/
conn.ex
1501 lines (1206 loc) · 49.4 KB
/
conn.ex
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alias Plug.Conn.Unfetched
defmodule Plug.Conn do
@moduledoc """
The Plug connection.
This module defines a `Plug.Conn` struct and the main functions
for working with Plug connections.
Note request headers are normalized to lowercase and response
headers are expected to have lower-case keys.
## Request fields
These fields contain request information:
* `host` - the requested host as a binary, example: `"www.example.com"`
* `method` - the request method as a binary, example: `"GET"`
* `path_info` - the path split into segments, example: `["hello", "world"]`
* `script_name` - the initial portion of the URL's path that corresponds to
the application routing, as segments, example: ["sub","app"]
* `request_path` - the requested path, example: `/trailing/and//double//slashes/`
* `port` - the requested port as an integer, example: `80`
* `remote_ip` - the IP of the client, example: `{151, 236, 219, 228}`. This field
is meant to be overwritten by plugs that understand e.g. the `X-Forwarded-For`
header or HAProxy's PROXY protocol. It defaults to peer's IP
* `req_headers` - the request headers as a list, example: `[{"content-type", "text/plain"}]`.
Note all headers will be downcased
* `scheme` - the request scheme as an atom, example: `:http`
* `query_string` - the request query string as a binary, example: `"foo=bar"`
## Fetchable fields
The request information in these fields is not populated until it is fetched
using the associated `fetch_` function. For example, the `cookies` field uses
`fetch_cookies/2`.
If you access these fields before fetching them, they will be returned as
`Plug.Conn.Unfetched` structs.
* `cookies`- the request cookies with the response cookies
* `body_params` - the request body params, populated through a `Plug.Parsers` parser.
* `query_params` - the request query params, populated through `fetch_query_params/2`
* `path_params` - the request path params, populated by routers such as `Plug.Router`
* `params` - the request params, the result of merging the `:body_params` and
`:query_params` with `:path_params`
* `req_cookies` - the request cookies (without the response ones)
## Response fields
These fields contain response information:
* `resp_body` - the response body, by default is an empty string. It is set
to nil after the response is sent, except for test connections.
* `resp_charset` - the response charset, defaults to "utf-8"
* `resp_cookies` - the response cookies with their name and options
* `resp_headers` - the response headers as a list of tuples, by default `cache-control`
is set to `"max-age=0, private, must-revalidate"`. Note, response headers
are expected to have lower-case keys.
* `status` - the response status
Furthermore, the `before_send` field stores callbacks that are invoked
before the connection is sent. Callbacks are invoked in the reverse order
they are registered (callbacks registered first are invoked last) in order
to reproduce a pipeline ordering.
## Connection fields
* `assigns` - shared user data as a map
* `owner` - the Elixir process that owns the connection
* `halted` - the boolean status on whether the pipeline was halted
* `secret_key_base` - a secret key used to verify and encrypt cookies.
the field must be set manually whenever one of those features are used.
This data must be kept in the connection and never used directly, always
use `Plug.Crypto.KeyGenerator.generate/3` to derive keys from it
* `state` - the connection state
The connection state is used to track the connection lifecycle. It starts as
`:unset` but is changed to `:set` (via `resp/3`) or `:set_chunked`
(used only for `before_send` callbacks by `send_chunked/2`) or `:file`
(when invoked via `send_file/3`). Its final result is `:sent`, `:file` or
`:chunked` depending on the response model.
## Private fields
These fields are reserved for libraries/framework usage.
