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phoenix
1.1.1
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1.8.8
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1.3.5
1.3.4
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1.3.1
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1.3.0-rc.2
1.3.0-rc.1
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1.2.4
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1.1.9
1.1.8
1.1.7
1.1.6
1.1.5
1.1.4
1.1.3
1.1.2
1.1.1
1.1.0
1.0.6
1.0.5
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1.0.1
1.0.0
0.17.1
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0.16.1
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0.13.1
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0.9.0
0.8.0
0.7.2
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0.2.7
0.2.6
0.2.5
0.2.4
0.2.3
0.2.2
0.2.1
0.2.0
0.1.0
Productive. Reliable. Fast. A productive web framework that does not compromise speed or maintainability.
Security advisory:
This version has known vulnerabilities.
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Files
lib/phoenix/controller/pipeline.ex
defmodule Phoenix.Controller.Pipeline do
@moduledoc """
This module implements the controller pipeline responsible for handling requests.
## The pipeline
The goal of a controller is to receive a request and invoke the desired
action. The whole flow of the controller is managed by a single pipeline:
defmodule UserController do
use Phoenix.Controller
require Logger
plug :log_message, "before action"
def show(conn, _params) do
Logger.debug "show/2"
send_resp(conn, 200, "OK")
end
defp log_message(conn, msg) do
Logger.debug msg
conn
end
end
When invoked, this pipeline will print:
before action
show/2
As any other Plug pipeline, we can halt at any step by calling
`Plug.Conn.halt/1` (which is by default imported into controllers).
If we change `log_message/2` to:
def log_message(conn, msg) do
Logger.debug msg
halt(conn)
end
it will print only:
before action
As the rest of the pipeline (the action and the after action plug)
will never be invoked.
## Guards
`plug/2` supports guards, allowing a developer to configure a plug to only
run in some particular action:
plug :log_message, "before show and edit" when action in [:show, :edit]
plug :log_message, "before all but index" when not action in [:index]
The first plug will run only when action is show or edit.
The second plug will always run, except for the index action.
Those guards work like regular Elixir guards and the only variables accessible
in the guard are `conn`, the `action` as an atom and the `controller` as an
alias.
## Controllers are plugs
Like routers, controllers are plugs, but they are wired to dispatch
to a particular function which is called an action.
For example, the route:
get "/users/:id", UserController, :show
will invoke `UserController` as a plug:
UserController.call(conn, :show)
which will trigger the plug pipeline and which will eventually
invoke the inner action plug that dispatches to the `show/2`
function in the `UserController`.
As controllers are plugs, they implement both `init/1` and
`call/2`, and it also provides a function named `action/2`
which is responsible for dispatching the appropriate action
after the plug stack (and is also overridable).
"""
@doc false
defmacro __using__(_) do
quote do
@behaviour Plug
require Phoenix.Endpoint
import Phoenix.Controller.Pipeline
Module.register_attribute(__MODULE__, :plugs, accumulate: true)
@before_compile Phoenix.Controller.Pipeline
@doc false
def init(action) when is_atom(action) do
action
end
@doc false
def call(conn, action) do
conn = update_in conn.private,
&(&1 |> Map.put(:phoenix_controller, __MODULE__)
|> Map.put(:phoenix_action, action))
Phoenix.Endpoint.instrument conn, :phoenix_controller_call, fn ->
phoenix_controller_pipeline(conn, action)
end
end
@doc false
def action(%{private: %{phoenix_action: action}} = conn, _options) do
apply(__MODULE__, action, [conn, conn.params])
end
defoverridable [init: 1, call: 2, action: 2]
end
end
@doc false
defmacro __before_compile__(env) do
action = {:action, [], true}
plugs = [action|Module.get_attribute(env.module, :plugs)]
{conn, body} = Plug.Builder.compile(env, plugs, log_on_halt: :debug)
quote do
defoverridable [action: 2]
def action(conn, opts) do
try do
super(conn, opts)
catch
kind, reason ->
Phoenix.Controller.Pipeline.__catch__(
kind, reason, __MODULE__, conn.private.phoenix_action, System.stacktrace
)
end
end
defp phoenix_controller_pipeline(unquote(conn), var!(action)) do
var!(conn) = unquote(conn)
var!(controller) = __MODULE__
_ = var!(conn)
_ = var!(controller)
_ = var!(action)
unquote(body)
end
end
end
@doc false
def __catch__(:error, :function_clause, controller, action,
[{controller, action, [%Plug.Conn{} | _], _loc} | _] = stack) do
args = [controller: controller, action: action]
reraise Phoenix.ActionClauseError, args, stack
end
def __catch__(kind, reason, _controller, _action, stack) do
:erlang.raise(kind, reason, stack)
end
@doc """
Stores a plug to be executed as part of the plug pipeline.
"""
defmacro plug(plug)
defmacro plug({:when, _, [plug, guards]}), do:
plug(plug, [], guards)
defmacro plug(plug), do:
plug(plug, [], true)
@doc """
Stores a plug with the given options to be executed as part of
the plug pipeline.
"""
defmacro plug(plug, opts)
defmacro plug(plug, {:when, _, [opts, guards]}), do:
plug(plug, opts, guards)
defmacro plug(plug, opts), do:
plug(plug, opts, true)
defp plug(plug, opts, guards) do
quote do
@plugs {unquote(plug), unquote(opts), unquote(Macro.escape(guards))}
end
end
end