JavaScriptSerializer.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ DotNET / DotNET / 8.0 / untmp / Orcas / RTM / ndp / fx / src / xsp / System / Web / Extensions / Script / Serialization / JavaScriptSerializer.cs / 1 / JavaScriptSerializer.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.Script.Serialization { 
    using System; 
    using System.Collections;
    using System.Collections.Generic; 
    using System.Diagnostics;
    using System.Diagnostics.CodeAnalysis;
    using System.Globalization;
    using System.Reflection; 
    using System.Security.Permissions;
    using System.Text; 
    using System.Web; 
    using System.Web.Resources;
 
    [
    AspNetHostingPermission(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal),
    AspNetHostingPermission(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)
    ] 
    public class JavaScriptSerializer {
        internal const string ServerTypeFieldName = "__type"; 
        internal const int DefaultRecursionLimit = 100; 
        internal const int DefaultMaxJsonLength = 2097152;
 
        internal static JavaScriptSerializer CreateInstance() {
            return CreateInstance(null);
        }
 
        internal static JavaScriptSerializer CreateInstance(JavaScriptTypeResolver resolver) {
#pragma warning disable 618 
            return new JavaScriptSerializer(resolver); 
#pragma warning restore 618
        } 

        internal static string SerializeInternal(object o) {
            JavaScriptSerializer serializer = JavaScriptSerializer.CreateInstance();
            return serializer.Serialize(o); 
        }
 
        internal static object Deserialize(JavaScriptSerializer serializer, string input, Type type, int depthLimit) { 
            if (input == null) {
                throw new ArgumentNullException("input"); 
            }
            if (input.Length > serializer.MaxJsonLength) {
                throw new ArgumentException(AtlasWeb.JSON_MaxJsonLengthExceeded, "input");
            } 

            object o = JavaScriptObjectDeserializer.BasicDeserialize(input, depthLimit, serializer); 
            return ObjectConverter.ConvertObjectToType(o, type, serializer); 
        }
 
        // INSTANCE fields/methods
        private JavaScriptTypeResolver _typeResolver;
        private int _recursionLimit;
        private int _maxJsonLength; 

        [Obsolete("The recommended alternative is System.Runtime.Serialization.DataContractJsonSerializer.")] 
        public JavaScriptSerializer() : this(null) { } 

        [Obsolete("The recommended alternative is System.Runtime.Serialization.DataContractJsonSerializer.")] 
        public JavaScriptSerializer(JavaScriptTypeResolver resolver) {
            _typeResolver = resolver;
            RecursionLimit = DefaultRecursionLimit;
            MaxJsonLength = DefaultMaxJsonLength; 
        }
 
        public int MaxJsonLength { 
            get {
                return _maxJsonLength; 
            }
            set {
                if (value < 1) {
                    throw new ArgumentOutOfRangeException(AtlasWeb.JSON_InvalidMaxJsonLength); 
                }
                _maxJsonLength = value; 
            } 
        }
 
        public int RecursionLimit {
            get {
                return _recursionLimit;
            } 
            set {
                if (value < 1) { 
                    throw new ArgumentOutOfRangeException(AtlasWeb.JSON_InvalidRecursionLimit); 
                }
                _recursionLimit = value; 
            }
        }

        internal JavaScriptTypeResolver TypeResolver { 
            get {
                return _typeResolver; 
            } 
        }
 
        private Dictionary _converters;
        private Dictionary Converters {
            get {
                if (_converters == null) { 
                    _converters = new Dictionary();
                } 
                return _converters; 
            }
        } 

        public void RegisterConverters(IEnumerable converters) {
            if (converters == null) {
                throw new ArgumentNullException("converters"); 
            }
 
            foreach (JavaScriptConverter converter in converters) { 
                IEnumerable supportedTypes = converter.SupportedTypes;
                if (supportedTypes != null) { 
                    foreach (Type supportedType in supportedTypes) {
                        Converters[supportedType] = converter;
                    }
                } 
            }
        } 
 
        private JavaScriptConverter GetConverter(Type t) {
            if (_converters != null) { 
                while (t != null) {
                    if (_converters.ContainsKey(t)) {
                        return _converters[t];
                    } 
                    t = t.BaseType;
                } 
            } 
            return null;
        } 

        internal bool ConverterExistsForType(Type t, out JavaScriptConverter converter) {
            converter = GetConverter(t);
            return converter != null; 
        }
 
        public object DeserializeObject(string input) { 
            return Deserialize(this, input, null /*type*/, RecursionLimit);
        } 

