Added a new WirePlacerComponent. This is used on an item, and allows a client to place electrical wires in the world by AfterAttacking a a grid square without any other wires on it.

Content.Server/GameObjects/Components/Power/WirePlacerComponent.cs

@@ -0,0 +1,60 @@
+using Content.Server.GameObjects.EntitySystems;
+using Content.Shared.Maps;
+using Robust.Server.GameObjects;
+using Robust.Server.Interfaces.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Components.Transform;
+using Robust.Shared.Interfaces.Map;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+
+namespace Content.Server.GameObjects.Components.Power
+{
+    [RegisterComponent]
+    internal class WirePlacerComponent : Component, IAfterAttack
+    {
+#pragma warning disable 169
+        [Dependency] private readonly IServerEntityManager _entityManager;
+        [Dependency] private readonly IMapManager _mapManager;
+        [Dependency] private readonly ITileDefinitionManager _tileDefinitionManager;
+#pragma warning restore 169
+
+        /// <inheritdoc />
+        public override string Name => "WirePlacer";
+
+        /// <inheritdoc />
+        public void AfterAttack(AfterAttackEventArgs eventArgs)
+        {
+            if(!_mapManager.TryGetGrid(eventArgs.ClickLocation.GridID, out var grid))
+                return;
+
+            var snapPos = grid.SnapGridCellFor(eventArgs.ClickLocation.ToWorld(_mapManager), SnapGridOffset.Center);
+            var snapCell = grid.GetSnapGridCell(snapPos, SnapGridOffset.Center);
+
+            if(grid.GetTileRef(snapPos).Tile.IsEmpty)
+                return;
+
+            var found = false;
+            foreach (var snapComp in snapCell)
+            {
+                if (!snapComp.Owner.HasComponent<PowerTransferComponent>())
+                    continue;
+
+                found = true;
+                break;
+            }
+
+            if (found)
+                return;
+            
+            var newWire = _entityManager.SpawnEntityAt("Wire", grid.GridTileToLocal(snapPos));
+            if (newWire.TryGetComponent(out SpriteComponent wireSpriteComp)
+                && Owner.TryGetComponent(out SpriteComponent itemSpriteComp))
+            {
+                wireSpriteComp.Color = itemSpriteComp.Color;
+            }
+
+            //TODO: There is no way to set this wire as above or below the floor
+        }
+    }
+}

Resources/Prototypes/Entities/items/materials.yml

@@ -66,3 +66,4 @@
     color: red
   - type: Icon
     texture: Objects/cable_coil.png
+  - type: WirePlacer