Plug

v1.8.0

Plug v1.8.0 Plug.Upload View Source

A server (a GenServer specifically) that manages uploaded files.

Uploaded files are stored in a temporary directory and removed from that directory after the process that requested the file dies.

During the request, files are represented with a Plug.Upload struct that contains three fields:

  • :path - the path to the uploaded file on the filesystem
  • :content_type - the content type of the uploaded file
  • :filename - the filename of the uploaded file given in the request

Note: as mentioned in the documentation for Plug.Parsers, the :plug application has to be started in order to upload files and use the Plug.Upload module.

Link to this section Summary

Types

t()

Functions

child_spec(init_arg)

Returns a specification to start this module under a supervisor

init(atom)

Invoked when the server is started. start_link/3 or start/3 will block until it returns

random_file(prefix)

Requests a random file to be created in the upload directory with the given prefix

random_file!(prefix)

Requests a random file to be created in the upload directory with the given prefix. Raises on failure

start_link()

Starts the upload handling server

Link to this section Types

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t() View Source 
t() :: %Plug.Upload{
  content_type: binary() | nil,
  filename: binary(),
  path: Path.t()
}

Link to this section Functions

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child_spec(init_arg) View Source

Returns a specification to start this module under a supervisor.

See Supervisor.

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init(atom) View Source

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

init_arg is the argument term (second argument) passed to start_link/3.

Returning {:ok, state} will cause start_link/3 to return {:ok, pid} and the process to enter its loop.

Returning {:ok, state, timeout} is similar to {:ok, state}, except that it also sets a timeout. See the "Timeouts" section in the module documentation for more information.

Returning {:ok, state, :hibernate} is similar to {:ok, state} except the process is hibernated before entering the loop. See c:handle_call/3 for more information on hibernation.

Returning {:ok, state, {:continue, continue}} is similar to {:ok, state} except that immediately after entering the loop the c:handle_continue/2 callback will be invoked with the value continue as first argument.

Returning :ignore will cause start_link/3 to return :ignore and the process will exit normally without entering the loop or calling c:terminate/2. If used when part of a supervision tree the parent supervisor will not fail to start nor immediately try to restart the GenServer. The remainder of the supervision tree will be started and so the GenServer should not be required by other processes. It can be started later with Supervisor.restart_child/2 as the child specification is saved in the parent supervisor. The main use cases for this are:

  • The GenServer is disabled by configuration but might be enabled later.
  • An error occurred and it will be handled by a different mechanism than the Supervisor. Likely this approach involves calling Supervisor.restart_child/2 after a delay to attempt a restart.

Returning {:stop, reason} will cause start_link/3 to return {:error, reason} and the process to exit with reason reason without entering the loop or calling c:terminate/2.

Callback implementation for GenServer.init/1.

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random_file(prefix) View Source 
random_file(binary()) ::
  {:ok, binary()}
  | {:too_many_attempts, binary(), pos_integer()}
  | {:no_tmp, [binary()]}

Requests a random file to be created in the upload directory with the given prefix.

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random_file!(prefix) View Source 
random_file!(binary()) :: binary() | no_return()

Requests a random file to be created in the upload directory with the given prefix. Raises on failure.

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start_link() View Source

Starts the upload handling server.