ValidateQuery plug

A Plug that filters arbitrary query parameter keys.

Example

This plug was made primarily for JSON-API like usage in mind. With this spec, a couple of query parameters are expected, such as include, filter and sort:

defmodule MyApp.UserController do
  plug(ValidateQuery,
    include: {["company", "profile", :list]},
    filter: [name: {:any}, only_active: {:any, :boolean, true}],
  )

  def index(conn, _params) do
    # return response
  end
end

In the above example we filter two different query parameters: include and filter.

• include accepts a list where only company and profile are accepted as values.
• filter accepts a map with the keys name and only_active, of which name can be any value and only_active must be boolean. If none was given only_active will default to true.

The following url is an example of a (full) valid query according to the above spec:

/users?include=company,profile&filter[name]=john&filter[only_active]=false.

Which would results in conn.params like so:

%{
  "include" => ["company", "profile"],
  "filter" => %{"name" => "john", "only_active" => false}
}

Installation

If available in Hex, the package can be installed by adding plug_validate_query to your list of dependencies in mix.exs:

def deps do
  [
    {:plug_validate_query, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/plug_validate_query.