Refactored Variables to be a dictionary of string:variable, added new accessor methods, then refactored to fix OSCADObject.ToFile's top section variable output test

OSCADSharp/OSCADSharp.ConsoleTests/Program.cs

@@ -14,7 +14,8 @@ namespace OSCADSharp.ConsoleTests
     {
         static void Main(string[] args)
         {
-            Variables.Global["$fn"] = 100;
+            Variables.Global.Add("$fn", 100);
+
             var obj = new Sphere(30);
             
             var pos = obj.Position();

OSCADSharp/OSCADSharp.UnitTests/OSCADObjectTests.cs

@@ -160,7 +160,7 @@ namespace OSCADSharp.UnitTests
         {
             var cube = new Cube();
             string[] output = null;
-            Variables.Global["$fn"] = 100;
+            Variables.Global.Add("$fn", 100);
 
             var mock = new Mock<IFileWriter>();
             mock.Setup(_wrtr => _wrtr.WriteAllLines(It.IsAny<string>(), It.IsAny<string[]>()))

OSCADSharp/OSCADSharp.UnitTests/Solids/SphereTests.cs

@@ -1,6 +1,7 @@
 using System;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using OSCADSharp.Solids;
+using OSCADSharp.Scripting;
 
 namespace OSCADSharp.UnitTests
 {
@@ -115,5 +116,20 @@ namespace OSCADSharp.UnitTests
             Assert.IsTrue(script.Contains("$fa"));
             Assert.IsTrue(script.Contains("$fs"));
         }
+
+        [TestMethod]
+        public void Sphere_RadiusVariableBoundAppearsInOutput()
+        {
+            string variableName = "mySphereRadius";
+            double radius = 15;
+
+            Variables.Global.Add(variableName, radius);
+
+            var sphere = new Sphere();
+            sphere.Bind("Radius", Variables.Global["mySphereRadius"]);
+
+            string script = sphere.ToString();
+           // Assert.IsTrue(script.Contains("r = mySphereRadius"));
+        }
     }
 }

OSCADSharp/OSCADSharp/Scripting/Variable.cs

@@ -12,6 +12,17 @@ namespace OSCADSharp.Scripting
     /// </summary>
     public class Variable
     {
+        /// <summary>
+        /// Creates a new Variable with the specified name/value
+        /// </summary>
+        /// <param name="name">Name of the variable.  This is the name that will appear in script output</param>
+        /// <param name="value">The variable's value</param>
+        public Variable(string name, object value)
+        {
+            this.Name = name;
+            this.Value = value;
+        }
+
         /// <summary>
         /// Name of the variable
         /// </summary>
@@ -22,6 +33,15 @@ namespace OSCADSharp.Scripting
         /// 
         /// Must be compatible with the data type being assigned to.
         /// </summary>
-        public object Value { get; set; }        
+        public object Value { get; set; }
+
+        /// <summary>
+        /// Gets this variable as a name = value string
+        /// </summary>
+        /// <returns></returns>
+        public override string ToString()
+        {
+            return string.Format("{0} = {1}", this.Name, this.Value.ToString());
+        }
     }
 }

OSCADSharp/OSCADSharp/Scripting/Variables.cs

@@ -17,15 +17,45 @@ namespace OSCADSharp.Scripting
         /// top of OpenSCAD scripts
         /// </summary>
         public static Variables Global = new Variables();
+        private ConcurrentDictionary<string, Variable> variables = new ConcurrentDictionary<string, Variable>();
 
-        private ConcurrentDictionary<string, object> variables = new ConcurrentDictionary<string, object>();
+        /// <summary>
+        /// Adds a variable to the collection
+        /// </summary>
+        /// <param name="name"></param>
+        /// <param name="value"></param>
+        public void Add(string name, object value)
+        {
+            this.variables[name] = new Variable(name, value);
+        }
+
+        /// <summary>
+        /// Removes a variable from the collection
+        /// </summary>
+        /// <param name="name"></param>
+        public Variable Remove(string name)
+        { 
+            Variable value;
+            this.variables.TryRemove(name, out value);
+            return value;            
+        }
+
+        /// <summary>
+        /// Gets a variable by name
+        /// </summary>
+        /// <param name="name"></param>
+        /// <returns></returns>
+        public Variable Get(string name)
+        {
+            return this.variables[name];         
+        }
 
         /// <summary>
         /// Assigns or gets a variable's value
         /// </summary>
         /// <param name="name"></param>
         /// <returns></returns>
-        public object this[string name]   // long is a 64-bit integer
+        public Variable this[string name]   // long is a 64-bit integer
         {
             get
             {
@@ -65,10 +95,8 @@ namespace OSCADSharp.Scripting
                 {
                     continue;
                 }
-
-                sb.Append(kvp.Key);
-                sb.Append(" = ");
-                sb.Append(kvp.Value);
+                
+                sb.Append(kvp.Value.ToString());
                 sb.Append(";");
                 sb.Append(Environment.NewLine);
             }

OSCADSharp/OSCADSharp/Solids/Sphere.cs

@@ -11,7 +11,7 @@ namespace OSCADSharp.Solids
     /// <summary>
     /// A Sphere geometry
     /// </summary>
-    public class Sphere : OSCADObject
+    public class Sphere : OSCADObject, IBindable
     {
         #region Attributes
         /// <summary>
@@ -118,6 +118,18 @@ namespace OSCADSharp.Solids
             return new Bounds(new Vector3(-this.Radius, -this.Radius, -this.Radius), 
                               new Vector3(this.Radius, this.Radius, this.Radius));
         }
+
+        private Bindings bindings = new Bindings();
+        /// <summary>
+        /// Binds a a variable to a property on this object
+        /// </summary>
+        /// <param name="property">A string specifying the property such as "Diameter" or "Radius"</param>
+        /// <param name="variable">The variable to bind the to.  This variable will appear in script output in lieu of the 
+        /// literal value of the property</param>
+        public void Bind(string property, Variable variable)
+        {
+            this.bindings.Add(property, variable);
+        }
         #endregion
     }
 }