docs: add sendable related documents

docs/tutorial/03-learning/04-use-watcher.md

@@ -563,6 +563,33 @@ const alovaInst = createAlova({
 });
 ```
 
+## Do not send request when state changes
+
+Sometimes you want not to send a request when the monitored state changes. You can control whether to send a request when the monitored state changes through the sendable attribute in the Hook configuration. The sendable attribute is a function whose parameter is the `AlovaEvent` event object. Contains the array `sendArgs` composed of the parameters passed in by the `send` function, and the `method` instance of the current request, and the function returns a `truthy/falsy` value to determine whether the request needs to be triggered when the status changes (default is `true`), **throwing an error also means not triggering the request**.
+
+```javascript
+const {
+  // ...
+  // highlight-start
+  // When the request is not sent, the value of data is the response of the last successful request
+  data,
+  // When the request is not sent, the loading value is false
+  loading
+  // highlight-end
+} = useWatcher(
+  () => getTodoList($currentPage),
+  // An array of monitored states, these state changes will trigger a request
+  [state],
+  {
+    sendable: methodInstance => {
+      // do something
+      // Send request only when state is 1
+      return state === 1;
+    }
+  }
+);
+```
+
 ## API
 
 ### Hook configuration
@@ -575,6 +602,7 @@ const alovaInst = createAlova({
 | managedStates | Additional managed states, can be updated via updateState                                                                                          | Record<string | number | symbol, any>                                                                                                                                 | -        | -       |
 | debounce      | Request debounce time (milliseconds), when passing in the array, you can set the debounce time separately according to the order of watchingStates | number                                                                                                                                                                                | number[] | -       | -   |
 | middleware    | Middleware function, [Learn about alova middleware](../advanced/middleware)                                                                        | (context: [AlovaFrontMiddlewareContext](../learning/use-request/#alovafrontmiddlewarecontext), next: [AlovaGuardNext](../learning/use-request/#alovaguardnext)) => Promise<any> | -        | -       |
+| sendable        | Whether to send a request when the monitored state changes                                                   | (methodInstance: AlovaEvent) => boolean                                                                                                                                            | () => true | -       |
 
 ### Responsive data
 

i18n/zh-CN/docusaurus-plugin-content-docs/current/tutorial/03-learning/04-use-watcher.md

@@ -562,6 +562,32 @@ const alovaInst = createAlova({
   }
 });
 ```
+## 状态改变时不发送请求
+
+有时候你希望在监听的状态改变时不发送请求，你可以通过 Hook 配置中的 sendable 属性来控制监听的状态改变时是否发送请求，sendable 属性为一个函数，它的参数为`AlovaEvent`事件对象，包含`send`函数传入的参数所组成的数组`sendArgs`，以及当前请求的`method`实例，并且该函数返回一个`truthy/falsy`值来判断本次状态改变时是否需要触发请求（默认为`true`），**抛出错误也表示不触发请求**。
+
+```javascript
+const {
+  // ...
+  // highlight-start
+  // 请求未发送时，data 值为上一次请求成功的响应
+  data,
+  // 请求未发送时，loading 值为 false
+  loading
+  // highlight-end
+} = useWatcher(
+  () => getTodoList($currentPage),
+  // 被监听的状态数组，这些状态变化将会触发一次请求
+  [state],
+  {
+    sendable: methodInstance => {
+      // do something
+      // 仅当 state 为 1 时发送请求
+      return state === 1;
+    }
+  }
+);
+```
 
 ## API
 
@@ -575,6 +601,7 @@ const alovaInst = createAlova({
 | managedStates | 额外的监管状态，可通过 updateState 更新                                    | Record<string | number | symbol, any>                                                                                                                                 | -        | -    |
 | debounce      | 请求防抖时间（毫秒），传入数组时可按 watchingStates 的顺序单独设置防抖时间 | number                                                                                                                                                                                | number[] | -    | -   |
 | middleware    | 中间件函数，[了解 alova 中间件](../advanced/middleware)                    | (context: [AlovaFrontMiddlewareContext](../learning/use-request/#alovafrontmiddlewarecontext), next: [AlovaGuardNext](../learning/use-request/#alovaguardnext)) => Promise<any> | -        | -    |
+| sendable         | 监听的状态改变时是否发送请求                              | (methodInstance: AlovaEvent) => boolean                                                                                                                                            | () => true  | -    |
 
 ### 响应式数据