Arc.Ecto provides an integration with Arc and Ecto.
Add the latest stable release to your mix.exs
file:
defp deps do
[
{:arc_ecto, "~> 0.11.3"}
]
end
Then run mix deps.get
in your shell to fetch the dependencies.
Add a second using macro use Arc.Ecto.Definition
to the top of your Arc definitions.
defmodule MyApp.Avatar do
use Arc.Definition
use Arc.Ecto.Definition
# ...
end
This provides a set of functions to ease integration with Arc and Ecto. In particular:
- Definition of a custom Ecto Type responsible for storing the images.
- Url generation with a cache-busting timestamp query parameter
Arc attachments should be stored in a string column, with a name indicative of the attachment.
create table :users do
add :avatar, :string
end
Add a using statement use Arc.Ecto.Schema
to the top of your ecto schema, and specify the type of the column in your schema as MyApp.Avatar.Type
.
Attachments can subsequently be passed to Arc's storage though a Changeset cast_attachments/3
function, following the syntax of cast/3
defmodule MyApp.User do
use MyApp.Web, :model
use Arc.Ecto.Schema
schema "users" do
field :name, :string
field :avatar, MyApp.Avatar.Type
end
@doc """
Creates a changeset based on the `data` and `params`.
If no params are provided, an invalid changeset is returned
with no validation performed.
"""
def changeset(user, params \\ :invalid) do
user
|> cast(params, [:name])
|> cast_attachments(params, [:avatar])
|> validate_required([:name, :avatar])
end
end
@doc """
Given params of:
%{
"id" => 1,
"user" => %{
"avatar" => %Plug.Upload{
content_type: "image/png",
filename: "selfie.png",
path: "/var/folders/q0/dg42x390000gp/T//plug-1434/multipart-765369-5"}
}
}
"""
def update(conn, %{"id" => id, "user" => user_params}) do
user = Repo.get(User, id)
changeset = User.changeset(user, user_params)
if changeset.valid? do
Repo.update(changeset)
conn
|> put_flash(:info, "User updated successfully.")
|> redirect(to: user_path(conn, :index))
else
render conn, "edit.html", user: user, changeset: changeset
end
end
Both public and signed urls will include the timestamp for cache busting, and are retrieved the exact same way as using Arc directly.
user = Repo.get(User, 1)
# To receive a single rendition:
MyApp.Avatar.url({user.avatar, user}, :thumb)
#=> "https://bucket.s3.amazonaws.com/uploads/avatars/1/thumb.png?v=63601457477"
# To receive all renditions:
MyApp.Avatar.urls({user.avatar, user})
#=> %{original: "https://.../original.png?v=1234", thumb: "https://.../thumb.png?v=1234"}
# To receive a signed url:
MyApp.Avatar.url({user.avatar, user}, signed: true)
MyApp.Avatar.url({user.avatar, user}, :thumb, signed: true)
Copyright 2015 Sean Stavropoulos
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.