Add UtcNow, RandGuid support to SystemBindingData

src/Microsoft.Azure.WebJobs.Host/Bindings/BindingDataPathHelper.cs

@@ -18,9 +18,14 @@ internal static class BindingDataPathHelper
         /// strings, JToken, and Guid (which is translated in canonical form without curly braces).
         /// </summary>
         /// <param name="parameterValue">The parameter value to convert</param>
+        /// <param name="format">Optional format string</param>
         /// <returns>Path compatible string representation of the given parameter or null if its type is not supported.</returns>
-        public static string ConvertParameterValueToString(object parameterValue)
+        public static string ConvertParameterValueToString(object parameterValue, string format = null)
         {
+            if (string.IsNullOrWhiteSpace(format))
+            {
+                format = null; // normalize. 
+            }
             if (parameterValue != null)
             {
                 switch (Type.GetTypeCode(parameterValue.GetType()))
@@ -45,10 +50,21 @@ public static string ConvertParameterValueToString(object parameterValue)
                         return ((Byte)parameterValue).ToString(CultureInfo.InvariantCulture);
                     case TypeCode.SByte:
                         return ((SByte)parameterValue).ToString(CultureInfo.InvariantCulture);
+                    case TypeCode.DateTime:                        
+                        format = format ?? "yyyy-MM-ddTHH-mm-ssK"; // default to ISO 8601
+                        var dateTime = (DateTime)parameterValue;
+                        return dateTime.ToString(format, CultureInfo.InvariantCulture);
                     case TypeCode.Object:
                         if (parameterValue is Guid)
                         {
-                            return parameterValue.ToString();
+                            if (format == null)
+                            {
+                                return parameterValue.ToString();
+                            }
+                            else
+                            {
+                                return ((Guid)parameterValue).ToString(format, CultureInfo.InvariantCulture);
+                            }
                         }
                         if (parameterValue is Newtonsoft.Json.Linq.JToken)
                         {

src/Microsoft.Azure.WebJobs.Host/Bindings/Path/BindingParameterResolver.cs

@@ -8,6 +8,11 @@
 
 namespace Microsoft.Azure.WebJobs.Host.Bindings.Path
 {
+    /// <summary>
+    /// Support for adding built-in values to binding data. 
+    /// Don't add new resolvers here. Instead, add it to <see cref="SystemBindingData"/>
+    /// </summary>
+    [Obsolete("Use SystemBindingData instead")]
     internal abstract class BindingParameterResolver
     {
         private static Collection<BindingParameterResolver> _resolvers;
@@ -69,6 +74,7 @@ protected string GetFormatOrNull(string value)
             return null;
         }
 
+        // This is an alias for 'sys.randguid'
         private class RandGuidResolver : BindingParameterResolver
         {
             public override string Name
@@ -82,18 +88,14 @@ public override string Name
             public override string Resolve(string value)
             {
                 string format = GetFormatOrNull(value);
-
-                if (!string.IsNullOrEmpty(format))
-                {
-                    return Guid.NewGuid().ToString(format, CultureInfo.InvariantCulture);
-                }
-                else
-                {
-                    return Guid.NewGuid().ToString();
-                }
+                var val = new SystemBindingData().RandGuid;
+                return BindingDataPathHelper.ConvertParameterValueToString(val, format);                
             }
         }
 
+        // This can't be aliases to 'sys.UtcNow' because
+        // 'sys.UtcNow' always resolves to DateTime.UtcNow. 
+        // But 'datetime' may either resolve to user bidning data or to DateTime.UtcNow.        
         private class DateTimeResolver : BindingParameterResolver
         {
             public override string Name
@@ -107,16 +109,8 @@ public override string Name
             public override string Resolve(string value)
             {
                 string format = GetFormatOrNull(value);
-
-                if (!string.IsNullOrEmpty(format))
-                {
-                    return DateTime.UtcNow.ToString(format, CultureInfo.InvariantCulture);
-                }
-                else
-                {
-                    // default to ISO 8601
-                    return DateTime.UtcNow.ToString("yyyy-MM-ddTHH-mm-ssK", CultureInfo.InvariantCulture);
-                }
+                var val = new SystemBindingData().UtcNow;
+                return BindingDataPathHelper.ConvertParameterValueToString(val, format);
             }
         }
     }

src/Microsoft.Azure.WebJobs.Host/Bindings/Path/BindingTemplateToken.cs

@@ -37,15 +37,27 @@ public static BindingTemplateToken NewLiteral(string literalValue)
 
         public static BindingTemplateToken NewExpression(string expression)
         {
+            // BindingData takes precedence over builtins.  
+            BindingParameterResolver builtin;
+            BindingParameterResolver.TryGetResolver(expression, out builtin);
+
+            // check for formatter, which is applied to finale results. 
+            string format = null;
+            if (builtin == null)
+            {
+                int indexColon = expression.IndexOf(':');
+                if (indexColon > 0)
+                {
+                    format = expression.Substring(indexColon + 1);
+                    expression = expression.Substring(0, indexColon);
+                }
+            }
+
             if (!BindingTemplateParser.IsValidIdentifier(expression))
             {
                 throw new FormatException($"Invalid template expression '{expression}");
             }
 
