edit keep-alive

Author: yyx990803

src/api/index.md

@@ -1687,6 +1687,8 @@ type: api
 
   When wrapped around a dynamic component, `<keep-alive>` caches the inactive component instances without destroying them. Similar to `<transition>`, `<keep-alive>` is an abstract component: it doesn't render a DOM element itself, and doesn't show up in the component parent chain.
 
+  When a component is toggled inside `<keep-alive>`, its `activated` and `deactivated` lifecycle hooks will be invoked accordingly.
+
   Primarily used with preserve component state or avoid re-rendering.
 
   ```html
@@ -1709,6 +1711,8 @@ type: api
   </transition>
   ```
 
+  <p class="tip">`<keep-alive>` does not work with functional components because they do not have instances to be cached.</p>
+
 - **See also:** [Dynamic Components - keep-alive](/guide/components.html#keep-alive)
 
 ### slot

src/guide/components.md

@@ -843,7 +843,7 @@ new Vue({
 
 ### `keep-alive`
 
-If you want to keep the switched-out components in memory so that you can preserve their state or avoid re-rendering, you can wrap a dynamic component in a `keep-alive` element:
+If you want to keep the switched-out components in memory so that you can preserve their state or avoid re-rendering, you can wrap a dynamic component in a `<keep-alive>` element:
 
 ``` html
 <keep-alive>
@@ -853,6 +853,8 @@ If you want to keep the switched-out components in memory so that you can preser
 </keep-alive>
 ```
 
+Check out more details on `<keep-alive>` in the [API reference](/api/#keep-alive).
+
 ## Misc
 
 ### Authoring Reusable Components