        [SuppressMessage("Microsoft.Design", "CA1004:GenericMethodsShouldProvideTypeParameter",
            Justification = "Generic parameter is preferable to forcing caller to downcast. " +
                "Has has been approved by API review board.")] 
        public T Deserialize(string input) {
            return (T)Deserialize(this, input, typeof(T), RecursionLimit); 
        } 

        [SuppressMessage("Microsoft.Design", "CA1004:GenericMethodsShouldProvideTypeParameter", 
            Justification = "Generic parameter is preferable to forcing caller to downcast. " +
                "Has has been approved by API review board.")]
        public T ConvertToType(object obj) {
            return (T)ObjectConverter.ConvertObjectToType(obj, typeof(T), this); 
        }
 
        public string Serialize(object obj) { 
            return Serialize(obj, SerializationFormat.JSON);
        } 

        private string Serialize(object obj, SerializationFormat serializationFormat) {
            StringBuilder sb = new StringBuilder();
            Serialize(obj, sb, serializationFormat); 
            return sb.ToString();
        } 
 
        public void Serialize(object obj, StringBuilder output) {
            Serialize(obj, output, SerializationFormat.JSON); 
        }

        internal void Serialize(object obj, StringBuilder output, SerializationFormat serializationFormat) {
            SerializeValue(obj, output, 0, null, serializationFormat); 
            // DevDiv Bugs 96574: Max JSON length does not apply when serializing to Javascript for ScriptDescriptors
            if (serializationFormat == SerializationFormat.JSON && output.Length > MaxJsonLength) { 
                throw new InvalidOperationException(AtlasWeb.JSON_MaxJsonLengthExceeded); 
            }
        } 

        private static void SerializeBoolean(bool o, StringBuilder sb) {
            if (o) {
                sb.Append("true"); 
            }
            else { 
                sb.Append("false"); 
            }
        } 

        private static void SerializeUri(Uri uri, StringBuilder sb) {
            sb.Append("\"").Append(uri.GetComponents(UriComponents.SerializationInfoString, UriFormat.UriEscaped)).Append("\"");
        } 

        private static void SerializeGuid(Guid guid, StringBuilder sb) { 
            sb.Append("\"").Append(guid.ToString()).Append("\""); 
        }
 
        internal static readonly long DatetimeMinTimeTicks = (new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).Ticks;
        private static void SerializeDateTime(DateTime datetime, StringBuilder sb, SerializationFormat serializationFormat) {
            Debug.Assert(serializationFormat == SerializationFormat.JSON || serializationFormat == SerializationFormat.JavaScript);
            if (serializationFormat == SerializationFormat.JSON) { 
                // DevDiv 41127: Never confuse atlas serialized strings with dates
                // Serialized date: "\/Date(123)\/" 
                sb.Append(@"""\/Date("); 
                sb.Append((datetime.ToUniversalTime().Ticks - DatetimeMinTimeTicks) / 10000);
                sb.Append(@")\/"""); 
            }
            else {
                // DevDiv 96574: Need to be able to serialize to javascript dates for script descriptors
                // new Date(ticks) 
                sb.Append("new Date(");
                sb.Append((datetime.ToUniversalTime().Ticks - DatetimeMinTimeTicks) / 10000); 
                sb.Append(@")"); 
            }
        } 

        // Serialize custom object graph
        private void SerializeCustomObject(object o, StringBuilder sb, int depth, Hashtable objectsInUse, SerializationFormat serializationFormat) {
            bool first = true; 
            Type type = o.GetType();
            sb.Append('{'); 
 
            // Serialize the object type if we have a type resolver
            if (TypeResolver != null) { 

                // Only do this if the context is actually aware of this type
                string typeString = TypeResolver.ResolveTypeId(type);
                if (typeString != null) { 
                    SerializeString(ServerTypeFieldName, sb);
                    sb.Append(':'); 
                    SerializeValue(typeString, sb, depth, objectsInUse, serializationFormat); 
                    first = false;
                } 
            }

            FieldInfo[] fields = type.GetFields(BindingFlags.Public | BindingFlags.Instance);
            foreach (FieldInfo fieldInfo in fields) { 

