MLEM/Docs/articles/raw_content.md

# Raw Content Manager

Sometimes, there's a good reason for wanting to load game assets directly rather than using the MonoGame Content Pipeline, which packs files into a binary `xnb` format. Those reasons include, for example, making your game easily moddable or allowing for texture packs.

The **MLEM.Data** package contains a solution for this: `RawContentManager`.

## What it does
A raw content manager works very similarly to a regular `ContentManager`: You can load different types of assets through the `Load<T>` method, and they will automatically be managed and disposed when the game closes.

However, the `RawContentManager` loads assets in their usual file type, rather than `xnb`, meaning that they don't have to be compiled using the Content Pipeline first. 

## How to use it
To create a new raw content manager, simply call its constructor in your `LoadContent` method. Optionally, you can add it as a game component, which will automatically dispose it when the game closes.
```cs
protected override void LoadContent() {
    this.rawContent = new RawContentManager(this.Services);
    this.Components.Add(this.rawContent);

    // load other content here
}
```

Then, you can simply load an asset in your `Content` directory like you would with the regular `ContentManager`:
```cs
this.testTexture = this.rawContent.Load<Texture2D>("Textures/Test");
```

## Adding more content types
By default, the raw content manager supports the following types, as long as their files are appended with one of the supported file extensions:
- `Texture2D` (png, bmp, gif, jpg, tif, dds)
- `SoundEffect` (ogg, wav, mp3)
- `Song` (gg, wav, mp3)
- Any XML files (xml)
- Any JSON files (json, json5, jsonc)

To add more content types that can be loaded by the raw content manager, you simply have to extend either `RawContentReader` or the generic version, `RawContentReader<T>`. For example, this is a content reader that loads a `txt` file as a string:
```cs
using System.IO;
using MLEM.Data.Content;

namespace Test {
    public class StringReader : RawContentReader<string> {

        public override string[] GetFileExtensions() {
            // return an array of supported file extensions
            return new[] {"txt"};
        }

        protected override string Read(RawContentManager manager, string assetPath, Stream stream, string existing) {
            // use the stream (or the asset path) here and
            // return the loaded content file
            using (var reader = new StreamReader(stream))
                return reader.ReadToEnd();
        }

    }
}
```
As `RawContentManager` automatically collects all raw content readers in the loaded assemblies, you don't have to register your custom reader anywhere.

## Environments without reflection or with trimming
By default, the `RawContentManager` finds all types that extend `RawContentReader` in all loaded assemblies, so they don't have to be added manually. This won't work in environments like NativeAOT, where reflection isn't as readily available, or in assemblies that get trimmed.

If you're in an environment with this restriction, you can manually collect all the content readers that you plan on using and call the constructor that accepts a list of content readers instead:
```csharp
protected override void LoadContent() {
    var neededReaders = new List<RawContentReader> {
        new Texture2DReader(), new JsonReader() // ...
    };
    this.rawContent = new RawContentManager(this.Services, neededReaders);
    this.Components.Add(this.rawContent);
}
```