Started the functionality for opening shader code in user set, text editor

ShaderGraph/com.unity.shadergraph/Editor/Drawing/MaterialGraphEditWindow.cs

 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Text;
 using UnityEditor.Graphing;
+using UnityEditorInternal;
+using Debug = UnityEngine.Debug;
 using Object = UnityEngine.Object;
 using Edge = UnityEditor.Experimental.UIElements.GraphView.Edge;
 #if UNITY_2018_1
                     m_GraphEditorView.saveRequested += UpdateAsset;
                     m_GraphEditorView.convertToSubgraphRequested += ToSubGraph;
                     m_GraphEditorView.showInProjectRequested += PingAsset;
+                    m_GraphEditorView.showGeneratedCode += ShowGeneratedCode;
                     this.GetRootVisualContainer().Add(graphEditorView);
                 }
             }
                     materialGraphEditWindow.Rebuild();
                 }
             }
+        }
+
+        public void ShowGeneratedCode()
+        {
+
+            var asset = AssetDatabase.LoadAssetAtPath<Object>(AssetDatabase.GUIDToAssetPath(selectedGuid));
+
+            Debug.Log(asset.name);
+            string path = String.Format("Temp/GeneratedFromGraph-{0}.shader", asset.name);
+            //Debug.Log(path);
+
+            WriteStringToFile(path);
+
+            /*
+            if (!WriteStringToFile(compiledShader, path, kNotAtomic, kFileFlagDontIndex | kFileFlagTemporary))
+                return;
+
+            path = PathToAbsolutePath(path);
+            if (!OpenScriptFile(path, 0))
+                WarningStringWithoutStacktrace("Unable to open " + path + ": Check external editor in preferences");
+            */
+
+            //core::string path = Format("Temp/GeneratedFromSurface-%s.shader", shader->GetOutputFilename().c_str());
+        }
+
+        private void WriteStringToFile(string path)
+        {
+            List<PropertyCollector.TextureInfo> textureInfo;
+            var graphView = graphEditorView.graphView;
+
+            foreach (AbstractMaterialNode node in graphView.graph.GetNodes<AbstractMaterialNode>())
+            {
+                var masterNode = node as IMasterNode;
+                if (masterNode != null)
+                {
+                    Debug.Log(path);
+                    var shader = masterNode.GetShader(GenerationMode.ForReals, node.name, out textureInfo);
+                    Debug.Log(shader);
+                    //GUIUtility.systemCopyBuffer = shader;
+                    File.WriteAllText(path, shader);
+
+
+
+
+                    Debug.Log(ScriptEditorUtility.GetExternalScriptEditor());
+
+
+
+                    string file = Path.GetFullPath(path);
+                    ProcessStartInfo pi = new ProcessStartInfo(file);
+                    pi.Arguments = Path.GetFileName(file);
+                    pi.UseShellExecute = true;
+                    pi.WorkingDirectory = Path.GetDirectoryName(file);
+                    pi.FileName = ScriptEditorUtility.GetExternalScriptEditor();
+                    pi.Verb = "OPEN";
+                    Process.Start(pi);
+                }
+            }
+//            var nodes = graphView.selection.OfType<MaterialNodeView>().Where(x => (x.node is AbstractMaterialNode));
+//            Debug.Log(nodes.Length);
+//            foreach (var node in nodes)
+//            {
+//                var masterNode = node as IMasterNode;
+//                if (masterNode != null)
+//                {
+//                    Debug.Log(path);
+//                    var shader = masterNode.GetShader(GenerationMode.ForReals, node.name, out textureInfo);
+//                    Debug.Log(shader);
+//                    //GUIUtility.systemCopyBuffer = shader;
+//                    File.WriteAllText(path, shader);
+//                //}
+//            }
+
+
+
+
+            //File tmpFile = new File;
+
+//            else if (atomicMode == kNotAtomic)
+//            {
+//                DeleteFile(path);
+//                tmpFilePath = path;
+//            }
         }
 
         public void ToSubGraph()

ShaderGraph/com.unity.shadergraph/Editor/Drawing/Views/GraphEditorView.cs

 
         public Action showInProjectRequested { get; set; }
 
+        public Action showGeneratedCode { get; set; }
+
         public MaterialGraphView graphView
         {
             get { return m_GraphView; }
                 {
                     if (showInProjectRequested != null)
                         showInProjectRequested();
+                }
+                GUILayout.Space(6);
+                if (GUILayout.Button("Show Generated Code", EditorStyles.toolbarButton))
+                {
+                    if (showGeneratedCode != null)
+                        showGeneratedCode();
                 }
                 GUILayout.FlexibleSpace();
                 GUILayout.EndHorizontal();