Documentation: Request

docs/website/docs/v1.x/dsl/request/index.md

@@ -1 +1,91 @@
-# Work in progress
+# Request
+
+**ZIO HTTP** `Request` is designed in the simplest way possible to decode HTTP Request into a ZIO HTTP request.
+ It supports all HTTP request methods (as defined in [RFC2616](https://datatracker.ietf.org/doc/html/rfc2616) ) and headers along with custom methods and headers.
+
+## Creating a Request
+
+`Request` can be created with `method`, `url`, `headers`, `remoteAddress` and `data`. 
+Creating requests using `Request` is useful while writing unit tests.
+
+The below snippet creates a request with default params, `method` as `Method.GET`, `url` as `URL.root`, `headers` as `Headers.empty`, `data` as `HttpData.Empty`, `remoteAddress` as `None`
+```scala
+val request: Request = Request()
+```
+
+## Matching and Extracting Requests
+
+`Request` can be extracted into an HTTP Method and Path via `->`. On the left side is the `Method`, and on the right side, the `Path`.
+
+```scala
+Method.GET -> !! / "text"
+```
+### Method
+ `Method` represents HTTP methods like POST, GET, PUT, PATCH, and DELETE.
+You can create existing HTTP methods such as `Method.GET`, `Method.POST` etc or create a custom one.
+
+
+### Path
+ `Path` can be created using
+  - `!!` which represents the root
+  - `/` which represents the path delimiter and starts the extraction from the left-hand side of the expression
+  - `/:` which represents the path delimiter and starts the extraction from the right-hand side of the expression and can match paths partially 
+
+The below snippet creates an `HttpApp` that accepts an input of type `Request` and output of type `Response` with two paths.
+According to the request path, it will respond with the corresponding response:
+- if the request has path `/name` it will match the first route.
+- if the request has path `/name/joe/wilson` it will match the second route as `/:` matches the path partially as well.  
+
+ ```scala
+  val app: HttpApp[Any, Nothing] = Http.collect[Request] {
+     case Method.GET -> !! / a => Response.text(s"$a")
+     case Method.GET -> "name" /: a => Response.text(s"$a")
+   }
+```
+
+## Accessing the Request
+
+- `getBody` to access the content of request as a Chunk[Byte]
+```scala
+  val app = Http.collectZIO[Request] { case req => req.getBody.as(Response.ok) }
+``` 
+- `getBodyAsString` to access the content of request as string
+```scala
+  val app = Http.collectZIO[Request] { case req => req.getBodyAsString.as(Response.ok) }
+``` 
+- `getHeaders` to get all the headers in the Request
+```scala
+  val app = Http.collect[Request] { case req => Response.text(req.getHeaders.toList.mkString("")) }
+```
+- `method` to access request method
+```scala
+val app = Http.collect[Request] { case req => Response.text(req.method.toString())}
+```
+- `path` to access request path
+```scala
+  val app = Http.collect[Request] { case req => Response.text(req.path.toString())}
+```
+- `remoteAddress` to access request's remote address if available
+```scala
+  val app = Http.collect[Request] { case req => Response.text(req.remoteAddress.toString())}
+```
+- `url` to access the complete url
+```scala
+  val app = Http.collect[Request] { case req => Response.text(req.url.toString())}
+```
+
+## Creating and reading a Request with query params
+
+Query params can be added in the request using `url` in `Request`, `URL` stores query params as `Map[String, List[String]]`.
+
+The below snippet creates a request with query params: `?q=a&q=b&q=c` 
+```scala
+      val request: Request = Request(url = URL(!!, queryParams = Map("q" -> List("a","b","c"))))
+```
+
+`url.queryParams` can be used to read query params from the request
+
+The below snippet shows how to read query params from request
+```scala
+  val app = Http.collect[Request] { case req => Response.text(req.url.queryParams.mkString(""))}
+```