                // Ignore all fields marked as [ScriptIgnore] 
                if (fieldInfo.IsDefined(typeof(ScriptIgnoreAttribute), true /*inherits*/)) continue; 

                if (!first) sb.Append(','); 
                SerializeString(fieldInfo.Name, sb);
                sb.Append(':');
                SerializeValue(fieldInfo.GetValue(o), sb, depth, objectsInUse, serializationFormat);
                first = false; 
            }
 
            PropertyInfo[] props = type.GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.GetProperty); 
            foreach (PropertyInfo propInfo in props) {
 
                // Ignore all properties marked as [ScriptIgnore]
                if (propInfo.IsDefined(typeof(ScriptIgnoreAttribute), true /*inherits*/))
                    continue;
 
                MethodInfo getMethodInfo = propInfo.GetGetMethod();
 
                // Skip property if it has no get 
                if (getMethodInfo == null) {
                    continue; 
                }

                // Ignore indexed properties
                if (getMethodInfo.GetParameters().Length > 0) continue; 

                if (!first) sb.Append(','); 
                SerializeString(propInfo.Name, sb); 
                sb.Append(':');
                SerializeValue(getMethodInfo.Invoke(o, null), sb, depth, objectsInUse, serializationFormat); 
                first = false;
            }

            sb.Append('}'); 
        }
 
        private void SerializeDictionary(IDictionary o, StringBuilder sb, int depth, Hashtable objectsInUse, SerializationFormat serializationFormat) { 
            sb.Append('{');
            bool isFirstElement = true; 
            bool isTypeEntrySet = false;

            //make sure __type field is the first to be serialized if it exists
            if (o.Contains(ServerTypeFieldName)) { 
                isFirstElement = false;
                isTypeEntrySet = true; 
                SerializeDictionaryKeyValue(ServerTypeFieldName, o[ServerTypeFieldName], sb, depth, objectsInUse, serializationFormat); 
            }
 
            foreach (DictionaryEntry entry in (IDictionary)o) {

                string key = entry.Key as string;
                if (key == null) { 
                   throw new ArgumentException(String.Format(CultureInfo.InvariantCulture, AtlasWeb.JSON_DictionaryTypeNotSupported, o.GetType().FullName));
                } 
                if (isTypeEntrySet && String.Equals(key, ServerTypeFieldName, StringComparison.Ordinal)) { 
                    // The dictionay only contains max one entry for __type key, and it has been iterated
                    // through, so don't need to check for is anymore. 
                    isTypeEntrySet = false;
                    continue;
                }
                if (!isFirstElement) { 
                    sb.Append(',');
                } 
                SerializeDictionaryKeyValue(key, entry.Value, sb, depth, objectsInUse, serializationFormat); 
                isFirstElement = false;
            } 
            sb.Append('}');
        }

        private void SerializeDictionaryKeyValue(string key, object value, StringBuilder sb, int depth, Hashtable objectsInUse, SerializationFormat serializationFormat) { 

            SerializeString(key, sb); 
            sb.Append(':'); 
            SerializeValue(value, sb, depth, objectsInUse, serializationFormat);
        } 

        private void SerializeEnumerable(IEnumerable enumerable, StringBuilder sb, int depth, Hashtable objectsInUse, SerializationFormat serializationFormat) {
            sb.Append('[');
            bool isFirstElement = true; 
            foreach (object o in enumerable) {
                if (!isFirstElement) { 
                    sb.Append(','); 
                }
 
                SerializeValue(o, sb, depth, objectsInUse, serializationFormat);
                isFirstElement = false;
            }
            sb.Append(']'); 
        }
 
        private static void SerializeString(string input, StringBuilder sb) { 
            sb.Append('"');
            sb.Append(JavaScriptString.QuoteString(input)); 
            sb.Append('"');
        }

        private void SerializeValue(object o, StringBuilder sb, int depth, Hashtable objectsInUse, SerializationFormat serializationFormat) { 
            if (++depth > _recursionLimit) {
                throw new ArgumentException(AtlasWeb.JSON_DepthLimitExceeded); 
            } 

            // Check whether a custom converter is available for this type. 
            JavaScriptConverter converter = null;
            if (o != null && ConverterExistsForType(o.GetType(), out converter)) {
                IDictionary dict = converter.Serialize(o, this);
 
                if (TypeResolver != null) {
                    string typeString = TypeResolver.ResolveTypeId(o.GetType()); 
                    if (typeString != null) { 
                        dict[ServerTypeFieldName] = typeString;
                    } 
                }

                sb.Append(Serialize(dict, serializationFormat));
                return; 
            }
 
