From 8a8d673944674f3dd390634f87c2a03e37c7b6d2 Mon Sep 17 00:00:00 2001
From: Chau Tran <nartc7789@gmail.com>
Date: Sun, 14 Mar 2021 16:48:52 -0500
Subject: [PATCH] docs: add docs about MapPipe

---
 docs-site/docs/nestjs.md | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/docs-site/docs/nestjs.md b/docs-site/docs/nestjs.md
index a26fac74e..c90b43b81 100644
--- a/docs-site/docs/nestjs.md
+++ b/docs-site/docs/nestjs.md
@@ -181,7 +181,40 @@ export class UserController {
 MapInterceptor(destinationModelType, sourceModelType, {
   isArray?: boolean;
   mapperName?: string;
-} & MapAction)
+} & MapOptions)
 ```
 
-> See [MapAction](misc/callbacks.md)
+> See [MapOptions](misc/callbacks.md)
+
+## `MapPipe`
+
+`@automapper/nestjs` provides `MapPipe`. When you want to transform the incoming request body before it gets to the route handler, you can utilize `MapPipe` to achieve this behavior
+
+```ts
+@Post('/from-body')
+postFromBody(@Body(MapPipe(UserDto, User)) user: UserDto) {
+    // from the request perspective, user coming in as an User object but will be mapped to UserDto with MapPipe
+    return user;
+}
+```
+
+`MapPipe` only works with `@Body` or `@Query`.
+
+```ts
+@Get('/from-query')
+getFromQuery(@Query(MapPipe(UserDto, User)) user: UserDto) {
+    // from the request perspective, user coming in as an User object but will be mapped to UserDto with MapPipe
+    return user;
+}
+```
+
+> Note that when you send a request with `Body` or `Query`, the data is serialized. Data-type like `Date` will come in the request handler as `string`. Hence, please be cautious of the mapping configuration when you use `MapPipe`
+
+`MapPipe` has the same signature as `MapInterceptor`
+
+```ts
+MapPipe(destinationModelType, sourceModelType, {
+  isArray?: boolean;
+  mapperName?: string;
+} & MapOptions)
+```