Provide format output parameter

src/CLU/Commands.ScenarioTests.ResourceManager.Common/Mocks/MockCommandRuntime.cs

@@ -20,6 +20,7 @@
 using System.Globalization;
 using System.Management.Automation;
 using System.Management.Automation.Host;
+using Microsoft.CLU;
 
 namespace Microsoft.Azure.Commands.Common.Test.Mocks
 {
@@ -285,6 +286,8 @@ public override Version Version
                 }
             }
 
+            public override OutputFormat RequestedOutputFormat { get; set;  }
+
             class MockPSHostUI : PSHostUserInterface
             {
                 public override Dictionary<string, PSObject> Prompt(string caption, string message, Collection<FieldDescription> descriptions)

src/CLU/Microsoft.CLU.Test/StringGenerator.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+using System.Management.Automation;
+
+namespace Microsoft.CLU.Test
+{
+    [Cmdlet(VerbsCommon.New, "String")]
+    public class StringGenerator : PSCmdlet
+    {
+        public StringGenerator()
+        {
+            Count = 10;
+            StringFormat = "String {0}";
+        }
+
+        [Parameter()]
+        public int Count { get; set; }
+
+        [Parameter()]
+        public string StringFormat { get; set; }
+
+        protected override void ProcessRecord()
+        {
+            base.ProcessRecord();
+            for (int i = 1; i <= Count; ++i)
+            {
+                WriteObject(String.Format(StringFormat, i));
+            }
+        }
+
+    }
+}

src/CLU/Microsoft.CLU/CommandModel/CmdletCommandModel.cs

@@ -43,7 +43,7 @@ public CommandModelErrorCode Run(ConfigurationDictionary commandConfiguration, s
             // The runtime host is a Cmdlet's path to accessing system features, such as Console I/O
             // and session state. The runtime instance is created here and passed into the binder,
             // which will be creating the Cmdlet instance.
-            var runtimeHost = new System.Management.Automation.Host.CLUHost(arguments, hostStreamInfo);
+            var runtimeHost = new System.Management.Automation.Host.CLUHost(ref arguments, hostStreamInfo);
 
             // Create instance of ICommandBinder and ICommand implementation for cmdlet model
             var binderAndCommand = new CmdletBinderAndCommand(commandConfiguration, runtimeHost);

src/CLU/Microsoft.CLU/System.Management.Automation/CLUHost.cs

@@ -22,7 +22,7 @@ internal class CLUHost : PSHost, ICommandRuntime
         /// Creates an instance of CLUHost.
         /// </summary>
         /// <param name="args">The commandline arguments</param>
-        internal CLUHost(string[] args, HostStreamInfo hostStreamInfo)
+        internal CLUHost(ref string[] args, HostStreamInfo hostStreamInfo)
         {
             Debug.Assert(args != null);
             Debug.Assert(hostStreamInfo != null);
@@ -37,12 +37,29 @@ internal CLUHost(string[] args, HostStreamInfo hostStreamInfo)
             if (!string.IsNullOrEmpty(vpref))
                 _doVerbose = InterpretStreamPreference(Constants.VerbosePreference, vpref, _doVerbose);
 
+            var argList = args.ToList();
+
             // Command-line switch overrides environment variable
-            if (args.Select(arg => arg.ToLowerInvariant()).Where(arg => arg.Equals("--debug") || arg.Equals("/debug")).Any())
+            if (RemoveArgumentIfFound(argList, "debug"))
+            {
                 _doDebug = Constants.CmdletPreferencesInquire;
-
-            if (args.Select(arg => arg.ToLowerInvariant()).Where(arg => arg.Equals("--verbose") || arg.Equals("/verbose")).Any())
+            }
+
+            if (RemoveArgumentIfFound(argList, "verbose"))
+            {
                 _doVerbose = Constants.CmdletPreferencesContinue;
+            }
+
+            if (RemoveArgumentIfFound(argList, "json"))
+            {
+                this.RequestedOutputFormat = OutputFormat.JSON;
+            }
+            else if (RemoveArgumentIfFound(argList, "display"))
+            {
+                this.RequestedOutputFormat = OutputFormat.Display;
+            }
+
+            args = argList.ToArray();
         }
 
         internal CLUHost(string[] args, HostStreamInfo hostStreamInfo, string debugPreference, string verbosePreference)
@@ -82,6 +99,11 @@ internal HostStreamInfo StreamInfo
         /// <remarks>If this is true, your code is not doing console I/O</remarks>
         public override bool IsInputRedirected { get { return _hostStreamInfo.IsInputRedirected; } }
 
