feat: datasheet upload and auto-retrieve

- store datasheet PDFs on the server
- download PDF automatically when given a link

lib/components_elixir/inventory/component.ex

@@ -18,6 +18,7 @@ defmodule ComponentsElixir.Inventory.Component do
     field :legacy_position, :string
     field :count, :integer, default: 0
     field :datasheet_url, :string
+    field :datasheet_filename, :string
     field :image_filename, :string
 
     belongs_to :category, Category
@@ -29,7 +30,7 @@ defmodule ComponentsElixir.Inventory.Component do
   @doc false
   def changeset(component, attrs) do
     component
-    |> cast(attrs, [:name, :description, :keywords, :position, :count, :datasheet_url, :image_filename, :category_id, :storage_location_id])
+    |> cast(attrs, [:name, :description, :keywords, :position, :count, :datasheet_url, :datasheet_filename, :image_filename, :category_id, :storage_location_id])
     |> validate_required([:name, :category_id])
     |> validate_length(:name, min: 1, max: 255)
     |> validate_length(:description, max: 2000)
@@ -59,6 +60,14 @@ defmodule ComponentsElixir.Inventory.Component do
     |> cast(attrs, [:image_filename])
   end
 
+  @doc """
+  Changeset for updating component datasheet.
+  """
+  def datasheet_changeset(component, attrs) do
+    component
+    |> cast(attrs, [:datasheet_filename])
+  end
+
   defp validate_url(changeset, field) do
     validate_change(changeset, field, fn ^field, url ->
       if url && url != "" do
@@ -78,6 +87,12 @@ defmodule ComponentsElixir.Inventory.Component do
   def has_image?(%__MODULE__{image_filename: filename}) when is_binary(filename), do: true
   def has_image?(_), do: false
 
+  @doc """
+  Returns true if the component has a datasheet file.
+  """
+  def has_datasheet?(%__MODULE__{datasheet_filename: filename}) when is_binary(filename), do: true
+  def has_datasheet?(_), do: false
+
   @doc """
   Returns the search text for this component.
   """