Plug

v1.8.0

Plug v1.8.0 Plug.Conn.Adapter behaviour View Source

Specification of the connection adapter API implemented by webservers

Link to this section Summary

Types

http_protocol()
payload()
peer_data()

Callbacks

chunk(payload, arg1)

Sends a chunk in the chunked response

get_http_protocol(payload)

Returns the HTTP protocol and its version

get_peer_data(payload)

Returns peer information such as the address, port and ssl cert

inform(payload, arg1, headers)

Send an informational response to the client

push(payload, path, headers)

Push a resource to the client

read_req_body(payload, options)

Reads the request body

send_chunked(payload, arg1, arg2)

Sends the given status, headers as the beginning of a chunked response to the client

send_file(payload, arg1, arg2, file, offset, length)

Sends the given status, headers and file as a response back to the client

send_resp(payload, arg1, arg2, arg3)

Sends the given status, headers and body as a response back to the client

Link to this section Types

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http_protocol() View Source 
http_protocol() :: :"HTTP/1" | :"HTTP/1.1" | :"HTTP/2" | atom()

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payload() View Source 
payload() :: term()

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peer_data() View Source 
peer_data() :: %{
  address: :inet.ip_address(),
  port: :inet.port_number(),
  ssl_cert: binary() | nil
}

Link to this section Callbacks

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chunk(payload, arg1) View Source 
chunk(payload(), Plug.Conn.status()) ::
  :ok | {:ok, sent_body :: binary(), payload()} | {:error, term()}

Sends a chunk in the chunked response.

If the request has method "HEAD", the adapter should not send the response to the client.

Webservers are advised to return :ok and not modify any further state for each chunk. However, the test implementation returns the actual body and payload so it can be used during testing.

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get_http_protocol(payload) View Source 
get_http_protocol(payload()) :: http_protocol()

Returns the HTTP protocol and its version.

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get_peer_data(payload) View Source 
get_peer_data(payload()) :: peer_data()

Returns peer information such as the address, port and ssl cert.

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inform(payload, arg1, headers) View Source 
inform(payload(), Plug.Conn.status(), headers :: Keyword.t()) ::
  :ok | {:error, term()}

Send an informational response to the client.

If the adapter does not support inform, then {:error, :not_supported} should be returned.

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push(payload, path, headers) View Source 
push(payload(), path :: String.t(), headers :: Keyword.t()) ::
  :ok | {:error, term()}

Push a resource to the client.

If the adapter does not support server push then {:error, :not_supported} should be returned.

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read_req_body(payload, options) View Source 
read_req_body(payload(), options :: Keyword.t()) ::
  {:ok, data :: binary(), payload()}
  | {:more, data :: binary(), payload()}
  | {:error, term()}

Reads the request body.

Read the docs in Plug.Conn.read_body/2 for the supported options and expected behaviour.

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send_chunked(payload, arg1, arg2) View Source 
send_chunked(payload(), Plug.Conn.status(), Plug.Conn.headers()) ::
  {:ok, sent_body :: binary() | nil, payload()}

Sends the given status, headers as the beginning of a chunked response to the client.

Webservers are advised to return nil as the sent_body, as the body can no longer be manipulated. However, the test implementation returns the actual body so it can be used during testing.

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send_file(payload, arg1, arg2, file, offset, length) View Source 
send_file(
  payload(),
  Plug.Conn.status(),
  Plug.Conn.headers(),
  file :: binary(),
  offset :: integer(),
  length :: integer() | :all
) :: {:ok, sent_body :: binary() | nil, payload()}

Sends the given status, headers and file as a response back to the client.

If the request has method "HEAD", the adapter should not send the response to the client.

Webservers are advised to return nil as the sent_body, as the body can no longer be manipulated. However, the test implementation returns the actual body so it can be used during testing.

Link to this callback

send_resp(payload, arg1, arg2, arg3) View Source 
send_resp(payload(), Plug.Conn.status(), Plug.Conn.headers(), Plug.Conn.body()) ::
  {:ok, sent_body :: binary() | nil, payload()}

Sends the given status, headers and body as a response back to the client.

If the request has method "HEAD", the adapter should not send the response to the client.

Webservers are advised to return nil as the sent_body, as the body can no longer be manipulated. However, the test implementation returns the actual body so it can be used during testing.