LoopInputField = { field: string; label: string }
 
-const DEFAULT_FIELDS: LoopInputField[] = [
-  { field: 'index', label: '下标' },
-  { field: 'item', label: '循环元素' },
-]
-
 const fieldDialogRef = ref<InstanceType<typeof LoopFieldDialog>>()
 const loopInputFieldList = ref<LoopInputField[]>([])
 
@@ -85,11 +81,10 @@ function sync() {
 
 onMounted(() => {
   const properties = props.nodeModel.properties as { loop_input_field_list?: LoopInputField[] }
-  if (Array.isArray(properties.loop_input_field_list)) {
-    loopInputFieldList.value = cloneDeep(properties.loop_input_field_list)
-  } else {
-    loopInputFieldList.value = cloneDeep(DEFAULT_FIELDS)
-  }
+  // 内置参数（index/item）由循环引擎提供，作为只读输出参数展示，不进入用户可配置的循环变量列表
+  loopInputFieldList.value = (Array.isArray(properties.loop_input_field_list) ? cloneDeep(properties.loop_input_field_list) : []).filter(
+    (item) => !isLoopBuiltinField(item.field),
+  )
   sync()
 })
 </script>

ui/src/workflow-canvas/nodes/loop-start-node/constant.ts

@@ -0,0 +1,8 @@
+// 循环引擎自带的输出参数（内置，界面上不展示、不可被用户修改）
+export const LOOP_BUILTIN_FIELDS = [
+  { field: 'index', label: '下标' },
+  { field: 'item', label: '循环元素' },
+] as const
+
+export const isLoopBuiltinField = (value?: string) =>
+  !!value && LOOP_BUILTIN_FIELDS.some((item) => item.field === value)

ui/src/workflow-canvas/nodes/loop-start-node/index.ts

@@ -1,6 +1,7 @@
 import LoopStartNodeVue from './index.vue'
 import { WorkflowNodeModel, WorkflowNodeView } from '@/workflow-canvas/core/workflow-node'
 import { WorkflowNodeType, type WorkflowNodeField } from '@/workflow-canvas/types'
+import { isLoopBuiltinField, LOOP_BUILTIN_FIELDS } from './constant'
 
 interface LoopStartNodeProperties {
   config?: { fields?: Array<{ label: string; value: string }>; globalFields?: unknown[] }
@@ -9,13 +10,24 @@ interface LoopStartNodeProperties {
 }
 
 class LoopStartNodeModel extends WorkflowNodeModel {
+  override setAttributes() {
+    super.setAttributes()
+    // 循环引擎内置的 index/item 作为只读输出参数，始终保留在节点自身配置里，保证输出区一定展示
+    const config = (this.properties.config ?? {}) as { fields?: unknown[]; globalFields?: unknown[] }
+    this.properties.config = {
+      ...config,
+      fields: LOOP_BUILTIN_FIELDS.map((item) => ({ label: item.label, value: item.field })),
+    }
+  }
+
   override getNodeFieldList(): WorkflowNodeField[] {
     const properties = this.properties as LoopStartNodeProperties
-    const inputFields =
-      properties.loop_input_field_list && properties.loop_input_field_list.length
-        ? properties.loop_input_field_list.map((item) => ({ field: item.field ?? item.variable ?? '', label: item.label ?? '' }))
-        : (properties.config?.fields ?? []).map((field) => ({ field: field.value, label: field.label }))
-    const loopFields = inputFields.map((item) => ({ label: item.label, value: item.field })).filter((field) => Boolean(field.value))
+    const inputFields = properties.loop_input_field_list
+      ? properties.loop_input_field_list
+      : (properties.config?.fields ?? []).map((field) => ({ field: field.value, label: field.label, variable: undefined }))
+    const loopFields = inputFields
+      .map((item) => ({ label: item.label ?? '', value: item.field ?? item.variable ?? '' }))
+      .filter((field) => Boolean(field.value) && !isLoopBuiltinField(field.value))
     return [{ value: 'loop', label: '循环变量', type: 'loop', children: loopFields }, ...super.getNodeFieldList()]
   }
 }

ui/src/workflow-canvas/nodes/loop-start-node/index.vue

@@ -25,6 +25,7 @@ import type { BaseNodeModel } from '@logicflow/core'
 import NodeContainer from '@/workflow-canvas/core/node-container/index.vue'
 import LoopFieldTable from './component/LoopFieldTable.vue'
 import { copyText } from '@/utils/clipboard'
+import { isLoopBuiltinField } from './constant'
 
 defineOptions({ name: 'WorkflowLoopStartNode' })
 const getModel = inject('getModel') as () => BaseNodeModel
@@ -40,6 +41,6 @@ const loopInputFields = computed(() => {
   const list = (model.properties as { loop_input_field_list?: LoopInputField[] }).loop_input_field_list ?? []
   return list
     .map((item) => ({ label: item.label ?? item.field ?? '', value: item.field ?? item.variable ?? '' }))
-    .filter((field) => Boolean(field.value))
+    .filter((field) => Boolean(field.value) && !isLoopBuiltinField(field.value))
 })
 </script>