Add more MapLoaderSystem TextReader/TextWriter overloads

Co-authored-by: kaylie <moony@hellomouse.net>

RELEASE-NOTES.md

@@ -41,6 +41,7 @@ END TEMPLATE-->
 
 * If a sandbox error is caused by a compiler-generated method, the engine will now attempt to point out which using code is responsible.
 * Added `OrderedDictionary<TKey, TValue>` and `System.StringComparer` to the sandbox whitelist.
+* Added more overloads to `MapLoaderSystem` taking `TextReader`/`TextWriter` where appropriate.
 
 ### Bugfixes
 

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.Load.cs

@@ -19,8 +19,8 @@ namespace Robust.Shared.EntitySerialization.Systems;
 public sealed partial class MapLoaderSystem
 {
     /// <summary>
-    /// Tries to load entities from a yaml file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     Tries to load entities from a YAML file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
-    /// <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
     /// </summary>
     public bool TryLoadGeneric(
         ResPath file,
@@ -30,6 +30,7 @@ public sealed partial class MapLoaderSystem
     {
         grids = null;
         maps = null;
+
         if (!TryLoadGeneric(file, out var data, options))
             return false;
 
@@ -39,33 +40,29 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load entities from a YAML file, taking in a raw byte stream.
+    ///     Tries to load entities from a YAML text stream. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
     /// </summary>
-    /// <param name="file">The file contents to load from.</param>
-    /// <param name="fileName">
-    /// The name of the file being loaded. This is used purely for logging/informational purposes.
-    /// </param>
-    /// <param name="result">The result of the load operation.</param>
-    /// <param name="options">Options for the load operation.</param>
-    /// <returns>True if the load succeeded, false otherwise.</returns>
-    /// <seealso cref="M:Robust.Shared.EntitySerialization.Systems.MapLoaderSystem.TryLoadGeneric(Robust.Shared.Utility.ResPath,Robust.Shared.EntitySerialization.LoadResult@,System.Nullable{Robust.Shared.EntitySerialization.MapLoadOptions})"/>
     public bool TryLoadGeneric(
-        Stream file,
+        TextReader reader,
-        string fileName,
+        string source,
-        [NotNullWhen(true)] out LoadResult? result,
+        [NotNullWhen(true)] out HashSet<Entity<MapComponent>>? maps,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         MapLoadOptions? options = null)
     {
-        result = null;
+        grids = null;
-
+        maps = null;
-        if (!TryReadFile(new StreamReader(file), out var data))
+        if (!TryLoadGeneric(reader, source, out var data, options))
             return false;
 
-        return TryLoadGeneric(data, fileName, out result, options);
+        maps = data.Maps;
+        grids = data.Grids;
+        return true;
     }
 
     /// <summary>
-    /// Tries to load entities from a yaml file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     Tries to load entities from a YAML file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
-    /// <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
     /// </summary>
     /// <param name="file">The file to load.</param>
     /// <param name="result">Data class containing information about the loaded entities</param>
@@ -80,9 +77,45 @@ public sealed partial class MapLoaderSystem
         return TryLoadGeneric(data, file.ToString(), out result, options);
     }
 
-    private bool TryLoadGeneric(
+    /// <summary>
+    ///     Tries to load entities from a YAML text stream. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    /// </summary>
+    /// <param name="reader">The text to load.</param>
+    /// <param name="source">The name of the source, if any. This should be your file path (for example)</param>
+    /// <param name="result">Data class containing information about the loaded entities</param>
+    /// <param name="options">Optional Options for configuring loading behaviour.</param>
+    public bool TryLoadGeneric(TextReader reader, string source, [NotNullWhen(true)] out LoadResult? result, MapLoadOptions? options = null)
+    {
+        result = null;
+
+        if (!TryReadFile(reader, out var data))
+            return false;
+
+        return TryLoadGeneric(data, source, out result, options);
+    }
+
+    /// <summary>
+    ///     Tries to load entities from a YAML text stream. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    /// </summary>
+    /// <param name="stream">The stream containing the text to load.</param>
+    /// <param name="source">The name of the source, if any. This should be your file path (for example)</param>
+    /// <param name="result">Data class containing information about the loaded entities</param>
+    /// <param name="options">Optional Options for configuring loading behaviour.</param>
+    public bool TryLoadGeneric(Stream stream, string source, [NotNullWhen(true)] out LoadResult? result, MapLoadOptions? options = null)
+    {
+        result = null;
+
+        if (!TryReadFile(new StreamReader(stream, leaveOpen: true), out var data))
+            return false;
+
+        return TryLoadGeneric(data, source, out result, options);
+    }
+
+    public bool TryLoadGeneric(
         MappingDataNode data,
-        string fileName,
+        string source,
         [NotNullWhen(true)] out LoadResult? result,
         MapLoadOptions? options = null)
     {
@@ -118,7 +151,7 @@ public sealed partial class MapLoaderSystem
 
