Roblox-File-Format/README.md

# Roblox-File-Format
A C# library designed to make it easy to create and manipulate files in Roblox's model/place file format!

# Usage
The `RobloxFile` class is the main entry point for opening and saving files.
You can provide one of three possible inputs to `RobloxFile.Open`:

- A `string` containing the path to some `*.rbxl/.rbxlx` or `*.rbxm/*.rbxmx` to read from.
- A `Stream` or `byte[]` to be read from directly.

```cs
RobloxFile file = RobloxFile.Open(@"A:\Path\To\Some\File.rbxm");

// Make some changes...

file.Save(@"A:\Path\To\Some\NewFile.rbxm");
```

Depending on the format being used by the file, it will return either a `BinaryRobloxFile` or an `XmlRobloxFile`, both of which derive from the `RobloxFile` class.
At this time converting between Binary and XML is not directly supported, but in theory it shouldn't cause too many problems.

```cs
if (file is BinaryRobloxFile)
    Console.WriteLine("This file used Roblox's binary format!");
else
    Console.WriteLine("This file used Roblox's xml format!");
```

This library contains a full implementation of Roblox's DOM, meaning that you can directly iterate over the Instance tree of the file as if you were writing code in Lua for Roblox!
The `RobloxFile` class inherits from the provided `Instance` class in this library, serving as the root entry point to the contents of the file:

```cs
foreach (Instance descendant in file.GetDescendants()) do
    Console.WriteLine(descendant.GetFullName());
```

You can use type casting to read the properties specific to a derived class of Instance.
Full type coverage is provided for all of Roblox's built-in types under the `RobloxFiles.DataTypes` namespace.
Additionally, all of Roblox's enums are defined under the `RobloxFiles.Enums` namespace.

```cs
Workspace workspace = file.FindFirstChildWhichIsA<Workspace>();

if (workspace != null)
{
    BasePart primary = workspace.PrimaryPart;
    
    if (primary != null)
    {
        primary.CFrame = new CFrame(1, 2, 3);
        primary.Size = new Vector3(4, 5, 6);
    }
    
    workspace.StreamingPauseMode = StreamingPauseMode.ClientPhysicsPause;
    Console.WriteLine($"Workspace.FilteringEnabled: {workspace.FilteringEnabled}");  
}  
```

Property values are populated upon opening a file through `Property` binding objects. 
The read-only dictionary `Instance.Properties` provides a lookup for these bindings, thus allowing for generic iteration over the properties of an Instance!
For example, this function will count all distinct `Content` urls in the `Workspace` a given file:
```cs
static void CountAssets(string path)
{
    Console.WriteLine("Opening file...");
    RobloxFile target = RobloxFile.Open(path);

    var workspace = target.FindFirstChildOfClass<Workspace>();
    var assets = new HashSet<string>();

    if (workspace == null)
    {
        Console.WriteLine("No workspace found!");
        Debugger.Break();

        return;
    }

    foreach (Instance inst in workspace.GetDescendants())
    {
        var instPath = inst.GetFullName();
        var props = inst.Properties;

        foreach (var prop in props)
        {
            Property binding = prop.Value;
            Content content = binding.CastValue<Content>();

            if (content != null)
            {
                string propName = prop.Key;
                string url = content.Url.Trim();

                var id = Regex
                    .Match(url, pattern)?
                    .Value;

                if (id != null && id.Length > 5)
                    url = "rbxassetid://" + id;

                if (url.Length > 0 && !assets.Contains(url))
                {
                    Console.WriteLine($"[{url}] at {instPath}.{propName}");
                    assets.Add(url);
                }
            }
        }
    }

    Console.WriteLine("Done! Press any key to continue...");
    Console.Read();
}
```

At this time, property bindings are only generated upon opening or saving a file. Creating your own instance will not automatically generate these bindings, though this behavior will likely be changed in the near future.