DataSourceHelper.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Extensions / UI / WebControls / DataSourceHelper.cs / 1305376 / DataSourceHelper.cs
                        
                        
                            #if ORYX_VNEXT 
namespace Microsoft.Web.Data.UI.WebControls {
#else
namespace System.Web.UI.WebControls {
#endif 
    using System;
    using System.Collections; 
    using System.Collections.Generic; 
    using System.Collections.Specialized;
    using System.ComponentModel; 
    using System.Web;
    using System.Linq;
    using System.Web.Compilation;
    using System.Web.UI; 
    using System.Web.UI.WebControls;
    using System.Web.Resources; 
    using System.Globalization; 

    internal static class DataSourceHelper { 
        public static object SaveViewState(ParameterCollection parameters) {
            if (parameters != null) {
                return ((IStateManager)parameters).SaveViewState();
            } 
            return null;
        } 
 
        public static void TrackViewState(ParameterCollection parameters) {
            if (parameters != null) { 
                ((IStateManager)parameters).TrackViewState();
            }
        }
 
        public static IDictionary ToDictionary(this ParameterCollection parameters, HttpContext context, Control control) {
            return ToDictionary(parameters.GetValues(context, control)); 
        } 

        internal static IDictionary ToDictionary(this IOrderedDictionary parameterValues) { 
            Dictionary values = new Dictionary(parameterValues.Count, StringComparer.OrdinalIgnoreCase);

            foreach (DictionaryEntry entry in parameterValues) {
                values[(string)entry.Key] = entry.Value; 
            }
 
            return values; 
        }
 
        public static IOrderedDictionary ToCaseInsensitiveDictionary(this IDictionary dictionary) {
            if (dictionary != null) {
                IOrderedDictionary destination = new OrderedDictionary(dictionary.Count, StringComparer.OrdinalIgnoreCase);
 
                foreach (DictionaryEntry de in dictionary) {
                    destination[de.Key] = de.Value; 
                } 

                return destination; 
            }
            return null;
        }
 
        internal static object CreateObjectInstance(Type type) {
            // FastCreatePublicInstance is faster than Activator.CreateInstance since it caches the type factories. 
#if !ORYX_VNEXT 
            return HttpRuntime.FastCreatePublicInstance(type);
#else 
            return Activator.CreateInstance(type);
#endif
        }
 
        public static bool MergeDictionaries(object dataObjectType, ParameterCollection referenceValues, IDictionary source,
                               IDictionary destination, IDictionary validationErrors) { 
            return MergeDictionaries(dataObjectType, referenceValues, source, destination, null, validationErrors); 
        }
 
        public static bool MergeDictionaries(object dataObjectType, ParameterCollection reference, IDictionary source,
                                              IDictionary destination, IDictionary destinationCopy, IDictionary validationErrors) {
            if (source != null) {
                foreach (DictionaryEntry de in source) { 
                    object value = de.Value;
                    // search for a parameter that corresponds to this dictionary entry. 
                    Parameter referenceParameter = null; 
                    string parameterName = (string)de.Key;
                    foreach (Parameter p in reference) { 
                        if (String.Equals(p.Name, parameterName, StringComparison.OrdinalIgnoreCase)) {
                            referenceParameter = p;
                            break;
                        } 
                    }
                    // use the parameter for type conversion, default value and/or converting empty string to null. 
                    if (referenceParameter != null) { 
                        try {
                            value = referenceParameter.GetValue(value, true); 
                        }
                        catch (Exception e) {
                            // catch conversion exceptions so they can be handled. Note that conversion throws various
                            // types of exceptions like InvalidCastException, FormatException, OverflowException, etc. 
                            validationErrors[referenceParameter.Name] = e;
                        } 
                    } 
                    // save the value to the merged dictionaries.
                    destination[parameterName] = value; 
                    if (destinationCopy != null) {
                        destinationCopy[parameterName] = value;
                    }
                } 
            }
            return validationErrors.Count == 0; 
        } 