         if (!deserializer.TryProcessData())
         {
-            Log.Debug($"Failed to process entity data in {fileName}");
+            Log.Debug($"Failed to process entity data in {source}");
             return false;
         }
 
@@ -128,7 +161,7 @@ public sealed partial class MapLoaderSystem
             && deserializer.Result.Category != FileCategory.Unknown)
         {
             // Did someone try to load a map file as a grid or vice versa?
-            Log.Error($"Map {fileName} does not contain the expected data. Expected {expected} but got {deserializer.Result.Category}");
+            Log.Error($"Map {source} does not contain the expected data. Expected {expected} but got {deserializer.Result.Category}");
             Delete(deserializer.Result);
             return false;
         }
@@ -139,7 +172,7 @@ public sealed partial class MapLoaderSystem
         }
         catch (Exception e)
         {
-            Log.Error($"Caught exception while creating entities for map {fileName}: {e}");
+            Log.Error($"Caught exception while creating entities for map {source}: {e}");
             Delete(deserializer.Result);
             throw;
         }
@@ -149,7 +182,7 @@ public sealed partial class MapLoaderSystem
         if (opts.ExpectedCategory is { } exp && exp != deserializer.Result.Category)
         {
             // Did someone try to load a map file as a grid or vice versa?
-            Log.Error($"Map {fileName} does not contain the expected data. Expected {exp} but got {deserializer.Result.Category}");
+            Log.Error($"Map {source} does not contain the expected data. Expected {exp} but got {deserializer.Result.Category}");
             Delete(deserializer.Result);
             return false;
         }
@@ -184,12 +217,33 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load a regular (non-map, non-grid) entity from a file.
+    ///     Tries to load a regular (non-map, non-grid) entity from a YAML file.
-    /// The loaded entity will initially be in null-space.
+    ///     The loaded entity will initially be in null-space.
-    /// If the file does not contain exactly one orphaned entity, this will return false and delete loaded entities.
+    ///     If the file does not contain exactly one orphaned entity, this will return false and delete loaded entities.
     /// </summary>
     public bool TryLoadEntity(
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<TransformComponent>? entity,
+        DeserializationOptions? options = null)
+    {
+        entity = null;
+        if (!TryGetReader(file, out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadEntity(reader, file.ToString(), out entity, options);
+        }
+    }
+
+    /// <summary>
+    ///     Tries to load a regular (non-map, non-grid) entity from a YAML text stream.
+    ///     The loaded entity will initially be in null-space.
+    ///     If the file does not contain exactly one orphaned entity, this will return false and delete loaded entities.
+    /// </summary>
+    public bool TryLoadEntity(
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<TransformComponent>? entity,
         DeserializationOptions? options = null)
     {
@@ -200,7 +254,7 @@ public sealed partial class MapLoaderSystem
         };
 
         entity = null;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (result.Orphans.Count == 1)
@@ -215,12 +269,35 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load a grid entity from a file and parent it to the given map.
+    ///     Tries to load a grid entity from a YAML file and parent it to the given map.
-    /// If the file does not contain exactly one grid, this will return false and delete loaded entities.
+    ///     If the file does not contain exactly one grid, this will return false and delete loaded entities.
     /// </summary>
     public bool TryLoadGrid(
         MapId map,
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        grid = null;
+        if (!TryGetReader(file, out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadGrid(map, reader, file.ToString(), out grid, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Tries to load a grid entity from a YAML text stream and parent it to the given map.
+    ///     If the file does not contain exactly one grid, this will return false and delete loaded entities.
+    /// </summary>
+    public bool TryLoadGrid(
+        MapId map,
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
         DeserializationOptions? options = null,
         Vector2 offset = default,
@@ -236,7 +313,7 @@ public sealed partial class MapLoaderSystem
         };
 