+        /// <summary>
+        /// Command line override of requested output format...
+        /// </summary>
+        public override OutputFormat RequestedOutputFormat { get; set;  }
+
         /// <summary>
         /// Tells whether the STDOUT byte stream has been redirected to a file or pipe
         /// </summary>
@@ -514,6 +536,19 @@ private string InterpretStreamPreference(string variable, string input, string c
                 new ChoiceDescription("&Halt Command", "Stop this command.")
         };
         private HostStreamInfo _hostStreamInfo;
+        private bool RemoveArgumentIfFound(List<string> args, string argName)
+        {
+            int index = args.FindIndex(arg => arg.ToLowerInvariant().Equals($"--{argName}") || arg.ToLowerInvariant().Equals($"/{argName}"));
+            if (index > -1)
+            {
+                args.RemoveAt(index);
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
 
         #endregion
 

src/CLU/Microsoft.CLU/System.Management.Automation/Cmdlet.cs

@@ -63,8 +63,8 @@ protected void WriteObject(object sendToPipeline)
         {
             if (sendToPipeline != null)
             {
-                if (CommandRuntime.Host.IsOutputRedirected)
-                {
+                if (ShouldWriteJsonOutput())
+                { 
                     CommandRuntime.WriteObject(sendToPipeline);
                 }
                 else
@@ -78,7 +78,7 @@ protected void WriteObject(object sendToPipeline, bool enumerateCollection)
         {
             if (sendToPipeline != null)
             {
-                if (CommandRuntime.Host.IsOutputRedirected)
+                if (ShouldWriteJsonOutput())
                 {
                     CommandRuntime.WriteObject(sendToPipeline, enumerateCollection);
                 }
@@ -142,15 +142,21 @@ internal void FlushPipeline(LocalPackage package)
                     formattedType = obj.GetType();
                     if (!wroteHeader)
                     {
-                        CommandRuntime.WriteCommandDetail(view.FormatHeader(CLUEnvironment.Console.WindowWidth));
-                        CommandRuntime.WriteCommandDetail("");
+                        CommandRuntime.WriteObject(view.FormatHeader(CLUEnvironment.Console.WindowWidth));
+                        CommandRuntime.WriteObject("");
                         wroteHeader = true;
                     }
-                    CommandRuntime.WriteCommandDetail(view.FormatObject(obj));
+                    CommandRuntime.WriteObject(view.FormatObject(obj));
                 }
             }
         }
 
+        internal bool ShouldWriteJsonOutput()
+        {
+            var requestedOutputFormat = CommandRuntime.Host.RequestedOutputFormat;
+            return (CommandRuntime.Host.IsOutputRedirected && requestedOutputFormat == OutputFormat.Auto) 
+                || requestedOutputFormat == OutputFormat.JSON;
+        }
         protected void WriteProgress(ProgressRecord progressRecord) { if (progressRecord != null) CommandRuntime.WriteProgress(progressRecord); }
 
         protected void WriteVerbose(string text) { if (!string.IsNullOrEmpty(text)) CommandRuntime.WriteVerbose(text);  }

src/CLU/Microsoft.CLU/System.Management.Automation/OutputFormat.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.CLU
+{
+    public enum OutputFormat
+    {
+        Auto = 0,
+        JSON = 1,
+        Display = 2
+    }
+}

src/CLU/Microsoft.CLU/System.Management.Automation/PSHost.cs

@@ -14,5 +14,6 @@ protected PSHost() { }
         public abstract Version Version { get; }
         public abstract bool IsInputRedirected { get; }
         public abstract bool IsOutputRedirected { get; }
+        public abstract Microsoft.CLU.OutputFormat RequestedOutputFormat { get; set; }
     }
 }