# Prepare For Downloading

[`BaseRegion`s](/v9/bulk-downloading/regions.md) must be converted to `DownloadableRegion`s before they can be used to download tiles.

These contain the original `BaseRegion`, but also some other information necessary for downloading, such as zoom levels and URL templates.

```dart
final downloadableRegion = region.toDownloadable(
    minZoom: 1,
    maxZoom: 18,
    options: TileLayer(
        urlTemplate: '<your tile server>',
        userAgentPackageName: 'com.example.app',
    ),
),
```

{% embed url="<https://pub.dev/documentation/flutter_map_tile_caching/latest/flutter_map_tile_caching/BaseRegion/toDownloadable.html>" %}

{% hint style="info" %}
The `TileLayer` passed to the `options` parameter must include both a `urlTemplate` (or WMS configuration) and a `userAgentPackageName`, unless it is only being used to [`check` the number of tiles in the region](#checking-number-of-tiles).
{% endhint %}

## Checking Number Of Tiles

Before continuing to downloading the region, you can use `check()` to count the number of tiles it will attempt to download. This is accessible through `FMTCStore().download`.

The method takes the `DownloadableRegion` generated above, and will return an `int` number of tiles. For larger regions, this may take a few seconds.

{% hint style="warning" %}
This figure will not take into account any skipped sea tiles or skipped existing tiles, as those are handled at the time of download.
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://fmtc.jaffaketchup.dev/v9/bulk-downloading/prepare.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.