         grid = null;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (result.Grids.Count == 1)
@@ -250,11 +327,35 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load a grid entity from a file and parent it to a newly created map.
+    /// Tries to load a grid entity from a YAML file and parent it to a newly created map.
     /// If the file does not contain exactly one grid, this will return false and delete loaded entities.
     /// </summary>
     public bool TryLoadGrid(
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapComponent>? map,
+        [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        grid = null;
+        map = null;
+        if (!TryGetReader(file, out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadGrid(reader, file.ToString(), out map, out grid, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    /// Tries to load a grid entity from a YAML text stream and parent it to a newly created map.
+    /// If the file does not contain exactly one grid, this will return false and delete loaded entities.
+    /// </summary>
+    public bool TryLoadGrid(
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapComponent>? map,
         [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
         DeserializationOptions? options = null,
@@ -267,7 +368,7 @@ public sealed partial class MapLoaderSystem
         if (opts.PauseMaps)
             _mapSystem.SetPaused(mapUid, true);
 
-        if (!TryLoadGrid(mapId, path, out grid, options, offset, rot))
+        if (!TryLoadGrid(mapId, reader, source, out grid, options, offset, rot))
         {
             Del(mapUid);
             map = null;

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.LoadMap.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Linq;
 using System.Numerics;
 using Robust.Shared.GameObjects;
@@ -15,14 +16,41 @@ namespace Robust.Shared.EntitySerialization.Systems;
 public sealed partial class MapLoaderSystem
 {
     /// <summary>
-    /// Attempts to load a file containing a single map.
+    ///     Attempts to load a YAML file containing a single map.
-    /// If the file does not contain exactly one map, this will return false and delete all loaded entities.
+    ///     If the file does not contain exactly one map, this will return false and delete all loaded entities.
     /// </summary>
     /// <remarks>
-    /// Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
     /// </remarks>
     public bool TryLoadMap(
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapComponent>? map,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        map = null;
+        grids = null;
+        if (!TryGetReader(file, out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadMap(reader, file.ToString(), out map, out grids, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Attempts to load a YAML stream containing a single map.
+    ///     If the file does not contain exactly one map, this will return false and delete all loaded entities.
+    /// </summary>
+    /// <remarks>
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    /// </remarks>
+    public bool TryLoadMap(
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapComponent>? map,
         [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         DeserializationOptions? options = null,
@@ -39,7 +67,7 @@ public sealed partial class MapLoaderSystem
 
         map = null;
         grids = null;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (result.Maps.Count == 1)
@@ -54,17 +82,47 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Attempts to load a file containing a single map, assign it the given map id.
+    ///     Attempts to load a YAML file containing a single map, assign it the given map id.
     /// </summary>
     /// <remarks>
-    /// If possible, it is better to use <see cref="TryLoadMap"/> which automatically assigns a <see cref="MapId"/>.
+    ///     If possible, it is better to use <see cref="TryLoadMap"/> which automatically assigns a <see cref="MapId"/>.
     /// </remarks>
     /// <remarks>
-    /// Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
     /// </remarks>
     public bool TryLoadMapWithId(
         MapId mapId,
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapComponent>? map,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        map = null;
+        grids = null;
+        if (!TryGetReader(file, out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadMapWithId(mapId, reader, file.ToString(), out map, out grids, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Attempts to load a YAML text stream containing a single map, assign it the given map id.
+    /// </summary>
+    /// <remarks>
+    ///     If possible, it is better to use <see cref="TryLoadMap"/> which automatically assigns a <see cref="MapId"/>.
+    /// </remarks>
+    /// <remarks>
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    /// </remarks>
+    public bool TryLoadMapWithId(
+        MapId mapId,
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapComponent>? map,
         [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         DeserializationOptions? options = null,
@@ -86,7 +144,7 @@ public sealed partial class MapLoaderSystem
             throw new Exception($"Target map already exists");
 
