docs: Change docs to align them with the current state of resource fetcher

Author: msluszniak

.cspell-wordlist.txt

@@ -105,3 +105,6 @@ POTTEDPLANT
 TVMONITOR
 sublist
 TTFT
+pogodin
+kesha
+antonov

docs/docs/01-fundamentals/01-getting-started.md

@@ -62,7 +62,7 @@ Installation is pretty straightforward, just use your favorite package manager.
   </TabItem>
 </Tabs>
 
-If you're using bare React Native (instead of a managed Expo project), you also need to install Expo Modules because the underlying implementation relies on expo-file-system. Since expo-file-system is an Expo package, bare React Native projects need **Expo Modules** to properly integrate and use it. The link provided (https://docs.expo.dev/bare/installing-expo-modules/) offers guidance on setting up Expo Modules in a bare React Native environment.
+Our library offers support for both bare React Native and Expo projects. We encourage you to use Expo project if possible. If you are planning to migrate from bare React Native to Expo project, the link (https://docs.expo.dev/bare/installing-expo-modules/) offers a guidance on setting up Expo Modules in a bare React Native environment.
 
 If you plan on using your models via require() instead of fetching them from a url, you also need to add following lines to your `metro.config.js`:
 

docs/docs/01-fundamentals/02-loading-models.md

@@ -4,6 +4,46 @@ title: Loading Models
 
 There are three different methods available for loading model files, depending on their size and location.
 
+## Prerequisites
+
+In our library, you can use two different resource fetching mechanisms. One is implemented using Expo module, the other one uses external file-system library. We encourage you to use implementation utilizing Expo if possible. But sometimes you cannot add Expo module to your project, then you should use bare React Native implementation.
+
+To use initialize Expo adapter, please add these libraries:
+
+```bash
+yarn add @rn-executorch/expo-adapter
+yarn add expo-file-system expo-asset
+```
+
+and then add the following code in your React Native app:
+
+```typescript
+import { initExecutorch } from 'react-native-executorch';
+import { ExpoResourceFetcher } from '@react-native-executorch/expo-resource-fetcher';
+
+initExecutorch({
+  resourceFetcher: ExpoResourceFetcher,
+});
+```
+
+If you cannot use Expo in your project, proceed with the following steps:
+
+```bash
+yarn add @rn-executorch/bare-adapter
+yarn add @dr.pogodin/react-native-fs @kesha-antonov/react-native-background-downloader
+```
+
+and
+
+```typescript
+import { initExecutorch } from 'react-native-executorch';
+import { BareResourceFetcher } from '@rn-executorch/bare-adapter';
+
+initExecutorch({
+  resourceFetcher: BareResourceFetcher,
+});
+```
+
 **1. Load from React Native assets folder (For Files < 512MB)**
 
 ```typescript

docs/docs/01-fundamentals/03-frequently-asked-questions.md

@@ -31,7 +31,7 @@ If your model doesn't support it, you can still work around it using context. Fo
 
 ### Can I use React Native ExecuTorch in bare React Native apps?
 
-To use the library, you need to install Expo Modules first. For a setup guide, refer to [this tutorial](https://docs.expo.dev/bare/installing-expo-modules/). This is because we use Expo File System under the hood to download and manage the model binaries.
+Yes, staring from version `0.8.x` you can use React Native ExecuTorch in bare React Native apps. You just need to use bare React Native resource fetcher instead of Expo one, see: [Loading models section](./02-loading-models.md) for more details.
 
 ### Do you support the old architecture?
 

packages/bare-resource-fetcher/src/ResourceFetcherUtils.ts

@@ -88,7 +88,7 @@ export namespace ResourceFetcherUtils {
         await RNFS.mkdir(RNEDirectory);
       } catch (error) {
         throw new RnExecutorchError(
-          RnExecutorchErrorCode.AccessFailed,
+          RnExecutorchErrorCode.FileWriteFailed,
           `Failed to create directory at ${RNEDirectory}`,
           error
         );

packages/expo-resource-fetcher/src/ResourceFetcherUtils.ts

@@ -101,7 +101,7 @@ export namespace ResourceFetcherUtils {
         await makeDirectoryAsync(RNEDirectory, { intermediates: true });
       } catch (error) {
         throw new RnExecutorchError(
-          RnExecutorchErrorCode.AccessFailed,
+          RnExecutorchErrorCode.FileWriteFailed,
           `Failed to create directory at ${RNEDirectory}`,
           error
         );