# Approval instance status change
By subscribing to the event of approval instance status change, the approval instance status message will be pushed to the developer after the instance status changes.
1. After you create an approval, the [PENDING] status will be pushed.
2. If any approver rejects the approval, the [REJECTED] status will be pushed.
3. After all approvers permit, the [APPROVED] status will be pushed.
4. If the approval initiator cancels the approval, the [CANCELED] status will be pushed.
5. If the approval definition is deleted by the administrator, the [DELETED] status will be pushed.
6. When approved instance is reverted by creator, status is [REVERTED].
7. Approval instance timeout unprocessed is closed, push [OVERTIME_CLOSE] status
8. Manually restore the approval instance that has timed out and push the [OVERTIME_RECOVER] status

**Approval instance status message**:
```json
{
     "ts": "1502199207.7171419",
     "uuid": "bc447199585340d1f3728d26b1c0297a", 
     "token": "41a9425ea7df4536a7623e38fa321bae",
     "type": "event_callback",
     "event": { 
         "app_id": "cli_xxx", 
         "tenant_key":"xxx", 
         "type": "approval_instance", 
         "approval_code": "7C468A54-8745-2245-9675-08B7C63E7A85",
         "instance_code": "81D31358-93AF-92D6-7425-01A5D67C4E71", 
         "status": "PENDING",
         "operate_time": 1666079207003, // Note that the data type of this field is int64
         "instance_operate_time": "1666079207003",
         "uuid":"6525bffb"
    }
}
```
**Message description**:
| Field         | Type          | Description          |
| --------- | --------------- | --------- |
| `type` | `string` | approval_instance;<br>Fixed field |
| `approval_code` | `string` | Approval definition code | 
| `instance_code` | `string` | Approval instance code |
| `status` | `string` | Instance status;<br>PENDING - In progress;<br>APPROVED - Approved;<br>REJECTED - Rejected;<br>CANCELED - Canceled;<br>DELETED - Deleted;<br>REVERTED - Reverted;<br>OVERTIME_CLOSE - unprocessed is closed;<br>OVERTIME_RECOVER - Manually restore the approval instance |
| `instance_operate_time` | `string` | Event occurrence time |
| `uuid` | `string` | The approval instance defines a custom unique ID, which is passed in when the interface is created for approval. |

### Sample code for event subscriptions

For event subscription process, refer to:[Event Subscription overview](https://open.feishu.cn/document/ukTMukTMukTM/uUTNz4SN1MjL1UzM)，Guide for beginners:[Tutorial](https://open.feishu.cn/document/uAjLw4CM/uMzNwEjLzcDMx4yM3ATM/develop-an-echo-bot/introduction)

**

package main

import (
        "context"
        "fmt"

larkcore "github.com/larksuite/oapi-sdk-go/v3/core"
        larkevent "github.com/larksuite/oapi-sdk-go/v3/event"
        "github.com/larksuite/oapi-sdk-go/v3/event/dispatcher"
        "github.com/larksuite/oapi-sdk-go/v3/service/approval/old"
        larkws "github.com/larksuite/oapi-sdk-go/v3/ws"
)

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/golang-sdk-guide/preparations
func main() {
        // 注册事件 Register event
        eventHandler := dispatcher.NewEventDispatcher("", "").
                OnCustomizedEvent("approval_instance", func(ctx context.Context, event *larkevent.EventReq) error {
                        fmt.Printf("[ OnCustomizedEvent access ], type: message, data: %s\n", string(event.Body))
                        return nil
                })

// 构建 client Build client
        cli := larkws.NewClient("YOUR_APP_ID", "YOUR_APP_SECRET",
                larkws.WithEventHandler(eventHandler),
                larkws.WithLogLevel(larkcore.LogLevelDebug),
        )

// 建立长连接 Establish persistent connection
        err := cli.Start(context.Background())

if err != nil {
                panic(err)
        }
}

# SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/python--sdk/preparations-before-development
import lark_oapi as lark

def do_customized_event(data: lark.CustomizedEvent) -> None:
    print(f'[ do_customized_event access ], type: message, data: {lark.JSON.marshal(data, indent=4)}')

# 注册事件 Register event
event_handler = lark.EventDispatcherHandler.builder("", "") \
    .register_p1_customized_event("approval_instance", do_customized_event) \
    .build()

def main():
    # 构建 client Build client
    cli = lark.ws.Client("APP_ID", "APP_SECRET",
                        event_handler=event_handler, log_level=lark.LogLevel.DEBUG)
    # 建立长连接 Establish persistent connection
    cli.start()

if __name__ == "__main__":
    main()

package com.example.sample;

import java.nio.charset.StandardCharsets;
import com.lark.oapi.core.request.EventReq;
import com.lark.oapi.event.CustomEventHandler;
import com.lark.oapi.event.EventDispatcher;
import com.lark.oapi.ws.Client;