         opts.ForceMapId = mapId;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (!_mapSystem.TryGetMap(mapId, out var uid) || !TryComp(uid, out MapComponent? comp))
@@ -98,12 +156,35 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Attempts to load a file containing a single map, and merge its children onto another map. After which the
+    ///     Attempts to load a YAML text stream containing a single map, and merge its children onto another map. After which
-    /// loaded map gets deleted.
+    ///     the loaded map gets deleted.
     /// </summary>
     public bool TryMergeMap(
         MapId mapId,
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        grids = null;
+        if (!TryGetReader(file, out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryMergeMap(mapId, reader, file.ToString(), out grids, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Attempts to load a YAML file containing a single map, and merge its children onto another map. After which
+    ///     the loaded map gets deleted.
+    /// </summary>
+    public bool TryMergeMap(
+        MapId mapId,
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         DeserializationOptions? options = null,
         Vector2 offset = default,
@@ -123,7 +204,7 @@ public sealed partial class MapLoaderSystem
             throw new Exception($"Target map {mapId} does not exist");
 
         opts.MergeMap = mapId;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (!_mapSystem.TryGetMap(mapId, out var uid) || !TryComp(uid, out MapComponent? comp))

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.Save.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Linq;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
@@ -59,10 +60,19 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Serialize a standard (non-grid, non-map) entity and all of its children and write the result to a
+    ///     Serialize a standard (non-grid, non-map) entity and all of its children and write the result to a YAML file.
-    /// yaml file.
     /// </summary>
-    public bool TrySaveEntity(EntityUid entity, ResPath path, SerializationOptions? options = null)
+    public bool TrySaveEntity(EntityUid entity, ResPath target, SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveEntity(entity, writer, options);
+    }
+
+    /// <summary>
+    ///     Serialize a standard (non-grid, non-map) entity and all of its children and write the result to a YAML text
+    ///     stream.
+    /// </summary>
+    public bool TrySaveEntity(EntityUid entity, TextWriter target, SerializationOptions? options = null)
     {
         if (_mapQuery.HasComp(entity))
         {
@@ -97,12 +107,12 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
     /// <summary>
-    /// Serialize a map and all of its children and write the result to a yaml file.
+    /// Serialize a map and all of its children and write the result to a YAML file.
     /// </summary>
     public bool TrySaveMap(MapId mapId, ResPath path, SerializationOptions? options = null)
     {
@@ -114,9 +124,18 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Serialize a map and all of its children and write the result to a yaml file.
+    ///     Serialize a map and all of its children and write the result to a YAML file.
     /// </summary>
-    public bool TrySaveMap(EntityUid map, ResPath path, SerializationOptions? options = null)
+    public bool TrySaveMap(EntityUid map, ResPath target, SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveMap(map, writer, options);
+    }
+
+    /// <summary>
+    ///     Serialize a map and all of its children and write the result to a YAML text stream.
+    /// </summary>
+    public bool TrySaveMap(EntityUid map, TextWriter target, SerializationOptions? options = null)
     {
         if (!_mapQuery.HasComp(map))
         {
@@ -145,14 +164,23 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
     /// <summary>
-    /// Serialize a grid and all of its children and write the result to a yaml file.
+    ///     Serialize a grid and all of its children and write the result to a YAML file.
     /// </summary>
-    public bool TrySaveGrid(EntityUid grid, ResPath path, SerializationOptions? options = null)
+    public bool TrySaveGrid(EntityUid map, ResPath target, SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveGrid(map, writer, options);
+    }
+
+    /// <summary>
+    ///     Serialize a grid and all of its children and write the result to a YAML text stream.
+    /// </summary>
+    public bool TrySaveGrid(EntityUid grid, TextWriter target, SerializationOptions? options = null)
     {
         if (!_gridQuery.HasComp(grid))
         {
@@ -187,32 +215,62 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
     /// <summary>
-    /// Serialize an entities and all of their children to a yaml file.
+    ///     Serialize an entity and all of their children to a YAML file.
-    /// This makes no assumptions about the expected entity or resulting file category.
+    ///     This makes no assumptions about the expected entity or resulting file category.
-    /// If possible, use the map/grid specific variants instead.
+    ///     If possible, use the map/grid specific variants instead.
     /// </summary>
     public bool TrySaveGeneric(
         EntityUid uid,
-        ResPath path,
+        ResPath target,
         out FileCategory category,
         SerializationOptions? options = null)
     {
-        return TrySaveGeneric([uid], path, out category, options);
+        using var writer = GetWriterForPath(target);
+        return TrySaveGeneric(uid, writer, out category, options);
     }
 
