Or Filtering on Object Explorer Nodes (#1608)

support for a more robust filtering system in the Object Explorer xml, allowing for or-ing filter properties together for use in URN querying for objects

Co-authored-by: Charles Gagnon <chgagnon@microsoft.com>

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Nodes/ChildFactory.cs

@@ -36,7 +36,7 @@ namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Nodes
         /// <summary>
         /// The list of filters that should be applied on the smo object list
         /// </summary>
-        public abstract IEnumerable<NodeFilter> Filters { get; }
+        public abstract IEnumerable<INodeFilter> Filters { get; }
 
         /// <summary>
         /// The list of properties to be loaded with the object

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Nodes/INodeFilter.cs

@@ -0,0 +1,57 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Collections.Generic;
+//using System.Linq;
+using System.Text;
+
+namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Nodes
+{
+    /// <summary>
+    /// Has information for filtering a SMO object by properties 
+    /// </summary>
+    public interface INodeFilter
+    {
+        /// <summary>
+        /// Returns true if the filter can be apply to the given type and Server type
+        /// </summary>
+        /// <param name="type">Type of the querier</param>
+        /// <param name="validForFlag">Server Type</param>
+        /// <returns></returns>
+        bool CanApplyFilter(Type type, ValidForFlag validForFlag);
+
+        /// <summary>
+        /// Creates a string from the filter property and values to be used in the Urn to query the SQL objects
+        /// Example of the output:[@ IsSystemObject = 0]
+        /// </summary>
+        /// <returns></returns>
+        string ToPropertyFilterString(Type type, ValidForFlag validForFlag);
+
+        /// <summary>
+        /// Creates a fully paramaterized property filter string for the URN query for SQL objects.
+        /// Example of the output:[@ IsSystemObject = 0]
+        /// </summary>
+        /// <returns></returns>
+        public static string GetPropertyFilter(IEnumerable<INodeFilter> filters, Type type, ValidForFlag validForFlag)
+        {
+            StringBuilder filter = new StringBuilder();
+            foreach (var value in filters)
+            {
+                string andPrefix = filter.Length == 0 ? string.Empty : " and ";
+                var filterString = value.ToPropertyFilterString(type, validForFlag);
+                if (filterString != string.Empty) {
+                    filter.Append($"{andPrefix}{filterString}");
+                }
+            }
+
+            if (filter.Length != 0)
+            {
+                return "[" + filter.ToString() + "]";
+            }
+            return string.Empty;
+        }
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Nodes/NodeOrFilter.cs

@@ -0,0 +1,58 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Nodes
+{
+    /// <summary>
+    /// Has information for filtering a SMO object by properties 
+    /// </summary>
+    public class NodeOrFilter : INodeFilter
+    {
+        /// <summary>
+        /// Filter values
+        /// </summary>
+        public List<NodePropertyFilter> FilterList { get; set; }
+
+        /// <summary>
+        /// Returns true if any of the filters within the FilterList apply to the type and server type.
+        /// </summary>
+        /// <param name="type">Type of the querier</param>
+        /// <param name="validForFlag">Server Type</param>
+        public bool CanApplyFilter(Type type, ValidForFlag validForFlag) {
+            return this.FilterList.Exists(f => f.CanApplyFilter(type, validForFlag));
+        }
+
+        /// <summary>
+        /// Creates a string representation of a node "or" filter, which is combined in the INodeFilter interface to construct the filter used in the URN to query the SQL objects.
+        /// Example of the output: ((@TableTemporalType = 1) or (@LedgerTableType = 1))
+        /// </summary>
+        /// <returns></returns>
+        public string ToPropertyFilterString(Type type, ValidForFlag validForFlag)
+        {
+            StringBuilder filter = new StringBuilder();
+            foreach (var nodeFilter in FilterList)
+            {
+                string orPrefix = filter.Length == 0 ? string.Empty : " or ";
+
+                // For "or" filter, have to check each node as it's processed for whether it's valid.
+                var filterString = nodeFilter.ToPropertyFilterString(type, validForFlag);
+                if (filterString != string.Empty)
+                {
+                    filter.Append($"{orPrefix}{filterString}");
+                }
+            }
+
+            if (filter.Length != 0)
+            {
+                return "(" + filter.ToString() + ")";
+            }
+            return string.Empty;
+        }
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Nodes/NodePropertyFilter.cs

@@ -5,14 +5,14 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
+using System.Text;
 
 namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Nodes
 {
     /// <summary>
     /// Has information for filtering a SMO object by properties 
     /// </summary>
-    public class NodeFilter
+    public class NodePropertyFilter : INodeFilter
     {
         /// <summary>
         /// Property name
@@ -55,52 +55,40 @@ namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Nodes
         }
 
         /// <summary>
-        /// Creates a string from the filter property and values to be used in the Urn to query the SQL objects
-        /// Example of the output:[@ IsSystemObject = 0]
+        /// Creates a string representation of a given node filter, which is combined in the INodeFilter interface to construct the filter used in the URN to query the SQL objects.
+        /// Example of the output: (@ IsSystemObject = 0)
         /// </summary>
         /// <returns></returns>
-        public string ToPropertyFilterString()
+        public string ToPropertyFilterString(Type type, ValidForFlag validForFlag)
         {
-            string filter = "";
-            List<object> values = Values;
-            if (values != null)
+            // check first if the filter can be applied; if not just return empty string
+            if (!CanApplyFilter(type, validForFlag))
             {
-                for (int i = 0; i < values.Count; i++)
+                return string.Empty;
+            }
+
+            StringBuilder filter = new StringBuilder();
+            foreach (var value in Values)
+            {
+                object propertyValue = value;
+                if (Type == typeof(string))
                 {
-                    var value = values[i];
-                    object propertyValue = value;
-                    if (Type == typeof(string))
-                    {
-                        propertyValue = $"'{propertyValue}'";
-                    }
-                    if (Type == typeof(Enum))
-                    {
-                        propertyValue = (int)Convert.ChangeType(value, Type);
-                       
-                    }
-                    string orPrefix = i == 0 ? string.Empty : "or";
-                    filter = $"{filter} {orPrefix} @{Property} = {propertyValue}";
+                    propertyValue = $"'{propertyValue}'";
                 }
+                else if (Type == typeof(Enum))
+                {
+                    propertyValue = (int)Convert.ChangeType(value, Type);
+                }
+
+                string orPrefix = filter.Length == 0 ? string.Empty : " or ";
+                filter.Append($"{orPrefix}@{Property} = {propertyValue}");
             }
-            filter = $"({filter})";
 
-            return filter;
-        }
-
-        public static string ConcatProperties(IEnumerable<NodeFilter> filters)
-        {
-            string filter = "";
-            var list = filters.ToList();
-            for (int i = 0; i < list.Count; i++)
+            if (filter.Length != 0)
             {
-                var value = list[i];
-                
-                string andPrefix = i == 0 ? string.Empty : "and";
-                filter = $"{filter} {andPrefix} {value.ToPropertyFilterString()}";
+                return "(" + filter.ToString() + ")";
             }
-            filter = $"[{filter}]";
-
-            return filter;
+            return string.Empty;
         }
     }
 }