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/java-sdk-guide/preparations
public class Sample {
    // 注册事件 Register event
    private static final EventDispatcher EVENT_HANDLER = EventDispatcher.newBuilder("", "")
            .onCustomizedEvent("approval_instance", new CustomEventHandler() {
                @Override
                public void handle(EventReq event) throws Exception {
                    System.out.printf("[ onCustomizedEvent access ], type: message, data: %s\n", new String(event.getBody(), StandardCharsets.UTF_8));
                }
            })
            .build();

public static void main(String[] args) {
        // 构建 client Build client
        Client client = new Client.Builder("APP_ID", "APP_SECRET")
                .eventHandler(EVENT_HANDLER)
                .build();
        // 建立长连接 Establish persistent connection
        client.start();
    }
}

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/nodejs-sdk/preparation-before-development
import * as Lark from '@larksuiteoapi/node-sdk';
const baseConfig = {
    appId: 'APP_ID',
    appSecret: 'APP_SECRET'
}
// 构建 client Build client
const wsClient = new Lark.WSClient(baseConfig);
// 建立长连接 Establish persistent connection
wsClient.start({
    // 注册事件 Register event
    eventDispatcher: new Lark.EventDispatcher({}).register({
        'approval_instance': async (data) => {
            console.log(data);
        }
    })
});

package main

import (
        "context"
        "fmt"
        "net/http"

larkcore "github.com/larksuite/oapi-sdk-go/v3/core"
        "github.com/larksuite/oapi-sdk-go/v3/core/httpserverext"
        larkevent "github.com/larksuite/oapi-sdk-go/v3/event"
        "github.com/larksuite/oapi-sdk-go/v3/event/dispatcher"
        "github.com/larksuite/oapi-sdk-go/v3/service/approval/old"
)

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/golang-sdk-guide/preparations
func main() {
        // 注册事件 Register event
        eventHandler := dispatcher.NewEventDispatcher("", "").
                OnCustomizedEvent("approval_instance", func(ctx context.Context, event *larkevent.EventReq) error {
                        fmt.Printf("[ OnCustomizedEvent access ], type: message, data: %s\n", string(event.Body))
                        return nil
                })

// 创建路由处理器 Create route handler
        http.HandleFunc("/webhook/event", httpserverext.NewEventHandlerFunc(handler, larkevent.WithLogLevel(larkcore.LogLevelDebug)))

err := http.ListenAndServe(":7777", nil)

if err != nil {
                panic(err)
        }
}

# SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/python--sdk/preparations-before-development
from flask import Flask
from lark_oapi.adapter.flask import *
import lark_oapi as lark

app = Flask(__name__)

def do_customized_event(data: lark.CustomizedEvent) -> None:
    print(f'[ do_customized_event access ], type: message, data: {lark.JSON.marshal(data, indent=4)}')

# 注册事件 Register event
event_handler = lark.EventDispatcherHandler.builder("", "") \
    .register_p1_customized_event("approval_instance", do_customized_event) \
    .build()

# 创建路由处理器 Create route handler
@app.route("/webhook/event", methods=["POST"])
def event():
    resp = handler.do(parse_req())
    return parse_resp(resp)

if __name__ == "__main__":
    app.run(port=7777)

package com.lark.oapi.sample.event;

import java.nio.charset.StandardCharsets;
import com.lark.oapi.core.request.EventReq;
import com.lark.oapi.event.CustomEventHandler;
import com.lark.oapi.sdk.servlet.ext.ServletAdapter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/java-sdk-guide/preparations
@RestController
public class EventController {

// 注册事件 Register event
    private static final EventDispatcher EVENT_HANDLER = EventDispatcher.newBuilder("verificationToken", "encryptKey")
            .onCustomizedEvent("approval_instance", new CustomEventHandler() {
                @Override
                public void handle(EventReq event) throws Exception {
                    System.out.printf("[ onCustomizedEvent access ], type: message, data: %s\n", new String(event.getBody(), StandardCharsets.UTF_8));
                }
            })
            .build();

// 注入 ServletAdapter 实例 Inject ServletAdapter instance
    @Autowired
    private ServletAdapter servletAdapter;

// 创建路由处理器 Create route handler
    @RequestMapping("/webhook/event")
    public void event(HttpServletRequest request, HttpServletResponse response)
            throws Throwable {
        // 回调扩展包提供的事件回调处理器 Callback handler provided by the extension package
        servletAdapter.handleEvent(request, response, EVENT_DISPATCHER);
    }
}

// SDK 使用说明 SDK user guide：https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/server-side-sdk/nodejs-sdk/preparation-before-development
import http from 'http';
import * as lark from '@larksuiteoapi/node-sdk';

// 注册事件 Register event
const eventDispatcher = new lark.EventDispatcher({
    encryptKey: '',
    verificationToken: '',
}).register({
    'approval_instance': async (data) => {
        console.log(data);
        return 'success';
    },
});

const server = http.createServer();
// 创建路由处理器 Create route handler
server.on('request', lark.adaptDefault('/webhook/event', eventDispatcher));
server.listen(3000);