* `adapter` - holds the adapter information in a tuple
* `private` - shared library data as a map
## Custom status codes
Plug allows status codes to be overridden or added in order to allow new codes
not directly specified by Plug or its adapters. Adding or overriding a status
code is done through the Mix configuration of the `:plug` application. For
example, to override the existing 404 reason phrase for the 404 status code
("Not Found" by default) and add a new 451 status code, the following config
can be specified:
config :plug, :statuses, %{
404 => "Actually This Was Found",
451 => "Unavailable For Legal Reasons"
}
As this configuration is Plug specific, Plug will need to be recompiled for
the changes to take place: this will not happen automatically as dependencies
are not automatically recompiled when their configuration changes. To recompile
Plug:
mix deps.clean --build plug
The atoms that can be used in place of the status code in many functions are
inflected from the reason phrase of the status code. With the above
configuration, the following will all work:
put_status(conn, :not_found) # 404
put_status(conn, :actually_this_was_found) # 404
put_status(conn, :unavailable_for_legal_reasons) # 451
Even though 404 has been overridden, the `:not_found` atom can still be used
to set the status to 404 as well as the new atom `:actually_this_was_found`
inflected from the reason phrase "Actually This Was Found".
"""
@type adapter :: {module, term}
@type assigns :: %{atom => any}
@type before_send :: [(t -> t)]
@type body :: iodata
@type cookies :: %{binary => binary}
@type halted :: boolean
@type headers :: [{binary, binary}]
@type host :: binary
@type int_status :: non_neg_integer | nil
@type owner :: pid
@type method :: binary
@type param :: binary | %{binary => param} | [param]
@type params :: %{binary => param}
@type peer :: {:inet.ip_address(), :inet.port_number()}
@type port_number :: :inet.port_number()
@type query_string :: String.t()
@type resp_cookies :: %{binary => %{}}
@type scheme :: :http | :https
@type secret_key_base :: binary | nil
@type segments :: [binary]
@type state :: :unset | :set | :set_chunked | :set_file | :file | :chunked | :sent
@type status :: atom | int_status
@type t :: %__MODULE__{
adapter: adapter,
assigns: assigns,
before_send: before_send,
body_params: params | Unfetched.t(),
cookies: cookies | Unfetched.t(),
host: host,
method: method,
owner: owner,
params: params | Unfetched.t(),
path_info: segments,
path_params: params,
peer: peer,
port: :inet.port_number(),
private: assigns,
query_params: params | Unfetched.t(),
query_string: query_string,
remote_ip: :inet.ip_address(),
req_cookies: cookies | Unfetched.t(),
req_headers: headers,
request_path: binary,
resp_body: body | nil,
resp_cookies: resp_cookies,
resp_headers: headers,
scheme: scheme,
script_name: segments,
secret_key_base: secret_key_base,
state: state,
status: int_status
}
defstruct adapter: {Plug.MissingAdapter, nil},
assigns: %{},
before_send: [],
body_params: %Unfetched{aspect: :body_params},
cookies: %Unfetched{aspect: :cookies},
halted: false,
host: "www.example.com",
method: "GET",
owner: nil,
params: %Unfetched{aspect: :params},
path_params: %{},
path_info: [],
peer: nil,
port: 0,
private: %{},
query_params: %Unfetched{aspect: :query_params},
query_string: "",
remote_ip: nil,
req_cookies: %Unfetched{aspect: :cookies},
req_headers: [],
request_path: "",
resp_body: nil,
resp_cookies: %{},
resp_headers: [{"cache-control", "max-age=0, private, must-revalidate"}],
scheme: :http,
script_name: [],
secret_key_base: nil,
state: :unset,
status: nil
defmodule NotSentError do
defexception message: "a response was neither set nor sent from the connection"
@moduledoc """
Error raised when no response is sent in a request
"""
end
defmodule AlreadySentError do
defexception message: "the response was already sent"
@moduledoc """
Error raised when trying to modify or send an already sent response
"""
end
defmodule CookieOverflowError do
defexception message: "cookie exceeds maximum size of 4096 bytes"
@moduledoc """
Error raised when the cookie exceeds the maximum size of 4096 bytes.
