Content Collections

Collections group Markdown entries such as posts, docs, changelog items, or authors.

Define a collection

site do
  collections do
    collection :posts, "content/posts" do
      permalink "/blog/:slug/"
      layout "post.html"

      schema %{
        required(:title) => String.t(),
        required(:date) => String.t(),
        optional(:draft) => boolean(),
        optional(:tags) => [String.t()]
      }
    end
  end
end

Each Markdown file in content/posts/ becomes a validated entry and a static page at the collection permalink.

Entry data

entry.metadata contains original string-keyed frontmatter. entry.data contains schema-normalized values:

<%= for post <- @collections.posts do %>
  <a href={post.route_path}><%= post.data.title %></a>
<% end %>

Collection entry layouts receive @entry for the current entry.

Zoi schemas

Use Zoi when runtime coercion or refinements are useful:

collection :posts, "content/posts" do
  schema Zoi.map(%{
    title: Zoi.string(),
    tags: Zoi.array(Zoi.string()) |> Zoi.optional()
  }, coerce: true)
end

Collection helpers

Astral includes helpers for common entry filtering and sorting:

posts =
  @site
  |> Astral.Collection.entries(:posts)
  |> Astral.Collection.published()
  |> Astral.Collection.sort_by_date(:desc)

Tags and categories are userland. If your site needs tag pages, build them from collection data and generated routes.