Files
UnrealEngine/Engine/Source/Programs/Shared/EpicGames.Core/JsonObject.cs
2025-05-18 13:04:45 +08:00

882 lines
28 KiB
C#

// Copyright Epic Games, Inc. All Rights Reserved.
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text.Json;
using System.Collections.Specialized;
using System.Collections;
using System.IO;
using System.Text;
using System.Text.Encodings.Web;
namespace EpicGames.Core
{
using SystemJsonObject = System.Text.Json.Nodes.JsonObject;
using SystemJsonNode = System.Text.Json.Nodes.JsonNode;
using SystemJsonValue = System.Text.Json.Nodes.JsonValue;
using SystemJsonArray = System.Text.Json.Nodes.JsonArray;
/// <summary>
/// Extension methods for OrderedDictionary to have functionality more similar to Dictionary.
/// </summary>
public static class OrderedDictionaryExtensions
{
/// <summary>
/// Tries to get a value associated with a key in the OrderedDictionary.
/// </summary>
/// <param name="dictionary"></param>
/// <param name="key"> The key to find a value for.</param>
/// <param name="value"> The value associated with the key. Is null if no key is found.</param>
/// <returns> Returns true if the associated value with the key exists and is found. Else returns false.</returns>
public static bool TryGetValue(this OrderedDictionary dictionary, object key, [NotNullWhen(true)] out object? value)
{
if (dictionary.Contains(key))
{
value = dictionary[key]!;
return true;
}
value = null;
return false;
}
private static object? DeepCopyHelper(object? original)
{
if (original is null)
{
return null;
}
if (original is OrderedDictionary dictionary)
{
OrderedDictionary copy = new OrderedDictionary(StringComparer.InvariantCultureIgnoreCase);
foreach (DictionaryEntry entry in dictionary)
{
copy.Add(entry.Key, DeepCopyHelper(entry.Value));
}
return copy;
}
if (original is Array array)
{
Array copy = Array.CreateInstance(array.GetType().GetElementType()!, array.Length);
for (int index = 0; index < array.Length; ++index)
{
copy.SetValue(DeepCopyHelper(array.GetValue(index)), index);
}
return copy;
}
// It's a value type or a string, it's safe to just copy it
return original;
}
/// <summary>
/// Creates a deep copy of all the elements in an OrderedDictionary.
/// </summary>
/// <param name="dictionary"></param>
/// <returns> An ordered dictionary with a deep copy of elements from dictionary.</returns>
public static OrderedDictionary CreateDeepCopy(this OrderedDictionary dictionary)
{
OrderedDictionary copy = new OrderedDictionary(StringComparer.InvariantCultureIgnoreCase);
foreach (DictionaryEntry entry in dictionary)
{
copy.Add(entry.Key, DeepCopyHelper(entry.Value));
}
return copy;
}
}
/// <summary>
/// Stores a JSON object in memory
/// </summary>
public class JsonObject
{
readonly OrderedDictionary _rawOrderedObject;
/// <summary>
/// Default constructor. Use this to create new JsonObject elements and use the AddOrSetFieldValue API to add values to this JsonObject.
/// </summary>
public JsonObject()
{
_rawOrderedObject = new OrderedDictionary(StringComparer.InvariantCultureIgnoreCase);
}
/// <summary>
/// Construct a JSON object from the OrderedDictionary obtained from reading a file on disk or parsing valid json text.
/// </summary>
/// <param name="inRawObject">Raw object parsed from disk</param>
private JsonObject(OrderedDictionary inRawObject)
{
_rawOrderedObject = inRawObject.CreateDeepCopy();
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="element"></param>
public JsonObject(JsonElement element)
{
_rawOrderedObject = new OrderedDictionary(StringComparer.InvariantCultureIgnoreCase);
foreach (JsonProperty property in element.EnumerateObject())
{
_rawOrderedObject[property.Name] = ParseElement(property.Value);
}
}
/// <summary>
/// Override of the Equals method to check for equality between 2 JsonObject instances.