"""
end
defmodule InvalidHeaderError do
defexception message: "header is invalid"
@moduledoc ~S"""
Error raised when trying to send a header that has errors, for example:
* the header key contains uppercase chars
* the header value contains newlines \n
"""
end
defmodule InvalidQueryError do
@moduledoc """
Raised when the request string is malformed, for example:
* the query has bad utf-8 encoding
* the query fails to www-form decode
"""
defexception message: "query string is invalid", plug_status: 400
end
alias Plug.Conn
@already_sent {:plug_conn, :sent}
@unsent [:unset, :set, :set_chunked, :set_file]
@doc """
Assigns a value to a key in the connection.
## Examples
iex> conn.assigns[:hello]
nil
iex> conn = assign(conn, :hello, :world)
iex> conn.assigns[:hello]
:world
"""
@spec assign(t, atom, term) :: t
def assign(%Conn{assigns: assigns} = conn, key, value) when is_atom(key) do
%{conn | assigns: Map.put(assigns, key, value)}
end
@doc """
Assigns multiple values to keys in the connection.
Equivalent to multiple calls to `assign/3`.
## Examples
iex> conn.assigns[:hello]
nil
iex> conn = merge_assigns(conn, hello: :world)
iex> conn.assigns[:hello]
:world
"""
@spec merge_assigns(t, Keyword.t()) :: t
def merge_assigns(%Conn{assigns: assigns} = conn, keyword) when is_list(keyword) do
%{conn | assigns: Enum.into(keyword, assigns)}
end
@doc false
@spec async_assign(t, atom, (() -> term)) :: t
def async_assign(%Conn{} = conn, key, fun) when is_atom(key) and is_function(fun, 0) do
IO.warn("Plug.Conn.async_assign/3 is deprecated, please call assign + Task.async instead")
assign(conn, key, Task.async(fun))
end
@doc false
@spec await_assign(t, atom, timeout) :: t
def await_assign(%Conn{} = conn, key, timeout \\ 5000) when is_atom(key) do
IO.warn(
"Plug.Conn.await_assign/3 is deprecated, please fetch the assign and call Task.await instead"
)
task = Map.fetch!(conn.assigns, key)
assign(conn, key, Task.await(task, timeout))
end
@doc """
Assigns a new **private** key and value in the connection.
This storage is meant to be used by libraries and frameworks to avoid writing
to the user storage (the `:assigns` field). It is recommended for
libraries/frameworks to prefix the keys with the library name.
For example, if some plug needs to store a `:hello` key, it
should do so as `:plug_hello`:
iex> conn.private[:plug_hello]
nil
iex> conn = put_private(conn, :plug_hello, :world)
iex> conn.private[:plug_hello]
:world
"""
@spec put_private(t, atom, term) :: t
def put_private(%Conn{private: private} = conn, key, value) when is_atom(key) do
%{conn | private: Map.put(private, key, value)}
end
@doc """
Assigns multiple **private** keys and values in the connection.
Equivalent to multiple `put_private/3` calls.
## Examples
iex> conn.private[:plug_hello]
nil
iex> conn = merge_private(conn, plug_hello: :world)
iex> conn.private[:plug_hello]
:world
"""
@spec merge_private(t, Keyword.t()) :: t
def merge_private(%Conn{private: private} = conn, keyword) when is_list(keyword) do
%{conn | private: Enum.into(keyword, private)}
end
@doc """
Stores the given status code in the connection.
The status code can be `nil`, an integer or an atom. The list of allowed
atoms is available in `Plug.Conn.Status`.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
"""
@spec put_status(t, status) :: t
def put_status(%Conn{state: :sent}, _status), do: raise(AlreadySentError)
def put_status(%Conn{} = conn, nil), do: %{conn | status: nil}
def put_status(%Conn{} = conn, status), do: %{conn | status: Plug.Conn.Status.code(status)}
@doc """
Sends a response to the client.
It expects the connection state to be `:set`, otherwise raises an
`ArgumentError` for `:unset` connections or a `Plug.Conn.AlreadySentError` for
already `:sent` connections.
At the end sets the connection state to `:sent`.