        public static Type GetType(string typeName) { 
            return BuildManager.GetType(typeName, true /* throwOnError */, true /* ignoreCase */);
        }

        private static object ConvertType(object value, Type type, string paramName) { 
            // NOTE: This method came from ObjectDataSource with no changes made.
            string s = value as string; 
            if (s != null) { 
                // Get the type converter for the destination type
                TypeConverter converter = TypeDescriptor.GetConverter(type); 
                if (converter != null) {
                    // Perform the conversion
                    try {
                        value = converter.ConvertFromString(s); 
                    }
                    catch (NotSupportedException) { 
                        throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture, 
                            AtlasWeb.LinqDataSourceView_CannotConvertType, paramName, typeof(string).FullName,
                            type.FullName)); 
                    }
                    catch (FormatException) {
                        throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture,
                            AtlasWeb.LinqDataSourceView_CannotConvertType, paramName, typeof(string).FullName, 
                            type.FullName));
                    } 
                } 
            }
            return value; 
        }

        public static object BuildDataObject(Type dataObjectType, IDictionary inputParameters, IDictionary validationErrors) {
            object dataObject = CreateObjectInstance(dataObjectType); 

            PropertyDescriptorCollection props = TypeDescriptor.GetProperties(dataObject); 
            foreach (DictionaryEntry de in inputParameters) { 
                string propName = (de.Key == null ? String.Empty : de.Key.ToString());
                PropertyDescriptor property = props.Find(propName, /*ignoreCase*/true); 
                // NOTE: No longer throws when a property is not found or is read only.  This makes
                // Delete, Insert and Update operations more optimistic, allowing scenarios such as:
                // 1) Deletes and Updates after projecting data in the Selecting event.
                // 2) Deletes and Updates after selecting children of the data object type in the 
                //    Selecting event.
                if ((property != null) && (!property.IsReadOnly)) { 
                    try { 
                        object value = BuildObjectValue(de.Value, property.PropertyType, propName);
                        property.SetValue(dataObject, value); 
                    }
                    catch (Exception e) {
                        validationErrors[property.Name] = e;
                    } 
                }
            } 
 
            if (validationErrors.Any()) {
                return null; 
            }

            return dataObject;
        } 

        internal static object BuildObjectValue(object value, Type destinationType, string paramName) { 
            // NOTE: This method came from ObjectDataSource with no changes made. 
            // Only consider converting the type if the value is non-null and the types don't match
            if ((value != null) && (!destinationType.IsInstanceOfType(value))) { 
                Type innerDestinationType = destinationType;
                bool isNullable = false;
                if (destinationType.IsGenericType &&
                    (destinationType.GetGenericTypeDefinition() == typeof(Nullable<>))) { 
                    innerDestinationType = destinationType.GetGenericArguments()[0];
                    isNullable = true; 
                } 
                else {
                    if (destinationType.IsByRef) { 
                        innerDestinationType = destinationType.GetElementType();
                    }
                }
 
                // Try to convert from for example string to DateTime, so that
                // afterwards we can convert DateTime to Nullable 
 
                // If the value is a string, we attempt to use a TypeConverter to convert it
                value = ConvertType(value, innerDestinationType, paramName); 

                // Special-case the value when the destination is Nullable
                if (isNullable) {
                    Type paramValueType = value.GetType(); 
                    if (innerDestinationType != paramValueType) {
                        // Throw if for example, we are trying to convert from int to Nullable 
                        throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture, 
                            AtlasWeb.LinqDataSourceView_CannotConvertType, paramName, paramValueType.FullName,
                            String.Format(CultureInfo.InvariantCulture, "Nullable<{0}>", 
                            destinationType.GetGenericArguments()[0].FullName)));
                    }
                }
            } 
            return value;
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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DataSourceHelper.cs source code in C# .NET

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