/// </summary>
/// <param name="obj"></param>
/// <returns> Returns true if this object and obj are equal. Else returns false.</returns>
public override bool Equals(object? obj)
{
if (obj is null || GetType() != obj.GetType())
{
return false;
}
JsonObject jsonObject = (JsonObject) obj;
if (_rawOrderedObject.Count != jsonObject._rawOrderedObject.Count)
{
return false;
}
foreach (DictionaryEntry entry in _rawOrderedObject)
{
if (!jsonObject._rawOrderedObject.Contains(entry.Key))
{
return false;
}
if (!entry.Value!.Equals(jsonObject._rawOrderedObject[entry.Key!]))
{
return false;
}
}
return true;
}
/// <summary>
/// Returns the calculated hash code for a JsonObject instance.
/// </summary>
/// <returns> Returns the hash code for a JsonObject instance. </returns>
public override int GetHashCode()
{
return HashCode.Combine(_rawOrderedObject);
}
/// <summary>
/// Parse an individual element
/// </summary>
/// <param name="element"></param>
/// <returns></returns>
public static object? ParseElement(JsonElement element)
{
switch(element.ValueKind)
{
case JsonValueKind.Array:
return element.EnumerateArray().Select(x => ParseElement(x)).ToArray();
case JsonValueKind.Number:
return element.GetDouble();
case JsonValueKind.Object:
OrderedDictionary dictionary = new OrderedDictionary(StringComparer.InvariantCultureIgnoreCase);
foreach (JsonProperty property in element.EnumerateObject())
{
dictionary.Add(property.Name, ParseElement(property.Value));
}
return dictionary;
case JsonValueKind.String:
return element.GetString();
case JsonValueKind.False:
return false;
case JsonValueKind.True:
return true;
case JsonValueKind.Null:
return null;
default:
throw new NotImplementedException();
}
}
private static SystemJsonNode ToJsonNode(object? obj)
{
// All values in the JsonObject are either parsed from a string, read from a file or set/added with the API
// All values at this point must be supported and the correct types
switch (obj)
{
case OrderedDictionary objDictionary:
SystemJsonObject dictionaryJson= [];
foreach (object? key in objDictionary.Keys)
{
dictionaryJson.Add((string) key, ToJsonNode(objDictionary[key]));
}
return dictionaryJson;
case Array objArray:
SystemJsonArray tempJsonArray = [];
foreach (object? element in objArray)
{
tempJsonArray.Add(ToJsonNode(element));
}
return tempJsonArray;
default:
// We support null as per the json spec
return SystemJsonValue.Create(obj)!;
}
}
/// <summary>
/// Converts a JsonObject instance to a System.Text.Json.Nodes.JsonObject instance. Users can then use .NET facilities like Utf8JsonWriter to interact with this JsonObject.
/// </summary>
/// <returns> Returns the System.Text.Json.Nodes.JsonObject representation of this object.</returns>
public SystemJsonObject ToSystemJsonObject()
{
SystemJsonObject returnObject = [];
foreach (DictionaryEntry entry in _rawOrderedObject )
{
returnObject.Add((string) entry.Key, ToJsonNode(entry.Value));
}
return returnObject;
}
/// <summary>
/// Read a JSON file from disk and construct a JsonObject from it
/// </summary>
/// <param name="file">File to read from</param>
/// <returns>New JsonObject instance</returns>
public static JsonObject Read(FileReference file)
{
string text = FileReference.ReadAllText(file);
try
{
return Parse(text);
}
catch (JsonException)
{
throw;
}
catch (Exception ex)
{
throw new JsonException($"Unable to parse {file}: {ex.Message}", file.FullName, null, null, ex );
}
}
/// <summary>
/// Tries to read a JSON file from disk
/// </summary>
/// <param name="fileName">File to read from</param>
/// <param name="result">On success, receives the parsed object</param>
/// <returns>True if the file was read, false otherwise</returns>
public static bool TryRead(FileReference fileName, [NotNullWhen(true)] out JsonObject? result)
{
if (!FileReference.Exists(fileName))
{
result = null;
return false;
}
string text = FileReference.ReadAllText(fileName);
return TryParse(text, out result);
}
/// <summary>
/// Parse a JsonObject from the given raw text string
/// </summary>
/// <param name="text">The text to parse</param>
/// <returns>New JsonObject instance</returns>
public static JsonObject Parse(string text)
{
try
{
JsonDocument document = JsonDocument.Parse(text, new JsonDocumentOptions { AllowTrailingCommas = true });
return new JsonObject(document.RootElement);
}
catch (JsonException)
{
throw;
}
catch (Exception ex)
{
throw new JsonException($"Failed to parse json text '{text}'. {ex.Message}", ex);
}
}
/// <summary>
/// Try to parse a JsonObject from the given raw text string