"""
@spec send_resp(t) :: t | no_return
def send_resp(conn)
def send_resp(%Conn{state: :unset}) do
raise ArgumentError, "cannot send a response that was not set"
end
def send_resp(%Conn{adapter: {adapter, payload}, state: :set, owner: owner} = conn) do
conn = run_before_send(conn, :set)
{:ok, body, payload} =
adapter.send_resp(payload, conn.status, conn.resp_headers, conn.resp_body)
send(owner, @already_sent)
%{conn | adapter: {adapter, payload}, resp_body: body, state: :sent}
end
def send_resp(%Conn{}) do
raise AlreadySentError
end
@doc """
Sends a file as the response body with the given `status`
and optionally starting at the given offset until the given length.
If available, the file is sent directly over the socket using
the operating system `sendfile` operation.
It expects a connection that has not been `:sent` yet and sets its
state to `:file` afterwards. Otherwise raises `Plug.Conn.AlreadySentError`.
## Examples
Plug.Conn.send_file(conn, 200, "README.md")
"""
@spec send_file(t, status, filename :: binary, offset :: integer, length :: integer | :all) ::
t | no_return
def send_file(conn, status, file, offset \\ 0, length \\ :all)
def send_file(%Conn{state: state}, status, _file, _offset, _length)
when not (state in @unsent) do
_ = Plug.Conn.Status.code(status)
raise AlreadySentError
end
def send_file(
%Conn{adapter: {adapter, payload}, owner: owner} = conn,
status,
file,
offset,
length
)
when is_binary(file) do
if file =~ "\0" do
raise ArgumentError, "cannot send_file/5 with null byte"
end
conn =
run_before_send(%{conn | status: Plug.Conn.Status.code(status), resp_body: nil}, :set_file)
{:ok, body, payload} =
adapter.send_file(payload, conn.status, conn.resp_headers, file, offset, length)
send(owner, @already_sent)
%{conn | adapter: {adapter, payload}, state: :file, resp_body: body}
end
@doc """
Sends the response headers as a chunked response.
It expects a connection that has not been `:sent` yet and sets its
state to `:chunked` afterwards. Otherwise raises `Plug.Conn.AlreadySentError`.
"""
@spec send_chunked(t, status) :: t | no_return
def send_chunked(%Conn{state: state}, status)
when not (state in @unsent) do
_ = Plug.Conn.Status.code(status)
raise AlreadySentError
end
def send_chunked(%Conn{adapter: {adapter, payload}, owner: owner} = conn, status) do
conn = %{conn | status: Plug.Conn.Status.code(status), resp_body: nil}
conn = run_before_send(conn, :set_chunked)
{:ok, body, payload} = adapter.send_chunked(payload, conn.status, conn.resp_headers)
send(owner, @already_sent)
%{conn | adapter: {adapter, payload}, state: :chunked, resp_body: body}
end
@doc """
Sends a chunk as part of a chunked response.
It expects a connection with state `:chunked` as set by
`send_chunked/2`. It returns `{:ok, conn}` in case of success,
otherwise `{:error, reason}`.
To stream data use `Enum.reduce_while/3` instead of `Enum.into/2`.
`Enum.reduce_while/3` allows aborting the execution if `chunk/2` fails to
deliver the chunk of data.
## Example
~w(each chunk as a word)
|> Enum.reduce_while(conn, fn (chunk, conn) ->
case Plug.Conn.chunk(conn, chunk) do
{:ok, conn} ->
{:cont, conn}
{:error, :closed} ->
{:halt, conn}
end
end)
"""
@spec chunk(t, body) :: {:ok, t} | {:error, term} | no_return
def chunk(%Conn{adapter: {adapter, payload}, state: :chunked} = conn, chunk) do
if iodata_empty?(chunk) do
{:ok, conn}
else
case adapter.chunk(payload, chunk) do
:ok -> {:ok, conn}
{:ok, body, payload} -> {:ok, %{conn | resp_body: body, adapter: {adapter, payload}}}
{:error, _} = error -> error
end
end
end
def chunk(%Conn{}, chunk) when is_binary(chunk) or is_list(chunk) do
raise ArgumentError,
"chunk/2 expects a chunked response. Please ensure " <>
"you have called send_chunked/2 before you send a chunk"
end
defp iodata_empty?(""), do: true
defp iodata_empty?([]), do: true
defp iodata_empty?([head | tail]), do: iodata_empty?(head) and iodata_empty?(tail)
defp iodata_empty?(_), do: false
@doc """
Sends a response with the given status and body.
