导出

FlexTreeMnaager和FlexTree支持将树导出为Json和List格式。

下面以下面的树为例，说明如何导出树。

Root
- A
- B
- C

toJson

FlexTreeManager、FlexTree和FlexTreeNode均支持toJson方法，用于将树导出为Json格式。

toJson(
    options?: FlexTreeExportJsonOptions<Fields, KeyFields>
): FlexTreeExportJsonFormat<Fields, KeyFields>

interface FlexTreeExportJsonOptions<
    Fields extends Record<string, any> = object,
    KeyFields extends CustomTreeKeyFields = DefaultTreeKeyFields,
> {
    childrenField?: string
    level?: number // 限定导出的级别
    fields?: (keyof IFlexTreeNode<Fields, KeyFields>)[]
    includeKeyFields?: boolean
    countField?: string // 指定后附加后代数量字段
}

参数

参数	类型	默认	描述
`options`	`FlexTreeExportJsonOptions`	无	导出选项
`options.childrenField`	`string`	`'children'`	子节点字段名
`options.level`	`number`	无	限定导出的级别
`options.fields`	`(keyof IFlexTreeNode<Fields, KeyFields>)[]`	无	导出的字段
`options.includeKeyFields`	`boolean`	`false`	是否导出关键字段
`options.countField`	`string`	无	后代数量字段名

返回一个JSON对象，子节点字段名默认为children，可以通过options.childrenField参数自定义。

type FlexTreeExportJsonFormat<
  Fields extends Record<string, any> = object,
  KeyFields extends CustomTreeKeyFields = DefaultTreeKeyFields,
  TreeNode extends IFlexTreeNode<Fields, KeyFields> = IFlexTreeNode<Fields, KeyFields>,
  NodeId = NonUndefined<KeyFields["id"]>[1],
> = TreeNode & {
  children?: FlexTreeExportJsonFormat<Fields, KeyFields, TreeNode, NodeId>[];
};

示例

import type { FlexTreeOptions, IFlexTreeNode } from "flextree";
import { FlexTreeManager, FlexTree, FlexTreeVerifyError } from "flextree";

import SqliteAdapter from "flextree-sqlite-adapter";
const sqliteDriver = new SqliteAdapter();
await sqliteDriver.open();

const tree = new FlexTree("tree", {
  adapter: sqliteDriver,
});
await tree.load();

tree.toJson();

输出的结果如下：

json

{
  "id": 1,
  "name": "root",
  "children": [
    {
      "id": 2,
      "name": "A",
      "children": [
        { "id": 3, "name": "A1" },
        { "id": 4, "name": "A2" },
        { "id": 5, "name": "A3" }
      ]
    },
    {
      "id": 6,
      "name": "B",
      "children": [
        { "id": 7, "name": "B1" },
        { "id": 8, "name": "B2" },
        { "id": 9, "name": "B3" }
      ]
    },
    {
      "id": 10,
      "name": "C",
      "children": [
        { "id": 11, "name": "C1" },
        { "id": 12, "name": "C2" },
        { "id": 13, "name": "C3" }
      ]
    }
  ]
}

说明
- toJson方法会将树导出为Json格式，可以通过options.level参数限定导出的级别。
- toJson方法可以在FlexTree和FlexTreeNode中调用。
- 可以通过options.fields参数指定导出的字段
- 默认情况下不会导出leftValue和rightValue字段,可以通过options.includeKeyFields参数指定是否导出关键字段
- 可以通过options.childrenField参数指定子节点字段名

countField 后代数量

指定options.countField后，每个节点会附加一个表示后代节点数量的字段（叶子节点为0）：

await manager.toJson({ countField: "count" })
// { "id": 1, "name": "root", "count": 12, "children": [
//    { "id": 2, "name": "A", "count": 3, "children": [...] },
//    ...
// ] }

