Object Explorer Service (#311)

* moving OE service from an old branch

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Contracts/CreateSessionRequest.cs

@@ -0,0 +1,45 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Connection.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Contracts
+{
+    /// <summary>
+    /// Information returned from a <see cref="CreateSessionRequest"/>.
+    /// Contains success information, a <see cref="SessionId"/> to be used when
+    /// requesting expansion of nodes, and a root node to display for this area.
+    /// </summary>
+    public class CreateSessionResponse
+    {
+        /// <summary>
+        /// Boolean indicating if the connection was successful
+        /// </summary>
+        public bool Success { get; set; }
+
+        /// <summary>
+        /// Unique ID to use when sending any requests for objects in the
+        /// tree under the node
+        /// </summary>
+        public string SessionId { get; set; }
+
+        /// <summary>
+        /// Information describing the base node in the tree
+        /// </summary>
+        public NodeInfo RootNode { get; set; }
+    }
+    /// <summary>
+    /// Establishes an Object Explorer tree session for a specific connection.
+    /// This will create a connection to a specific server or database, register
+    /// it for use in the 
+    /// </summary>
+    public class CreateSessionRequest
+    {
+        public static readonly
+            RequestType<ConnectionDetails, CreateSessionResponse> Type =
+            RequestType<ConnectionDetails, CreateSessionResponse>.Create("objectexplorer/createsession");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Contracts/ExpandRequest.cs

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+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Contracts
+{
+    /// <summary>
+    /// Information returned from a <see cref="ExpandRequest"/>.
+    /// </summary>
+    public class ExpandResponse
+    {
+        /// <summary>
+        /// Unique ID to use when sending any requests for objects in the
+        /// tree under the node
+        /// </summary>
+        public string SessionId { get; set; }
+
+        /// <summary>
+        /// Information describing the expanded nodes in the tree
+        /// </summary>
+        public NodeInfo[] Nodes { get; set; }
+    }
+
+    /// <summary>
+    /// Parameters to the <see cref="ExpandRequest"/>.
+    /// </summary>
+    public class ExpandParams
+    {
+        /// <summary>
+        /// The Id returned from a <see cref="CreateSessionRequest"/>. This
+        /// is used to disambiguate between different trees. 
+        /// </summary>
+        public string SessionId { get; set; }
+
+        /// <summary>
+        /// Path identifying the node to expand. See <see cref="NodeInfo.NodePath"/> for details
+        /// </summary>
+        public string NodePath { get; set; }
+    }
+
+    /// <summary>
+    /// A request to expand a 
+    /// </summary>
+    public class ExpandRequest
+    {
+        /// <summary>
+        /// Returns children of a given node as a <see cref="NodeInfo"/> array.
+        /// </summary>
+        public static readonly
+            RequestType<ExpandParams, ExpandResponse> Type =
+            RequestType<ExpandParams, ExpandResponse>.Create("objectexplorer/expand");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Contracts/NodeInfo.cs

@@ -0,0 +1,40 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Contracts
+{
+    /// <summary>
+    /// Information describing a Node in the Object Explorer tree. 
+    /// Contains information required to display the Node to the user and
+    /// to know whether actions such as expanding children is possible
+    /// the node 
+    /// </summary>
+    public class NodeInfo
+    {
+        /// <summary>
+        /// Path identifying this node: for example a table will be at ["server", "database", "tables", "tableName"].
+        /// This enables rapid navigation of the tree without the need for a global registry of elements.
+        /// The path functions as a unique ID and is used to disambiguate the node when sending requests for expansion.
+        /// A common ID is needed since processes do not share address space and need a unique identifier
+        /// </summary>
+        public string NodePath { get; set; }
+
+        /// <summary>
+        /// The type of the node - for example Server, Database, Folder, Table
+        /// </summary>
+        public string NodeType { get; set; }
+
+        /// <summary>
+        /// Label to display to the user, describing this node.
+        /// </summary>
+        public string Label { get; set; }
+
+        /// <summary>
+        /// Is this a leaf node (in which case no children can be generated) or
+        /// is it expandable?
+        /// </summary>
+        public bool IsLeaf { get; set; }
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/ObjectExplorer/Contracts/RefreshRequest.cs

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+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.ObjectExplorer.Contracts
+{
+    /// <summary>
+    /// Parameters to the <see cref="ExpandRequest"/>.
+    /// </summary>
+    public class RefreshParams
+    {
+        /// <summary>
+        /// The Id returned from a <see cref="CreateSessionRequest"/>. This
+        /// is used to disambiguate between different trees. 
+        /// </summary>
+        public string SessionId { get; set; }
+
+        /// <summary>
+        /// Path identifying the node to expand. See <see cref="NodeInfo.NodePath"/> for details
+        /// </summary>
+        public string[] NodePath { get; set; }
+    }
+
+    /// <summary>
+    /// A request to expand a 
+    /// </summary>
+    public class RefreshRequest
+    {
+        /// <summary>
+        /// Returns children of a given node as a <see cref="NodeInfo"/> array.
+        /// </summary>
+        public static readonly
+            RequestType<ExpandParams, NodeInfo[]> Type =
+            RequestType<ExpandParams, NodeInfo[]>.Create("objectexplorer/refresh");
+    }
+}