See `send_resp/1` for more information.
"""
@spec send_resp(t, status, body) :: t | no_return
def send_resp(%Conn{} = conn, status, body) do
conn |> resp(status, body) |> send_resp()
end
@doc """
Sets the response to the given `status` and `body`.
It sets the connection state to `:set` (if not already `:set`)
and raises `Plug.Conn.AlreadySentError` if it was already `:sent`.
"""
@spec resp(t, status, body) :: t
def resp(%Conn{state: state}, status, _body)
when not (state in @unsent) do
_ = Plug.Conn.Status.code(status)
raise AlreadySentError
end
def resp(%Conn{}, _status, nil) do
raise ArgumentError, "response body cannot be set to nil"
end
def resp(%Conn{} = conn, status, body)
when is_binary(body) or is_list(body) do
%{conn | status: Plug.Conn.Status.code(status), resp_body: body, state: :set}
end
@doc """
Returns the request peer data if one is present.
"""
@spec get_peer_data(t) :: Plug.Conn.Adapter.peer_data()
def get_peer_data(%Conn{adapter: {adapter, payload}}) do
adapter.get_peer_data(payload)
end
@doc """
Returns the http protocol and version.
"""
@spec get_http_protocol(t) :: Plug.Conn.Adapter.http_protocol()
def get_http_protocol(%Conn{adapter: {adapter, payload}}) do
adapter.get_http_protocol(payload)
end
@doc """
Returns the values of the request header specified by `key`.
"""
@spec get_req_header(t, binary) :: [binary]
def get_req_header(%Conn{req_headers: headers}, key) when is_binary(key) do
for {k, v} <- headers, k == key, do: v
end
@doc """
Adds a new request header (`key`) if not present, otherwise replaces the
previous value of that header with `value`.
It is recommended for header keys to be in lower-case, to avoid sending
duplicate keys in a request. As a convenience, this is validated during
testing which raises a `Plug.Conn.InvalidHeaderError` if the header key
is not lowercase.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
"""
@spec put_req_header(t, binary, binary) :: t
def put_req_header(%Conn{state: :sent}, _key, _value) do
raise AlreadySentError
end
def put_req_header(%Conn{adapter: adapter, req_headers: headers} = conn, key, value)
when is_binary(key) and is_binary(value) do
validate_header_key_if_test!(adapter, key)
%{conn | req_headers: List.keystore(headers, key, 0, {key, value})}
end
@doc """
Deletes a request header if present.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
"""
@spec delete_req_header(t, binary) :: t
def delete_req_header(%Conn{state: :sent}, _key) do
raise AlreadySentError
end
def delete_req_header(%Conn{state: :chunked}, _key) do
raise AlreadySentError
end
def delete_req_header(%Conn{req_headers: headers} = conn, key)
when is_binary(key) do
%{conn | req_headers: List.keydelete(headers, key, 0)}
end
@doc """
Updates a request header if present, otherwise it sets it to an initial
value.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
"""
@spec update_req_header(t, binary, binary, (binary -> binary)) :: t
def update_req_header(%Conn{state: :sent}, _key, _initial, _fun) do
raise AlreadySentError
end
def update_req_header(%Conn{state: :chunked}, _key, _initial, _fun) do
raise AlreadySentError
end
def update_req_header(%Conn{} = conn, key, initial, fun)
when is_binary(key) and is_binary(initial) and is_function(fun, 1) do
case get_req_header(conn, key) do
[] -> put_req_header(conn, key, initial)
[current | _] -> put_req_header(conn, key, fun.(current))
end
end
@doc """
Returns the values of the response header specified by `key`.