数量按(rightValue - leftValue - 1) / 2计算，恒为全量后代数——不受level截断影响（level: 2 导出时根节点的数量仍包含深层后代）
countField与id同地位：指定fields过滤时照样附加，不受includeKeyFields控制
与节点已有字段重名时会抛出FlexTreeError
启用回收站时为可见口径：默认视角下数量不含已被回收的节点（与导出内容一致）；includeRecyclebin: true时为物理全集数量

toList

FlexTreeManager、FlexTree和FlexTreeNode均支持toList方法，用于将树导出为带pid字段的list节点数组格式。

toList(
    options?: FlexTreeExportListOptions<Fields, KeyFields>
): FlexTreeExportListFormat<Fields, KeyFields>
interface FlexTreeExportListOptions<
    Fields extends Record<string, any> = object,
    KeyFields extends CustomTreeKeyFields = DefaultTreeKeyFields,
> {
    pidField?: string
    level?: number // 限定导出的级别
    fields?: (keyof IFlexTreeNode<Fields, KeyFields>)[]
    includeKeyFields?: boolean
    countField?: string // 指定后附加后代数量字段
}

参数

参数	类型	默认	描述
`options`	`FlexTreeExportListOptions`	无	导出选项
`options.pidField`	`string`	`'pid'`	父节点字段名
`options.level`	`number`	无	限定导出的级别
`options.fields`	`(keyof IFlexTreeNode<Fields, KeyFields>)[]`	无	导出的字段
`options.includeKeyFields`	`boolean`	`false`	是否导出关键字段
`options.countField`	`string`	无	后代数量字段名

返回一个list节点数组，父节点字段名默认为pid，可以通过options.pidField参数自定义。

export type FlexTreeExportListFormat<
  Fields extends Record<string, any> = object,
  KeyFields extends CustomTreeKeyFields = DefaultTreeKeyFields,
  TreeNode extends IFlexTreeNode<Fields, KeyFields> = IFlexTreeNode<Fields, KeyFields>,
  NodeId = NonUndefined<KeyFields["id"]>[1],
  OPTIONS extends FlexTreeExportListOptions<Fields, KeyFields> = FlexTreeExportListOptions<
    Fields,
    KeyFields
  >,
> = ((OPTIONS["fields"] extends string[]
  ? Extract<TreeNode, OPTIONS["fields"][number]>
  : TreeNode) & { [P in OPTIONS["pidField"] & string]: NodeId })[];

示例

import type { FlexTreeOptions, IFlexTreeNode } from "flextree";
import { FlexTreeManager, FlexTree, FlexTreeVerifyError } from "flextree";
import SqliteAdapter from "flextree-sqlite-adapter";
const sqliteDriver = new SqliteAdapter();
await sqliteDriver.open();

const tree = new FlexTree("tree", {
  adapter: sqliteDriver,
});
await tree.load();

tree.toList();

输出的结果如下：

json

[
  { "id": 1, "name": "root", "pid": 0 },
  { "id": 2, "name": "A", "pid": 1 },
  { "id": 3, "name": "A1", "pid": 2 },
  { "id": 4, "name": "A2", "pid": 2 },
  { "id": 5, "name": "A3", "pid": 2 },
  { "id": 6, "name": "B", "pid": 1 },
  { "id": 7, "name": "B1", "pid": 6 },
  { "id": 8, "name": "B2", "pid": 6 },
  { "id": 9, "name": "B3", "pid": 6 },
  { "id": 10, "name": "C", "pid": 1 },
  { "id": 11, "name": "C1", "pid": 10 },
  { "id": 12, "name": "C2", "pid": 10 },
  { "id": 13, "name": "C3", "pid": 10 }
]

提示

toList和toJson方法均支持level参数，用于限定导出的级别。可以在FlexTree和FlexTreeNode中调用。countField的语义见上文 countField 后代数量。

getTree

FlexTreeManager提供了getTree方法，用于基于当前管理器构建一个内存中的FlexTree对象，从而可以使用FlexTree提供的丰富API（如getByPath、find、toJson、toList等）。

getTree(options?: FlexTreeOptions): FlexTree<Fields, KeyFields>

示例

const tree = manager.getTree()
await tree.load()           // FlexTree 需手动加载后才能访问
tree.getByPath('/A/A-1')

提示

FlexTreeManager还提供了toJson与toList两个异步便捷方法，内部会自动通过getTree构建并加载树后再导出：

await manager.toJson()
await manager.toList()

导出 ​

toJson ​

countField 后代数量 ​

toList ​

getTree ​

导出

toJson

countField 后代数量

toList

getTree