MetaTableHelper.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / DynamicData / DynamicData / Util / MetaTableHelper.cs / 1305376 / MetaTableHelper.cs
                        
                        
                            namespace System.Web.DynamicData.Util { 
    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.Diagnostics; 
    using System.Globalization;
    using System.Linq; 
    using System.Reflection; 
    using System.Web.Resources;
    using System.Web.UI; 
    using System.ComponentModel;
#if !ORYX_VNEXT
    using IDataBoundControlInterface = System.Web.UI.WebControls.IDataBoundControl;
#else 
    using IDataBoundControlInterface = IDataBoundControl;
    using Microsoft.Web.Data.UI.WebControls.Expressions; 
#endif 

    internal static class MetaTableHelper { 

        private static object s_mappingKey = new object();

        internal static Dictionary GetMapping(HttpContextBase httpContext) { 
            Dictionary mapping = httpContext.Items[s_mappingKey] as Dictionary;
            if (mapping == null) { 
                mapping = new Dictionary(); 
                httpContext.Items[s_mappingKey] = mapping;
            } 
            return mapping;
        }

        ///  
        /// Gets a table from the mapping. Does not throw.
        ///  
        internal static MetaTable GetTableFromMapping(HttpContextBase httpContext, object control) { 
            IDictionary mapping = GetMapping(httpContext);
            // don't throw if no mapping found 
            MappingInfo mappingInfo;
            if (mapping.TryGetValue(control, out mappingInfo)) {
                return mappingInfo.Table;
            } 
            return null;
        } 
 
        private static MappingInfo GetMappingInfo(object control, HttpContextBase httpContext) {
            IDictionary mapping = GetMapping(httpContext); 
            MappingInfo mappingInfo;
            if (!mapping.TryGetValue(control, out mappingInfo)) {
                mappingInfo = new MappingInfo();
                mapping[control] = mappingInfo; 
            }
            return mappingInfo; 
        } 

        internal static void SetTableInMapping(HttpContextBase httpContext, object control, MetaTable table, IDictionary defaultValues) { 
            MappingInfo mappingInfo = GetMappingInfo(control, httpContext);
            mappingInfo.Table = table;
            if (defaultValues != null) {
                mappingInfo.DefaultValueMapping = new DefaultValueMapping(defaultValues); 
            }
        } 
 
        internal static MetaTable GetTableWithFullFallback(IDataSource dataSource, HttpContextBase context) {
            MetaTable table = GetTableFromMapping(context, dataSource); 
            if (table != null) {
                return table;
            }
 
            IDynamicDataSource dynamicDataSource = dataSource as IDynamicDataSource;
            if (dynamicDataSource != null) { 
                table = GetTableFromDynamicDataSource(dynamicDataSource); 
                if (table != null) {
                    return table; 
                }
            }

            table = DynamicDataRouteHandler.GetRequestMetaTable(context); 
            if (table != null) {
                return table; 
            } 

            Control c = dataSource as Control; 
            string id = (c != null ? c.ID : String.Empty);
            throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture,
                "Could not determine a MetaTable. A MetaTable could not be determined for the data source '{0}' and one could not be inferred from the request URL. Make sure that the table is mapped to the dats source, or that the data source is configured with a valid context type and table name, or that the request is part of a registered DynamicDataRoute.",
                id)); 
        }
 
        internal static MetaTable GetMetaTableFromObject(object dataSource) { 
            IEnumerable enumerable = dataSource as IEnumerable;
            if (enumerable == null) { 
                return null;
            }

            // Use the first item to determine the type 
            //
            foreach (object o in enumerable) { 
                if (o != null) { 
                    return MetaTable.GetTable(o.GetType());
                } 
            }

            return null;
        } 

        /// Gets a table from an IDynamicDataSource's ContextType and EntitySetName. 
        /// Does not throw, returns null on failure. 
        internal static MetaTable GetTableFromDynamicDataSource(IDynamicDataSource dynamicDataSource) {
            string tableName = dynamicDataSource.EntitySetName; 
            Type contextType = dynamicDataSource.ContextType;
            if (contextType == null || String.IsNullOrEmpty(tableName)) {
                return null;
            } 

 
            MetaModel model; 
            if (MetaModel.MetaModelManager.TryGetModel(contextType, out model)) {
                Debug.Assert(model != null); 
                MetaTable table;
                if (model.TryGetTable(tableName, out table)) {
                    return table;
                } 
            }
 
            return null; 
        }
 
        internal static MetaTable FindMetaTable(Control current) {
            return FindMetaTable(current, HttpContext.Current.ToWrapper());
        }
 
        internal static DefaultValueMapping GetDefaultValueMapping(Control current, HttpContextBase context) {
            IDictionary mapping = GetMapping(context); 
            if (!(current is INamingContainer)) { 
                current = current.NamingContainer;
            } 

            for (; current != null; current = current.NamingContainer) {
                MappingInfo mappingInfo;
                // If we find a mapping then return that value 
                if (mapping.TryGetValue(current, out mappingInfo)) {
                    return mappingInfo.DefaultValueMapping; 
                } 
            }
            return null; 
        }

        internal static MetaTable FindMetaTable(Control current, HttpContextBase context) {
            MetaTable table = null; 
            // Start from the first naming container
            if (!(current is INamingContainer)) { 
                current = current.NamingContainer; 
            }
            for (; current != null; current = current.NamingContainer) { 
                // Find the first table mapped to a control
                table = GetTableFromMapping(context, current);
                if (table != null) {
                    return table; 
                }
 
                IDataBoundControlInterface dataBoundControl = DataControlHelper.GetDataBoundControl(current, false /*failIfNotFound*/); 

                // Not a data control: continue searching 
                if (dataBoundControl == null) {
                    continue;
                }
 
                IDataSource dataSourceControl = dataBoundControl.DataSourceObject;
                // Check if it's associated with a DataSource or can be retrieved from the current route 
                if (dataSourceControl != null) { 
                    return GetTableWithFullFallback(dataSourceControl, context);
                } 

                // Check if it has a datasource (i.e. not a control, but directly some data)
                object dataSource = dataBoundControl.DataSource;
                if (dataSource != null) { 
                    // Try to get a MetaTable from it.  If so, we're done
                    table = GetMetaTableFromObject(dataSource); 
                    if (table != null) { 
                        return table;
                    } 
                }
            }

            return null; 
        }
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
MetaTableHelper.cs source code in C# .NET

Source code for the .NET framework in C#

Code:

Link Menu