            SerializeValueInternal(o, sb, depth, objectsInUse, serializationFormat); 
        }
 
        // We use this for our cycle detection for the case where objects override equals/gethashcode
        private class ReferenceComparer : IEqualityComparer {
            bool IEqualityComparer.Equals(object x, object y) {
                return x == y; 
            }
 
            int IEqualityComparer.GetHashCode(object obj) { 
                return System.Runtime.CompilerServices.RuntimeHelpers.GetHashCode(obj);
            } 
        }

        private void SerializeValueInternal(object o, StringBuilder sb, int depth, Hashtable objectsInUse, SerializationFormat serializationFormat) {
            // 'null' is a special JavaScript token 
            if (o == null || DBNull.Value.Equals(o)) {
                sb.Append("null"); 
                return; 
            }
 
            // Strings and chars are represented as quoted (single or double) in Javascript.
            string os = o as String;
            if (os != null) {
                SerializeString(os, sb); 
                return;
            } 
 
            if (o is Char) {
                // Special case the null char as we don't want it to turn into a null string 
                if ((char)o == '\0') {
                    sb.Append("null");
                    return;
                } 
                SerializeString(o.ToString(), sb);
                return; 
            } 

            // Bools are represented as 'true' and 'false' (no quotes) in Javascript. 
            if (o is bool) {
                SerializeBoolean((bool)o, sb);
                return;
            } 

            if (o is DateTime) { 
                SerializeDateTime((DateTime)o, sb, serializationFormat); 
                return;
            } 

            if (o is Guid) {
                SerializeGuid((Guid)o, sb);
                return; 
            }
 
            Uri uri = o as Uri; 
            if (uri != null) {
                SerializeUri(uri, sb); 
                return;
            }

            // Have to special case floats to get full precision 
            if (o is double) {
                sb.Append(((double)o).ToString("r", CultureInfo.InvariantCulture)); 
                return; 
            }
 
            if (o is float) {
                sb.Append(((float)o).ToString("r", CultureInfo.InvariantCulture));
                return;
            } 

            // Deal with any server type that can be represented as a number in JavaScript 
            if (o.GetType().IsPrimitive || o is Decimal) { 
                IConvertible convertible = o as IConvertible;
                if (convertible != null) { 
                    sb.Append(convertible.ToString(CultureInfo.InvariantCulture));
                }
                else {
                    // In theory, all primitive types implement IConvertible 
                    Debug.Assert(false);
                    sb.Append(o.ToString()); 
                } 
                return;
            } 

            // Serialize enums as their integer value
            Type type = o.GetType();
            if (type.IsEnum) { 
                sb.Append((int)o);
                return; 
            } 

            try { 
                // The following logic performs circular reference detection
                if (objectsInUse == null) {
                    // Create the table on demand
                    objectsInUse = new Hashtable(new ReferenceComparer()); 
                }
                else if (objectsInUse.ContainsKey(o)) { 
                    // If the object is already there, we have a circular reference! 
                    throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, AtlasWeb.JSON_CircularReference, type.FullName));
                } 
                // Add the object to the objectsInUse
                objectsInUse.Add(o, null);

                // Dictionaries are represented as Javascript objects.  e.g. { name1: val1, name2: val2 } 
                IDictionary od = o as IDictionary;
                if (od != null) { 
                    SerializeDictionary(od, sb, depth, objectsInUse, serializationFormat); 
                    return;
                } 

                // Enumerations are represented as Javascript arrays.  e.g. [ val1, val2 ]
                IEnumerable oenum = o as IEnumerable;
                if (oenum != null) { 
                    SerializeEnumerable(oenum, sb, depth, objectsInUse, serializationFormat);
                    return; 
                } 

                // Serialize all public fields and properties. 
                SerializeCustomObject(o, sb, depth, objectsInUse, serializationFormat);
            }
            finally {
                // Remove the object from the circular reference detection table 
                if (objectsInUse != null) {
                    objectsInUse.Remove(o); 
                } 
            }
        } 

        internal enum SerializationFormat {
            JSON,
            JavaScript 
        }
    } 
} 

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

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