1 files changed, 159 insertions, 0 deletions

diff --git a/src/internal/WixBuildTools.XsdGen/CodeDomReader.cs b/src/internal/WixBuildTools.XsdGen/CodeDomReader.cs
new file mode 100644
index 00000000..5198f264
--- /dev/null
+++ b/src/internal/WixBuildTools.XsdGen/CodeDomReader.cs
@@ -0,0 +1,159 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Serialize
+{
+    using System;
+    using System.Collections;
+    using System.Reflection;
+    using System.Xml;
+
+    /// <summary>
+    /// Class used for reading XML files in to the CodeDom.
+    /// </summary>
+    public class CodeDomReader
+    {
+        private Assembly[] assemblies;
+
+        /// <summary>
+        /// Creates a new CodeDomReader, using the current assembly.
+        /// </summary>
+        public CodeDomReader()
+        {
+            this.assemblies = new Assembly[] { Assembly.GetExecutingAssembly() };
+        }
+
+        /// <summary>
+        /// Creates a new CodeDomReader, and takes in a list of assemblies in which to
+        /// look for elements.
+        /// </summary>
+        /// <param name="assemblies">Assemblies in which to look for types that correspond 
+        /// to elements.</param>
+        public CodeDomReader(Assembly[] assemblies)
+        {
+            this.assemblies = assemblies;
+        }
+
+        /// <summary>
+        /// Loads an XML file into a strongly-typed code dom.
+        /// </summary>
+        /// <param name="filePath">File to load into the code dom.</param>
+        /// <returns>The strongly-typed object at the root of the tree.</returns>
+        public ISchemaElement Load(string filePath)
+        {
+            XmlDocument document = new XmlDocument();
+            document.Load(filePath);
+            ISchemaElement schemaElement = null;
+
+            foreach (XmlNode node in document.ChildNodes)
+            {
+                XmlElement element = node as XmlElement;
+                if (element != null)
+                {
+                    if (schemaElement != null)
+                    {
+                        throw new InvalidOperationException("Multiple root elements found in file.");
+                    }
+
+                    schemaElement = this.CreateObjectFromElement(element);
+                    this.ParseObjectFromElement(schemaElement, element);
+                }
+            }
+            return schemaElement;
+        }
+
+        /// <summary>
+        /// Parses an ISchemaElement from the XmlElement.
+        /// </summary>
+        /// <param name="schemaElement">ISchemaElement to fill in.</param>
+        /// <param name="element">XmlElement to parse from.</param>
+        private void ParseObjectFromElement(ISchemaElement schemaElement, XmlElement element)
+        {
+            foreach (XmlAttribute attribute in element.Attributes)
+            {
+                this.SetAttributeOnObject(schemaElement, attribute.LocalName, attribute.Value);
+            }
+
+            foreach (XmlNode node in element.ChildNodes)
+            {
+                XmlElement childElement = node as XmlElement;
+                if (childElement != null)
+                {
+                    ISchemaElement childSchemaElement = null;
+                    ICreateChildren createChildren = schemaElement as ICreateChildren;
+                    if (createChildren == null)
+                    {
+                        throw new InvalidOperationException("ISchemaElement with name " + element.LocalName + " does not implement ICreateChildren.");
+                    }
+                    else
+                    {
+                        childSchemaElement = createChildren.CreateChild(childElement.LocalName);
+                    }
+
+                    if (childSchemaElement == null)
+                    {
+                        childSchemaElement = this.CreateObjectFromElement(childElement);
+                        if (childSchemaElement == null)
+                        {
+                            throw new InvalidOperationException("XmlElement with name " + childElement.LocalName + " does not have a corresponding ISchemaElement.");
+                        }
+                    }
+
+                    this.ParseObjectFromElement(childSchemaElement, childElement);
+                    IParentElement parentElement = (IParentElement)schemaElement;
+                    parentElement.AddChild(childSchemaElement);
+                }
+                else
+                {
+                    XmlText childText = node as XmlText;
+                    if (childText != null)
+                    {
+                        this.SetAttributeOnObject(schemaElement, "Content", childText.Value);
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Sets an attribute on an ISchemaElement.
+        /// </summary>
+        /// <param name="schemaElement">Schema element to set attribute on.</param>
+        /// <param name="name">Name of the attribute to set.</param>
+        /// <param name="value">Value to set on the attribute.</param>
+        private void SetAttributeOnObject(ISchemaElement schemaElement, string name, string value)
+        {
+            ISetAttributes setAttributes = schemaElement as ISetAttributes;
+            if (setAttributes == null)
+            {
+                throw new InvalidOperationException("ISchemaElement with name " 
+                    + schemaElement.GetType().FullName.ToString() 
+                    + " does not implement ISetAttributes.");
+            }
+            else
+            {
+                setAttributes.SetAttribute(name, value);
+            }
+        }
+
+        /// <summary>
+        /// Creates an object from an XML element by digging through the assembly list.
+        /// </summary>
+        /// <param name="element">XML Element to create an ISchemaElement from.</param>
+        /// <returns>A constructed ISchemaElement.</returns>
+        private ISchemaElement CreateObjectFromElement(XmlElement element)
+        {
+            ISchemaElement schemaElement = null;
+            foreach (Assembly assembly in this.assemblies)
+            {
+                foreach (Type type in assembly.GetTypes())
+                {
+                    if (type.FullName.EndsWith(element.LocalName) 
+                        && typeof(ISchemaElement).IsAssignableFrom(type))
+                    {
+                        schemaElement = (ISchemaElement)Activator.CreateInstance(type);
+                    }
+                }
+            }
+            return schemaElement;
+        }
+    }
+}