## Examples
iex> conn = %{conn | resp_headers: [{"content-type", "text/plain"}]}
iex> get_resp_header(conn, "content-type")
["text/plain"]
"""
@spec get_resp_header(t, binary) :: [binary]
def get_resp_header(%Conn{resp_headers: headers}, key) when is_binary(key) do
for {k, v} <- headers, k == key, do: v
end
@doc ~S"""
Adds a new response header (`key`) if not present, otherwise replaces the
previous value of that header with `value`.
It is recommended for header keys to be in lower-case, to avoid sending
duplicate keys in a request. As a convenience, this is validated during
testing which raises a `Plug.Conn.InvalidHeaderError` if the header key
is not lowercase.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
Raises a `Plug.Conn.InvalidHeaderError` if the header value contains control
feed (`\r`) or newline (`\n`) characters.
"""
@spec put_resp_header(t, binary, binary) :: t
def put_resp_header(%Conn{state: :sent}, _key, _value) do
raise AlreadySentError
end
def put_resp_header(%Conn{state: :chunked}, _key, _value) do
raise AlreadySentError
end
def put_resp_header(%Conn{adapter: adapter, resp_headers: headers} = conn, key, value)
when is_binary(key) and is_binary(value) do
validate_header_key_if_test!(adapter, key)
validate_header_value!(key, value)
%{conn | resp_headers: List.keystore(headers, key, 0, {key, value})}
end
@doc ~S"""
Prepends the list of headers to the connection response headers.
Similar to `put_resp_header` this functions adds a new response header
(`key`) but rather then replacing the existing one it prepends another header
with the same `key`.
It is recommended for header keys to be in lower-case, to avoid sending
duplicate keys in a request. As a convenience, this is validated during
testing which raises a `Plug.Conn.InvalidHeaderError` if the header key
is not lowercase.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
Raises a `Plug.Conn.InvalidHeaderError` if the header value contains control
feed (`\r`) or newline (`\n`) characters.
"""
@spec prepend_resp_headers(t, headers) :: t
def prepend_resp_headers(%Conn{state: :sent}, _headers) do
raise AlreadySentError
end
def prepend_resp_headers(%Conn{state: :chunked}, _headers) do
raise AlreadySentError
end
def prepend_resp_headers(%Conn{adapter: adapter, resp_headers: resp_headers} = conn, headers)
when is_list(headers) do
for {key, value} <- headers do
validate_header_key_if_test!(adapter, key)
validate_header_value!(key, value)
end
%{conn | resp_headers: headers ++ resp_headers}
end
@doc """
Merges a series of response headers into the connection.
## Example
iex> conn = merge_resp_headers(conn, [{"content-type", "text/plain"}, {"X-1337", "5P34K"}])
"""
@spec merge_resp_headers(t, Enum.t()) :: t
def merge_resp_headers(%Conn{state: :sent}, _headers) do
raise AlreadySentError
end
def merge_resp_headers(%Conn{state: :chunked}, _headers) do
raise AlreadySentError
end
def merge_resp_headers(conn, headers) when headers == %{} do
conn
end
def merge_resp_headers(%Conn{resp_headers: current, adapter: adapter} = conn, headers) do
headers =
Enum.reduce(headers, current, fn {key, value}, acc
when is_binary(key) and is_binary(value) ->
validate_header_key_if_test!(adapter, key)
validate_header_value!(key, value)
List.keystore(acc, key, 0, {key, value})
end)
%{conn | resp_headers: headers}
end
@doc """
Deletes a response header if present.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
"""
@spec delete_resp_header(t, binary) :: t
def delete_resp_header(%Conn{state: :sent}, _key) do
raise AlreadySentError
end
def delete_resp_header(%Conn{state: :chunked}, _key) do
raise AlreadySentError
end
def delete_resp_header(%Conn{resp_headers: headers} = conn, key)
when is_binary(key) do
%{conn | resp_headers: List.keydelete(headers, key, 0)}
end
@doc """
Updates a response header if present, otherwise it sets it to an initial
value.
