feat: add component watchParam

content/en/docs/3.features/4.data-fetching.md

@@ -272,3 +272,11 @@ The `asyncData` method is not called on query string changes by default. If
 ::alert{type="next"}
 Learn more about the [watchQuery property](/docs/components-glossary/watchquery) and see the list of available [keys in context](/docs/concepts/context-helpers).
 ::
+
+### Listening to param changes
+
+By default every route param change will call `asyncData`. If you want to disable it, set up `watchParam: false`. For example it may be helpfull to disable `state` reset. 
+
+::alert{type="next"}
+Learn more about the [watchParam property](/docs/components-glossary/watchparam).
+::

content/en/docs/7.components-glossary/11.watchparam.md

@@ -0,0 +1,31 @@
+---
+title: 'The watchParam Property'
+description: Watch param change and execute component methods on change (asyncData, fetch(context))
+navigation.title: WatchParam Property
+category: components-glossary
+---
+# The watchParam property
+
+Watch param change and execute component methods on change (asyncData, fetch(context))
+
+---
+
+- **Type:** `Boolean` (default: `undefined`)
+
+Use the `watchParam` key to set up a watcher for route params. If the params change, asyncData and fetch(context) will be called. Watching is enabled by default.
+
+If you want to disable watching for params, set `watchParam: false`.
+
+```js
+export default {
+  watchParam: false
+}
+```
+
+::alert{type="info"}
+By default `nuxt.js` reset _page_ component `data` state after route param change, you can use `watchParam: false` to disable this behaviour.
+::
+
+::alert{type="warning"}
+**Warning**: The new `fetch` hook introduced in 2.12 is not affected by `watchParam`. For more information see [listening to query string changes](/docs/features/data-fetching#the-fetch-hook) for params is the same.
+::