Microsoft XRM Filter ConditionOperator to XML operators

XrmXmlConditionOperators.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Microsoft.Xrm.Sdk.Query;

public static class XmlConditionOperator
{
	// Credit for BCA https://stackoverflow.com/a/41618045/1238848
	public static Dictionary<string, string> GetAllPublicConstantValues(this Type type)
	{
		return type
			.GetFields(BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy)
			.Where(fi => fi.IsLiteral && !fi.IsInitOnly && fi.FieldType == typeof(string))
			.ToDictionary(x => x.Name, x => x.GetRawConstantValue().ToString());
	}
	public static Dictionary<TValue, TKey> FlipDictionary<TKey, TValue>(this Dictionary<TKey, TValue> dic)
		=> dic.ToDictionary(kp => kp.Value, kp => kp.Key);

	private readonly static Dictionary<string, string> _allConstantValues = typeof(XmlConditionOperator).GetAllPublicConstantValues();
	private readonly static Dictionary<string, string> _allConstantValuesFlip = _allConstantValues.FlipDictionary();
	public static ConditionOperator ToConditionOperator(string str)
	{
		var fieldName = _allConstantValuesFlip[str];
		return (ConditionOperator)Enum.Parse(typeof(ConditionOperator), fieldName);
	}
	public static string ToXmlOperator(ConditionOperator conditionOperator)
	{
		return _allConstantValues[conditionOperator.ToString()];
	}

	public const string Equal = "eq";
	public const string NotEqual = "neq";
	public const string GreaterThan = "gt"; //"ne"
	public const string LessThan = "lt";
	public const string GreaterEqual = "ge";
	public const string LessEqual = "le";
	public const string Like = "like";
	public const string NotLike = "not-like";
	public const string In = "in";
	public const string NotIn = "not-in";
	public const string Between = "between";
	public const string NotBetween = "not-between";
	public const string Null = "null";
	public const string NotNull = "not-null";
	public const string Yesterday = "yesterday";
	public const string Today = "today";
	public const string Tomorrow = "tomorrow";
	public const string Last7Days = "last-seven-days";
	public const string Next7Days = "next-seven-days";
	public const string LastWeek = "last-week";
	public const string ThisWeek = "this-week";
	public const string NextWeek = "next-week";
	public const string LastMonth = "last-month";
	public const string ThisMonth = "this-month";
	public const string NextMonth = "next-month";
	public const string On = "on";
	public const string OnOrBefore = "on-or-before";
	public const string OnOrAfter = "on-or-after";
	public const string LastYear = "last-year";
	public const string ThisYear = "this-year";
	public const string NextYear = "next-year";
	public const string LastXHours = "last-x-hours";
	public const string NextXHours = "next-x-hours";
	public const string LastXDays = "last-x-days";
	public const string NextXDays = "next-x-days";
	public const string LastXWeeks = "last-x-weeks";
	public const string NextXWeeks = "next-x-weeks";
	public const string LastXMonths = "last-x-months";
	public const string NextXMonths = "next-x-months";
	public const string LastXYears = "last-x-years";
	public const string NextXYears = "next-x-years";
	public const string EqualUserId = "eq-userid";
	public const string NotEqualUserId = "ne-userid";
	public const string EqualBusinessId = "eq-businessid";
	public const string NotEqualBusinessId = "ne-businessid";
	//public const string ChildOf = //;
	//public const string Mask = ;
	//public const string NotMask =
	//public const string MasksSelect = ;
	public const string Contains = "contains";
	public const string DoesNotContain = "does-not-contain";
	public const string EqualUserLanguage = "eq-userlanguage";
	//public const string NotOn = //
	public const string OlderThanXMonths = "olderthan-x-months";
	public const string BeginsWith = "begins-with";
	public const string DoesNotBeginWith = "not-begin-with";
	public const string EndsWith = "ends-with";
	public const string DoesNotEndWith = "not-end-with";
	public const string ThisFiscalYear = "this-fiscal-year";
	public const string ThisFiscalPeriod = "this-fiscal-period";
	public const string NextFiscalYear = "next-fiscal-year";
	public const string NextFiscalPeriod = "next-fiscal-period";
	public const string LastFiscalYear = "last-fiscal-year";
	public const string LastFiscalPeriod = "last-fiscal-period";
	public const string LastXFiscalYears = "last-x-fiscal-years";
	public const string LastXFiscalPeriods = "last-x-fiscal-periods";
	public const string NextXFiscalYears = "next-x-fiscal-years";
	public const string NextXFiscalPeriods = "next-x-fiscal-periods";
	public const string InFiscalYear = "in-fiscal-year";
	public const string InFiscalPeriod = "in-fiscal-period";
	public const string InFiscalPeriodAndYear = "in-fiscal-period-and-year";
	public const string InOrBeforeFiscalPeriodAndYear = "in-or-before-fiscal-period-and-year";
	public const string InOrAfterFiscalPeriodAndYear = "in-or-after-fiscal-period-and-year";
	public const string EqualUserTeams = "eq-userteams";
	public const string EqualUserOrUserTeams = "eq-useroruserteams";
	public const string Under = "under";
	public const string NotUnder = "not-under";
	public const string UnderOrEqual = "eq-or-under";
	public const string Above = "above";
	public const string AboveOrEqual = "eq-or-above";
	public const string EqualUserOrUserHierarchy = "eq-useroruserhierarchy";
	public const string EqualUserOrUserHierarchyAndTeams = "eq-useroruserhierarchyandteams";
	public const string OlderThanXYears = "olderthan-x-years";
	public const string OlderThanXWeeks = "olderthan-x-weeks";
	public const string OlderThanXDays = "olderthan-x-days";
	public const string OlderThanXHours = "olderthan-x-hours";
	public const string OlderThanXMinutes = "olderthan-x-minutes";
}