Raises a `Plug.Conn.AlreadySentError` if the connection has already been
`:sent` or `:chunked`.
"""
@spec update_resp_header(t, binary, binary, (binary -> binary)) :: t
def update_resp_header(%Conn{state: :sent}, _key, _initial, _fun) do
raise AlreadySentError
end
def update_resp_header(%Conn{state: :chunked}, _key, _initial, _fun) do
raise AlreadySentError
end
def update_resp_header(%Conn{} = conn, key, initial, fun)
when is_binary(key) and is_binary(initial) and is_function(fun, 1) do
case get_resp_header(conn, key) do
[] -> put_resp_header(conn, key, initial)
[current | _] -> put_resp_header(conn, key, fun.(current))
end
end
@doc """
Sets the value of the `"content-type"` response header taking into account the
`charset`.
"""
@spec put_resp_content_type(t, binary, binary | nil) :: t
def put_resp_content_type(conn, content_type, charset \\ "utf-8")
def put_resp_content_type(conn, content_type, nil) when is_binary(content_type) do
put_resp_header(conn, "content-type", content_type)
end
def put_resp_content_type(conn, content_type, charset)
when is_binary(content_type) and is_binary(charset) do
put_resp_header(conn, "content-type", "#{content_type}; charset=#{charset}")
end
@doc """
Fetches query parameters from the query string.
Params are decoded as "x-www-form-urlencoded" in which key/value pairs
are separated by `&` and keys are separated from values by `=`.
This function does not fetch parameters from the body. To fetch
parameters from the body, use the `Plug.Parsers` plug.
## Options
* `:length` - the maximum query string length. Defaults to 1_000_000 bytes.
"""
@spec fetch_query_params(t, Keyword.t()) :: t
def fetch_query_params(conn, opts \\ [])
def fetch_query_params(%Conn{query_params: %Unfetched{}} = conn, opts) do
%{params: params, query_string: query_string} = conn
Plug.Conn.Utils.validate_utf8!(query_string, InvalidQueryError, "query string")
length = Keyword.get(opts, :length, 1_000_000)
if byte_size(query_string) > length do
raise InvalidQueryError,
"maximum query string length is #{length}, got a query with #{byte_size(query_string)} bytes"
end
query_params = Plug.Conn.Query.decode(query_string)
case params do
%Unfetched{} -> %{conn | query_params: query_params, params: query_params}
%{} -> %{conn | query_params: query_params, params: Map.merge(query_params, params)}
end
end
def fetch_query_params(%Conn{} = conn, _opts) do
conn
end
@doc """
Reads the request body.
This function reads a chunk of the request body up to a given `:length`. If
there is more data to be read, then `{:more, partial_body, conn}` is
returned. Otherwise `{:ok, body, conn}` is returned. In case of an error
reading the socket, `{:error, reason}` is returned as per `:gen_tcp.recv/2`.
Like all functions in this module, the `conn` returned by `read_body` must
be passed to the next stage of your pipeline and should not be ignored.
In order to, for instance, support slower clients you can tune the
`:read_length` and `:read_timeout` options. These specify how much time should
be allowed to pass for each read from the underlying socket.
Because the request body can be of any size, reading the body will only
work once, as Plug will not cache the result of these operations. If you
need to access the body multiple times, it is your responsibility to store
it. Finally keep in mind some plugs like `Plug.Parsers` may read the body,
so the body may be unavailable after being accessed by such plugs.
This function is able to handle both chunked and identity transfer-encoding
by default.
## Options
* `:length` - sets the maximum number of bytes to read from the body on
every call, defaults to 8_000_000 bytes
* `:read_length` - sets the amount of bytes to read at one time from the
underlying socket to fill the chunk, defaults to 1_000_000 bytes
* `:read_timeout` - sets the timeout for each socket read, defaults to
15_000ms
The values above are not meant to be exact. For example, setting the
length to 8_000_000 may end up reading some hundred bytes more from
the socket until we halt.
