# `Scrypath.Loader`
[🔗](https://github.com/szTheory/scrypath/blob/v0.3.17/lib/scrypath/loader.ex#L1)

Loads the current source records for search document ids.

Oban sync jobs carry document ids, not document data. When a job runs, it
loads the records as they are now, so a retried or delayed job never sends
an older copy over newer index data.

By default the loader queries the schema by its `document_id` field with the
configured `:repo`, then applies the schema's declared `preload:`:

    use Scrypath,
      fields: [:name, :category_name],
      preload: [:category]

A schema that needs full control, for example tenant-scoped repos, soft
deletes, or document ids that are not a column, defines `search_records/2`.
It receives the document ids and a context map with `:repo`, and returns the
records that still exist and should be searchable:

    def search_records(ids, %{repo: repo}) do
      from(p in __MODULE__, where: p.id in ^ids, preload: :category)
      |> repo.all(skip_tenant_id: true)
    end

Ids with no returned record are removed from the index.

# `check_loadable`

```elixir
@spec check_loadable(
  module(),
  keyword()
) :: :ok | {:error, atom()}
```

Checks that records for `schema_module` can be loaded by document id.

Returns `{:error, :search_records_required}` for schemas with custom document
ids and no `search_records/2`, and `{:error, :repo_required}` when no `:repo`
is configured.

# `custom_loader?`

```elixir
@spec custom_loader?(module()) :: boolean()
```

Whether the schema defines its own `search_records/2` loader.

# `ensure_loadable!`

```elixir
@spec ensure_loadable!(
  module(),
  keyword()
) :: :ok
```

Raises when records for `schema_module` cannot be loaded by document id.

Called before an Oban job is queued so a missing repo or an unmappable custom
document id fails at the call site instead of inside the worker.

# `load`

```elixir
@spec load(module(), [term()], keyword()) ::
  {:ok, [struct()], [term()]} | {:error, term()}
```

Returns `{:ok, records, missing_ids}` for the given document ids.

`missing_ids` keeps the caller's id values for documents whose records no
longer exist.

---

*Consult [api-reference.md](api-reference.md) for complete listing*