/// </summary>
/// <param name="text">The text to parse</param>
/// <param name="result">On success, receives the new JsonObject</param>
/// <returns>True if the object was parsed</returns>
public static bool TryParse(string text, [NotNullWhen(true)] out JsonObject? result)
{
try
{
result = Parse(text);
return true;
}
catch (Exception)
{
result = null;
return false;
}
}
/// <summary>
/// List of key names in this object
/// </summary>
public IEnumerable<string> KeyNames => _rawOrderedObject.Keys.Cast<string>();
/// <summary>
/// Gets a string field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public string GetStringField(string fieldName)
{
string? stringValue;
if (!TryGetStringField(fieldName, out stringValue))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return stringValue;
}
/// <summary>
/// Tries to read a string field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetStringField(string fieldName, [NotNullWhen(true)] out string? result)
{
object? rawValue;
if (_rawOrderedObject.TryGetValue(fieldName, out rawValue) && (rawValue is string strValue))
{
result = strValue;
return true;
}
else
{
result = null;
return false;
}
}
/// <summary>
/// Gets a string array field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public string[] GetStringArrayField(string fieldName)
{
string[]? stringValues;
if (!TryGetStringArrayField(fieldName, out stringValues))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return stringValues;
}
/// <summary>
/// Tries to read a string array field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetStringArrayField(string fieldName, [NotNullWhen(true)] out string[]? result)
{
object? rawValue;
if (_rawOrderedObject.TryGetValue(fieldName, out rawValue) && (rawValue is IEnumerable<object> enumValue) && enumValue.All(x => x is string))
{
result = enumValue.Select(x => (string)x).ToArray();
return true;
}
else
{
result = null;
return false;
}
}
/// <summary>
/// Gets a boolean field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public bool GetBoolField(string fieldName)
{
bool boolValue;
if (!TryGetBoolField(fieldName, out boolValue))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return boolValue;
}
/// <summary>
/// Tries to read a bool field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetBoolField(string fieldName, out bool result)
{
object? rawValue;
if (_rawOrderedObject.TryGetValue(fieldName, out rawValue) && (rawValue is bool boolValue))
{
result = boolValue;
return true;
}
else
{
result = false;
return false;
}
}
/// <summary>
/// Gets an integer field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public int GetIntegerField(string fieldName)
{
int integerValue;
if (!TryGetIntegerField(fieldName, out integerValue))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return integerValue;
}
/// <summary>
/// Tries to read an integer field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetIntegerField(string fieldName, out int result)
{
object? rawValue;
if (!_rawOrderedObject.TryGetValue(fieldName, out rawValue) || !Int32.TryParse(rawValue?.ToString(), out result))
{
result = 0;
return false;
}
return true;
}
/// <summary>
/// Tries to read an unsigned integer field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetUnsignedIntegerField(string fieldName, out uint result)
{
object? rawValue;
if (!_rawOrderedObject.TryGetValue(fieldName, out rawValue) || !UInt32.TryParse(rawValue?.ToString(), out result))
{
result = 0;
return false;
}
return true;
}
/// <summary>
/// Gets a double field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public double GetDoubleField(string fieldName)
{
double doubleValue;
if (!TryGetDoubleField(fieldName, out doubleValue))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return doubleValue;
}
/// <summary>
/// Tries to read a double field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetDoubleField(string fieldName, out double result)
{
object? rawValue;
if (!_rawOrderedObject.TryGetValue(fieldName, out rawValue) || !Double.TryParse(rawValue?.ToString(), out result))
{
result = 0.0;
return false;
}
return true;
}
/// <summary>
/// Gets an enum field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public T GetEnumField<T>(string fieldName) where T : struct
{
T enumValue;
if (!TryGetEnumField(fieldName, out enumValue))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return enumValue;
}
/// <summary>
/// Tries to read an enum field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetEnumField<T>(string fieldName, out T result) where T : struct