## Examples
{:ok, body, conn} = Plug.Conn.read_body(conn, length: 1_000_000)
"""
@spec read_body(t, Keyword.t()) ::
{:ok, binary, t}
| {:more, binary, t}
| {:error, term}
def read_body(%Conn{adapter: {adapter, state}} = conn, opts \\ []) do
case adapter.read_req_body(state, opts) do
{:ok, data, state} ->
{:ok, data, %{conn | adapter: {adapter, state}}}
{:more, data, state} ->
{:more, data, %{conn | adapter: {adapter, state}}}
{:error, reason} ->
{:error, reason}
end
end
@doc """
Reads the headers of a multipart request.
It returns `{:ok, headers, conn}` with the headers or
`{:done, conn}` if there are no more parts.
Once `read_part_headers/2` is invoked, a developer may call
`read_part_body/2` to read the body associated to the headers.
If `read_part_headers/2` is called instead, the body is automatically
skipped until the next part headers.
## Options
* `:length` - sets the maximum number of bytes to read from the body for
each chunk, defaults to 64_000 bytes
* `:read_length` - sets the amount of bytes to read at one time from the
underlying socket to fill the chunk, defaults to 64_000 bytes
* `:read_timeout` - sets the timeout for each socket read, defaults to
5_000ms
"""
@spec read_part_headers(t, Keyword.t()) :: {:ok, headers, t} | {:done, t}
def read_part_headers(%Conn{adapter: {adapter, state}} = conn, opts \\ []) do
opts = opts ++ [length: 64_000, read_length: 64_000, read_timeout: 5000]
case init_multipart(conn) do
{boundary, buffer} ->
{data, state} = read_multipart_from_buffer_or_adapter(buffer, adapter, state, opts)
read_part_headers(conn, data, boundary, adapter, state, opts)
:done ->
{:done, conn}
end
end
defp read_part_headers(conn, data, boundary, adapter, state, opts) do
case :plug_multipart.parse_headers(data, boundary) do
{:ok, headers, rest} ->
{:ok, headers, store_multipart(conn, {boundary, rest}, adapter, state)}
:more ->
{_, next, state} = next_multipart(adapter, state, opts)
read_part_headers(conn, data <> next, boundary, adapter, state, opts)
{:more, rest} ->
{_, next, state} = next_multipart(adapter, state, opts)
read_part_headers(conn, rest <> next, boundary, adapter, state, opts)
{:done, _} ->
{:done, store_multipart(conn, :done, adapter, state)}
end
end
@doc """
Reads the body of a multipart request.
Returns `{:ok, body, conn}` if all body has been read,
`{:more, binary, conn}` otherwise, and `{:done, conn}`
if there is no more body.
It accepts the same options as `read_body/2`.
"""
@spec read_part_body(t, Keyword.t()) :: {:ok, binary, t} | {:more, binary, t} | {:done, t}
def read_part_body(%{adapter: {adapter, state}} = conn, opts) do
case init_multipart(conn) do
{boundary, buffer} ->
# Note we will read the whole length from the socket
# and then break it apart as necessary.
length = Keyword.get(opts, :length, 8_000_000)
{data, state} = read_multipart_from_buffer_or_adapter(buffer, adapter, state, opts)
read_part_body(conn, data, "", length, boundary, adapter, state, opts)
:done ->
{:done, conn}
end
end
defp read_part_body(conn, data, acc, length, boundary, adapter, state, _opts)
when byte_size(acc) > length do
{:more, acc, store_multipart(conn, {boundary, data}, adapter, state)}
end
defp read_part_body(conn, data, acc, length, boundary, adapter, state, opts) do
case :plug_multipart.parse_body(data, boundary) do
{:ok, body} ->
{_, next, state} = next_multipart(adapter, state, opts)
acc = prepend_unless_empty(acc, body)
read_part_body(conn, next, acc, length, boundary, adapter, state, opts)
{:ok, body, rest} ->
{_, next, state} = next_multipart(adapter, state, opts)
next = prepend_unless_empty(rest, next)