-            // BindingData takes precedence over builtins.  
-            BindingParameterResolver builtin;
-            BindingParameterResolver.TryGetResolver(expression, out builtin);
-
             // Expression is just a series of dot operators like:  a.b.c
             var parts = expression.Split('.');
 
@@ -66,7 +78,7 @@ public static BindingTemplateToken NewExpression(string expression)
                 }
             }
 
-            return new ExpressionToken(parts, builtin);            
+            return new ExpressionToken(parts, format, builtin);            
         }
 
         public abstract string Evaluate(IReadOnlyDictionary<string, object> bindingData);
@@ -134,13 +146,16 @@ private class ExpressionToken : BindingTemplateToken
             // If non-null, then this could be a builtin object. 
             private readonly BindingParameterResolver _builtin;
 
+            private readonly string _format;
+
             // The parts of an expression, like a.b.c.
             private readonly string[] _expressionParts;
 
-            public ExpressionToken(string[] expressionParts, BindingParameterResolver builtin)
+            public ExpressionToken(string[] expressionParts, string format, BindingParameterResolver builtin)
             {
                 _expressionParts = expressionParts;
                 _builtin = builtin;
+                _format = format;
             }
 
             public override string AsLiteral => null;
@@ -198,7 +213,7 @@ public override string Evaluate(IReadOnlyDictionary<string, object> bindingData)
                     }
                 }
 
-                var strValue = BindingDataPathHelper.ConvertParameterValueToString(current);
+                var strValue = BindingDataPathHelper.ConvertParameterValueToString(current, _format);
                 return strValue;
             }
 

src/Microsoft.Azure.WebJobs.Host/Bindings/SystemBindingData.cs

@@ -20,6 +20,7 @@ internal class SystemBindingData
         public const string Name = "sys";
 
         // An internal name for this binding that uses characters that gaurantee it can't be overwritten by a user. 
+        // This is never seen by the user. 
         // This ensures that we can always unambiguously retrieve this later. 
         private const string InternalKeyName = "$sys";
 
@@ -34,6 +35,16 @@ internal class SystemBindingData
         /// </summary>
         public string MethodName { get; set; }
 
+        /// <summary>
+        /// Get the current UTC date. 
+        /// </summary>
+        public DateTime UtcNow => DateTime.UtcNow;
+
+        /// <summary>
+        /// Return a new random guid. This create a new guid each time it's called.
+        /// </summary>
+        public Guid RandGuid => Guid.NewGuid();  
+
         // Given a full bindingData, create a binding data with just the system object .
         // This can be used when resolving default contracts that shouldn't be using an instance binding data. 
         internal static IReadOnlyDictionary<string, object> GetSystemBindingData(IReadOnlyDictionary<string, object> bindingData)

src/Microsoft.Azure.WebJobs.Host/GlobalSuppressions.cs

@@ -78,4 +78,6 @@
 [assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1062:Validate arguments of public methods", MessageId = "2", Scope = "member", Target = "Microsoft.Azure.WebJobs.DefaultResolutionPolicy.#TemplateBind(System.Reflection.PropertyInfo,System.Attribute,Microsoft.Azure.WebJobs.Host.Bindings.Path.BindingTemplate,System.Collections.Generic.IReadOnlyDictionary`2<System.String,System.Object>)")]
 [assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors", Scope = "member", Target = "Microsoft.Azure.WebJobs.Host.PropertyHelper.#.ctor(System.Reflection.PropertyInfo)")]
 [assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1800:DoNotCastUnnecessarily", Scope = "member", Target = "Microsoft.Azure.WebJobs.Host.Bindings.SysBindingData.#GetFromData(System.Collections.Generic.IReadOnlyDictionary`2<System.String,System.Object>)")]
-[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1800:DoNotCastUnnecessarily", Scope = "member", Target = "Microsoft.Azure.WebJobs.Host.Bindings.SystemBindingData.#GetFromData(System.Collections.Generic.IReadOnlyDictionary`2<System.String,System.Object>)")]
+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1800:DoNotCastUnnecessarily", Scope = "member", Target = "Microsoft.Azure.WebJobs.Host.Bindings.SystemBindingData.#GetFromData(System.Collections.Generic.IReadOnlyDictionary`2<System.String,System.Object>)")]
+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Scope = "member", Target = "Microsoft.Azure.WebJobs.Host.Bindings.SystemBindingData.#UtcNow")]
+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Scope = "member", Target = "Microsoft.Azure.WebJobs.Host.Bindings.SystemBindingData.#RandGuid")]