{
string? stringValue;
if (!TryGetStringField(fieldName, out stringValue) || !Enum.TryParse<T>(stringValue, true, out result))
{
result = default;
return false;
}
return true;
}
/// <summary>
/// Tries to read an enum array field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetEnumArrayField<T>(string fieldName, [NotNullWhen(true)] out T[]? result) where T : struct
{
string[]? stringValues;
if (!TryGetStringArrayField(fieldName, out stringValues))
{
result = null;
return false;
}
T[] enumValues = new T[stringValues.Length];
for (int idx = 0; idx < stringValues.Length; idx++)
{
if (!Enum.TryParse<T>(stringValues[idx], true, out enumValues[idx]))
{
result = null;
return false;
}
}
result = enumValues;
return true;
}
/// <summary>
/// Gets an object field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public JsonObject GetObjectField(string fieldName)
{
JsonObject? result;
if (!TryGetObjectField(fieldName, out result))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return result;
}
/// <summary>
/// Tries to read an object field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetObjectField(string fieldName, [NotNullWhen(true)] out JsonObject? result)
{
object? rawValue;
if (_rawOrderedObject.TryGetValue(fieldName, out rawValue) && (rawValue is OrderedDictionary orderedDictValue))
{
result = new JsonObject(orderedDictValue);
return true;
}
else
{
result = null;
return false;
}
}
/// <summary>
/// Gets an object array field by the given name from the object, throwing an exception if it is not there or cannot be parsed.
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <returns>The field value</returns>
public JsonObject[] GetObjectArrayField(string fieldName)
{
JsonObject[]? result;
if (!TryGetObjectArrayField(fieldName, out result))
{
throw new JsonException($"Missing or invalid '{fieldName}' field");
}
return result;
}
/// <summary>
/// Tries to read an object array field by the given name from the object
/// </summary>
/// <param name="fieldName">Name of the field to get</param>
/// <param name="result">On success, receives the field value</param>
/// <returns>True if the field could be read, false otherwise</returns>
public bool TryGetObjectArrayField(string fieldName, [NotNullWhen(true)] out JsonObject[]? result)
{
object? rawValue;
if (_rawOrderedObject.TryGetValue(fieldName, out rawValue) && (rawValue is IEnumerable<object> enumValue) && enumValue.All(x => x is OrderedDictionary))
{
result = enumValue.Select(x => new JsonObject((OrderedDictionary)x)).ToArray();
return true;
}
else
{
result = null;
return false;
}
}
/// <summary>
/// Checks if the provided field exists in this Json object.
/// </summary>
/// <param name="fieldName">Name of the field to check if it is contained. </param>
/// <returns>True if the field exists in the JsonObject, false otherwise</returns>
public bool ContainsField(string fieldName)
{
return _rawOrderedObject.Contains(fieldName);
}
/// <summary>
/// Removes a field from the given json object.
/// </summary>
/// <param name="fieldName">Name of the field to remove </param>
public void RemoveField(string fieldName)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
if (ContainsField(fieldName))
{
_rawOrderedObject.Remove(fieldName);
}
}
/// <summary>
/// Sets the integer value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The integer value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, int value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
_rawOrderedObject[fieldName] = Convert.ToDouble(value);
}
/// <summary>
/// Sets the unsigned integer value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The unsigned integer value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, uint value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
_rawOrderedObject[fieldName] = Convert.ToDouble(value);
}
/// <summary>
/// Sets the double value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The double value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, double value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
_rawOrderedObject[fieldName] = value;
}
/// <summary>
/// Sets the bool value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The bool value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, bool value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
_rawOrderedObject[fieldName] = value;
}
/// <summary>
/// Sets the string value of a field if it exists. Otherwise, adds the field and value.
