Adzz
Casting Sugar - Announcing EctoMorph, a lib to help casting between structs for Ecto
Ecto is great, we use it for validations. But validating different embeds can quickly get confusing, and there are some ways I found it a bit cumbersome.
I’ve created a lib to help add some sugar to what Ecto does, we’ve been using it in prod and it has been going well so far. Some examples, say you have a schema like this:
defmodule Embed do
use Ecto.Schema
embedded_schema do
field(:bar, :string)
end
end
defmodule Test do
use Ecto.Schema
embedded_schema do
field(:thing, :string)
embeds_one(:embed, Embed)
end
end
Usually you would have to do this:
Ecto.Changeset.cast(%Test{}, %{"thing" => "foo", "embed" => %{"bar"=> "baz"}}, [:thing])
|> Ecto.Changeset.cast_embed(:embed)
With EctoMorph you can do this:
EctoMorph.to_struct(%{"thing" => "foo", "embed" => %{"bar"=> "baz"}}, Test)
I would love feedback on whether people think this is useful, or feature requests!
Repo: https://github.com/Adzz/ecto_morph
I went into more detail here: https://medium.com/@ItizAdz/ecto-cast-ing-sugar-31bddbc62cd7
Most Liked
Adzz
Just by way of a feature update here are some of the things that are now available with ecto_morph:
- Bug fix: We now ignore through associations when casting or generating changesets. Those kinds of associations are readonly anyway, so we just ensure we don’t error.
- to_struct has been renamed to
cast_to_struct. - You can specify a list of fields to filter the changes by, like in ecto, but this is recursive like so:
%{comments: [%{like: %{count: 10, ignored: "okay"}}}]}
|> EctoMorph.cast_to_struct(Post, [comments: [like: :count]])
You can now validate nested relations
json = %{
"has_many" => [
%{"steamed_hams" => [%{"pickles" => 1}, %{"pickles" => 2}]},
%{"steamed_hams" => [%{"pickles" => 1}]},
%{"steamed_hams" => [%{"pickles" => 4}, %{"pickles" => 5}]}
]
}
# Here each of the steamed_hams above will have their pickle count validated:
EctoMorph.generate_changeset(json, MySchema)
|> EctoMorph.validate_nested_changeset([:has_many, :steamed_hams], fn changeset ->
changeset
|> Ecto.Changeset.validate_number(:pickles, greater_than: 3)
end)
Popular in Libraries
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Enabling companies to succeed by building software people love.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Producing high quality Elixir screencasts since 2017.
Enabling companies to succeed by building software people love.
The deployment platform built for Elixir: PaaS ease, VPS control.
Courses that'll move you from confusion to "Aha, now I get it!"