     /// <summary>
-    /// Serialize one or more entities and all of their children to a yaml file.
+    ///     Serialize an entity and all of their children to a YAML text stream.
-    /// This makes no assumptions about the expected entity or resulting file category.
+    ///     This makes no assumptions about the expected entity or resulting file category.
-    /// If possible, use the map/grid specific variants instead.
+    ///     If possible, use the map/grid specific variants instead.
+    /// </summary>
+    public bool TrySaveGeneric(
+        EntityUid uid,
+        TextWriter target,
+        out FileCategory category,
+        SerializationOptions? options = null)
+    {
+        return TrySaveGeneric([uid], target, out category, options);
+    }
+
+    /// <summary>
+    ///     Serialize one or more entities and all of their children to a YAML file.
+    ///     This makes no assumptions about the expected entity or resulting file category.
+    ///     If possible, use the map/grid specific variants instead.
+    /// </summary>
+    public bool TrySaveGeneric(
+        HashSet<EntityUid> uid,
+        ResPath target,
+        out FileCategory category,
+        SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveGeneric(uid, writer, out category, options);
+    }
+
+    /// <summary>
+    ///     Serialize one or more entities and all of their children to a YAML text stream.
+    ///     This makes no assumptions about the expected entity or resulting file category.
+    ///     If possible, use the map/grid specific variants instead.
     /// </summary>
     public bool TrySaveGeneric(
         HashSet<EntityUid> entities,
-        ResPath path,
+        TextWriter target,
         out FileCategory category,
         SerializationOptions? options = null)
     {
@@ -233,10 +291,21 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
+    /// <inheritdoc cref="TrySerializeAllEntities(out MappingDataNode, SerializationOptions?)"/>
+    public bool TrySaveAllEntities(TextWriter target, SerializationOptions? options = null)
+    {
+        if (!TrySerializeAllEntities(out var data, options))
+            return false;
+
+        Write(target, data);
+        return true;
+    }
+
+
     /// <inheritdoc cref="TrySerializeAllEntities(out MappingDataNode, SerializationOptions?)"/>
     public bool TrySaveAllEntities(ResPath path, SerializationOptions? options = null)
     {

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.cs

@@ -42,17 +42,29 @@ public sealed partial class MapLoaderSystem : EntitySystem
         _gridQuery = GetEntityQuery<MapGridComponent>();
     }
 
+    private void Write(TextWriter target, MappingDataNode data)
+    {
+        var document = new YamlDocument(data.ToYaml());
+        var stream = new YamlStream {document};
+        stream.Save(new YamlMappingFix(new Emitter(target)), false);
+    }
+
+    private StreamWriter GetWriterForPath(ResPath path)
+    {
+        Log.Info($"Saving serialized results to {path}");
+        path = path.ToRootedPath();
+        _resourceManager.UserData.CreateDir(path.Directory);
+        return _resourceManager.UserData.OpenWriteText(path);
+    }
+
     private void Write(ResPath path, MappingDataNode data)
     {
         Log.Info($"Saving serialized results to {path}");
         path = path.ToRootedPath();
-        var document = new YamlDocument(data.ToYaml());
         _resourceManager.UserData.CreateDir(path.Directory);
         using var writer = _resourceManager.UserData.OpenWriteText(path);
-        {
+
-            var stream = new YamlStream {document};
+        Write(writer, data);
-            stream.Save(new YamlMappingFix(new Emitter(writer)), false);
-        }
     }
 
     public bool TryReadFile(ResPath file, [NotNullWhen(true)] out MappingDataNode? data)