/// Note: If a null string is passed in as a value, it will be replaced with an empty string "" instead to ensure the field can still be added or set.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The string value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, string? value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
// We set null strings to empty strings to follow the behavior of EpicGames.Core.JsonWriter
value ??= "";
_rawOrderedObject[fieldName] = value;
}
/// <summary>
/// Sets the enum value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The enum value to add or set. </param>
public void AddOrSetFieldValue<T>(string fieldName, T value) where T : Enum
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
_rawOrderedObject[fieldName] = value.ToString();
}
/// <summary>
/// Sets the JsonObject value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The JsonObject value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, JsonObject? value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
_rawOrderedObject[fieldName] = value?._rawOrderedObject.CreateDeepCopy();
}
/// <summary>
/// Sets the string array value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The string array value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, string?[]? value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
if (value is null)
{
_rawOrderedObject[fieldName] = value;
return;
}
// Contents of the strings array should never be null and should be "" instead to match behavior EpicGames.Core.JsonWriter
string[] stringArray = value.Select(x => x ?? "").ToArray();
_rawOrderedObject[fieldName] = stringArray;
}
/// <summary>
/// Sets the JsonObject array value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The JsonObject array value to add or set. </param>
public void AddOrSetFieldValue(string fieldName, JsonObject[]? value)
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
if (value is null)
{
_rawOrderedObject[fieldName] = null;
return;
}
List<OrderedDictionary?> objList = [];
foreach (JsonObject? obj in value)
{
objList.Add(obj?._rawOrderedObject.CreateDeepCopy());
}
_rawOrderedObject[fieldName] = objList.ToArray();
}
/// <summary>
/// Sets the enum array value of a field if it exists. Otherwise, adds the field and value.
/// </summary>
/// <param name="fieldName"> The field name for the value to add or update.</param>
/// <param name="value"> The enum array value to add or set. </param>
public void AddOrSetFieldValue<T>(string fieldName, T[]? value) where T : Enum
{
if (String.IsNullOrEmpty(fieldName))
{
return;
}
if (value is null)
{
_rawOrderedObject[fieldName] = null;
return;
}
string[] stringArray = value.Select(x => x.ToString()!).ToArray();
_rawOrderedObject[fieldName] = stringArray;
}
/// <summary>
/// Converts this Json Object to a string representation. This follows formatting of UE .uplugin files with 4 spaces for tabs and indentation enabled.
/// IMPORTANT: If this JsonObject contains HTML, the returned string should NOT be used directly for HTML or a script. Read the note below.
/// </summary>
/// <returns>The formatted, prettified string representation of this Json Object.</returns>
public string ToJsonString()
{
SystemJsonObject jsonObjectToWrite = ToSystemJsonObject();
JsonWriterOptions options = new JsonWriterOptions();
options.Indented = true;
// IMPORTANT: Utf8JsonWriter blocks certain characters like +, &, <, >,` from being escaped in a global block list
// Best way around is to use the relaxed JavaScriptEncoder.UnsafeRelaxedJsonEscaping.
// However this can have security implications if this string is ever written to an HTML page or script
// https://learn.microsoft.com/en-us/dotnet/standard/serialization/system-text-json/character-encoding
options.Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping;
using MemoryStream jsonMemoryStream = new MemoryStream();
using (Utf8JsonWriter writer = new Utf8JsonWriter(jsonMemoryStream, options))
{
jsonObjectToWrite.WriteTo(writer);
writer.Flush();
}
// The Utf8JsonWriter doesn't format json the same as we want in UE, we massage the string to meet our standards
string jsonString = Encoding.UTF8.GetString(jsonMemoryStream.ToArray());
string[] lines = jsonString.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
StringBuilder jsonStringBuilder = new StringBuilder();
foreach (string line in lines)
{
// Utf8JsonWriter uses 2 spaces for indents, we replace them with tabs here
int numLeadingSpaces = line.TakeWhile(x => x == ' ').Count();
int numLeadingTabs = numLeadingSpaces / 2;
jsonStringBuilder.Append('\t', numLeadingTabs);
jsonStringBuilder.AppendLine(line.Substring(numLeadingSpaces));
}
return jsonStringBuilder.ToString();
}
}
}