test/Microsoft.Azure.WebJobs.Host.UnitTests/Bindings/BindingDataPathHelperTests.cs

@@ -70,10 +70,10 @@ public void ConvertParamValueToString_IfGuidParam_ReturnsStringValue()
         public void ConvertParamValueToString_IfUnupportedType_ReturnsNull()
         {
             // Arrange
-            DateTime dateTimeParam = DateTime.Now;
+            var obj = new { value = 12 };  
 
             // Act
-            string stringParamValue = BindingDataPathHelper.ConvertParameterValueToString(dateTimeParam);
+            string stringParamValue = BindingDataPathHelper.ConvertParameterValueToString(obj);
 
             // Assert
             Assert.Null(stringParamValue);

test/Microsoft.Azure.WebJobs.Host.UnitTests/Bindings/Path/BindingTemplateTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
@@ -9,6 +10,7 @@
 using Xunit;
 using Xunit.Extensions;
 using Newtonsoft.Json.Linq;
+using System.Globalization;
 
 namespace Microsoft.Azure.WebJobs.Host.UnitTests.Bindings.Path
 {
@@ -319,5 +321,46 @@ public void FromString_IgnoreCase_CreatesCaseInsensitiveTemplate()
             result = template.Bind(parameters);
             Assert.Equal("A/TestB/TestC", result);
         }
+
+
+        [Fact]
+        public void GuidFormats()
+        {
+            var g = Guid.NewGuid();
+            var parameters = new Dictionary<string, object>
+                {
+                    { "g", g }
+                };
+
+            foreach (var format in new string[] { "N", "D", "B", "P", "X", "" })
+            {
+
+                BindingTemplate template = BindingTemplate.FromString(@"{g:" + format + "}");       
+
+                string expected = g.ToString(format, CultureInfo.InvariantCulture);
+                string result = template.Bind(parameters);
+
+                Assert.Equal(expected, result);
+            }
+        }
+
+        [Fact]
+        public void DateTimeFormats()
+        {
+            var dt = DateTime.UtcNow;
+            var parameters = new Dictionary<string, object>
+                {
+                    { "dt",dt }
+                };
+
+
+            var format = "YYYYMMdd";
+            BindingTemplate template = BindingTemplate.FromString(@"{dt:" + format + "}");
+
+            string expected = dt.ToString(format, CultureInfo.InvariantCulture);
+            string result = template.Bind(parameters);
+
+            Assert.Equal(expected, result);            
+        }
     }
 }

test/Microsoft.Azure.WebJobs.Host.UnitTests/Common/BindToGenericItemTests.cs

@@ -79,16 +79,32 @@ public void Initialize(ExtensionConfigContext context)
             public void Test(TestJobHost<ConfigTestDefaultToMethodName> host)
             {
                 host.Call("Func", new { k = 1 });
-                Assert.Equal("1", _log);
+                Assert.NotNull(_log);
 
                 host.Call("Func2", new { k = 1 });
                 Assert.Equal("Func2", _log);
             }
 
             string _log;
 
-            public void Func([Test2(Path = "{k}")] string w)
+            public void Func([Test2(Path = "{k}*{sys.randGuid:N}*{sys.randGuid:B}*{sys.UtcNow:yyyy}")] string w)
             {
+                var parts = w.Split('*');
+                string k = parts[0];
+                Assert.Equal("1", k);
+
+                string guidstr1 = parts[1];
+                var guid1 = Guid.Parse(guidstr1);
+                string guidstr2 = parts[2];
+                var guid2 = Guid.Parse(guidstr2);                
+
+                Assert.Equal(guid1.ToString("N"), guidstr1);
+                Assert.Equal(guid2.ToString("B"), guidstr2);
+                Assert.NotEqual(guid1, guid2); // each sys.RandGuid is a different value 
+
+                string date = parts[3];
+                Assert.Equal(DateTime.UtcNow.Year.ToString(), date);
+
                 _log = w;
             }