Modular mapping configuration (#162)

* Modular configuration for property mappings

* Update Readme, unit tests and sample

Co-authored-by: Steven Decoodt <steven.decoodt@vinci-energies.net>

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,38 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Desktop (please complete the following information):**
+ - OS: [e.g. iOS]
+ - Browser [e.g. chrome, safari]
+ - Version [e.g. 22]
+
+**Smartphone (please complete the following information):**
+ - Device: [e.g. iPhone6]
+ - OS: [e.g. iOS8.1]
+ - Browser [e.g. stock browser, safari]
+ - Version [e.g. 22]
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Feature Request
+    url: https://github.com/biarity/sieve/discussions/new
+    about: Share your ideas on how to make Sieve better.

.github/workflows/ci.yml

@@ -17,12 +17,10 @@
 name: ci
 
 on:
-  push:
-    branches:
-      - master
   pull_request:
     branches:
       - master
+      - 'releases/*'
 
 jobs:
   ubuntu-latest:

.github/workflows/ci_publish.yml

@@ -0,0 +1,35 @@
+# ------------------------------------------------------------------------------
+# <auto-generated>
+#
+#     This code was generated.
+#
+#     - To turn off auto-generation set:
+#
+#         [GitHubActions (AutoGenerate = false)]
+#
+#     - To trigger manual generation invoke:
+#
+#         nuke --generate-configuration GitHubActions_ci_publish --host GitHubActions
+#
+# </auto-generated>
+# ------------------------------------------------------------------------------
+
+name: ci_publish
+
+on:
+  push:
+    branches:
+      - 'releases/*'
+    tags:
+      - 'v*'
+
+jobs:
+  ubuntu-latest:
+    name: ubuntu-latest
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Run './build.cmd CiPublish'
+        run: ./build.cmd CiPublish
+        env:
+          NUGET_API_KEY: ${{ secrets.NUGET_API_KEY }}

.nuke/build.schema.json

@@ -43,6 +43,9 @@
           "type": "boolean",
           "description": "Disables displaying the NUKE logo"
         },
+        "NUGET_API_KEY": {
+          "type": "string"
+        },
         "Plan": {
           "type": "boolean",
           "description": "Shows the execution plan (HTML)"
@@ -65,9 +68,11 @@
             "type": "string",
             "enum": [
               "Ci",
+              "CiPublish",
               "Clean",
               "Compile",
               "Package",
+              "Publish",
               "Restore",
               "Test"
             ]
@@ -84,9 +89,11 @@
             "type": "string",
             "enum": [
               "Ci",
+              "CiPublish",
               "Clean",
               "Compile",
               "Package",
+              "Publish",
               "Restore",
               "Test"
             ]

GitVersion.yml

@@ -0,0 +1,3 @@
+branches:
+  release:
+    mode: ContinuousDeployment

README.md

@@ -2,7 +2,8 @@
 ⚗️ Sieve is a simple, clean, and extensible framework for .NET Core that **adds sorting, filtering, and pagination functionality out of the box**. 
 Most common use case would be for serving ASP.NET Core GET queries.
 
-[![NuGet Release](https://img.shields.io/nuget/v/Sieve.svg?style=flat-square)](https://www.nuget.org/packages/Sieve)
+[![NuGet Release](https://img.shields.io/nuget/v/Sieve?style=for-the-badge)](https://www.nuget.org/packages/Sieve)
+[![NuGet Pre-Release](https://img.shields.io/nuget/vpre/Sieve?style=for-the-badge)](https://www.nuget.org/packages/Sieve)
 
 [Get Sieve on nuget](https://www.nuget.org/packages/Sieve/)
 
@@ -74,7 +75,7 @@ Where `SieveCustomSortMethodsOfPosts` for example is:
 ```C#
 public class SieveCustomSortMethods : ISieveCustomSortMethods
 {
-    public IQueryable<Post> Popularity(IQueryable<Post> source, bool useThenBy, bool desc) // The method is given an indicator of weather to use ThenBy(), and if the query is descending 
+    public IQueryable<Post> Popularity(IQueryable<Post> source, bool useThenBy, bool desc) // The method is given an indicator of whether to use ThenBy(), and if the query is descending 
     {
         var result = useThenBy ?
             ((IOrderedQueryable<Post>)source).ThenBy(p => p.LikeCount) : // ThenBy only works on IOrderedQueryable<TEntity>
@@ -127,7 +128,8 @@ Then you can add the configuration:
         "CaseSensitive": "boolean: should property names be case-sensitive? Defaults to false",
         "DefaultPageSize": "int number: optional number to fallback to when no page argument is given. Set <=0 to disable paging if no pageSize is specified (default).",
         "MaxPageSize": "int number: maximum allowed page size. Set <=0 to make infinite (default)",
-        "ThrowExceptions": "boolean: should Sieve throw exceptions instead of silently failing? Defaults to false"
+        "ThrowExceptions": "boolean: should Sieve throw exceptions instead of silently failing? Defaults to false",
+        "IgnoreNullsOnNotEqual": "boolean: ignore null values when filtering using is not equal operator? Default to true"
     }
 }
 ```
@@ -157,7 +159,10 @@ More formally:
 * `pageSize` is the number of items returned per page 
 
 Notes:
-* You can use backslashes to escape commas and pipes within value fields
+* You can use backslashes to escape special characters and sequences:
+    * commas: `Title@=some\,title` makes a match with "some,title"
+    * pipes: `Title@=some\|title` makes a match with "some|title"
+    * null values: `Title@=\null` will search for items with title equal to "null" (not a missing value, but "null"-string literally)
 * You can have spaces anywhere except *within* `{Name}` or `{Operator}` fields
 * If you need to look at the data before applying pagination (eg. get total count), use the optional paramters on `Apply` to defer pagination (an [example](https://github.com/Biarity/Sieve/issues/34))
 * Here's a [good example on how to work with enumerables](https://github.com/Biarity/Sieve/issues/2)
@@ -258,13 +263,78 @@ public class ApplicationSieveProcessor : SieveProcessor
 }
 ```
 
+
+
 Now you should inject the new class instead:
 ```C#
 services.AddScoped<ISieveProcessor, ApplicationSieveProcessor>();
 ```
-
 Find More on Sieve's Fluent API [here](https://github.com/Biarity/Sieve/issues/4#issuecomment-364629048).
 
+### Modular Fluent API configuration
+Adding all fluent mappings directly in the processor can become unwieldy on larger projects.
+It can also clash with vertical architectures.
+To enable functional grouping of mappings the `ISieveConfiguration` interface was created together with extensions to the default mapper.
+```C#
+public class SieveConfigurationForPost : ISieveConfiguration
+{
+    protected override SievePropertyMapper Configure(SievePropertyMapper mapper)
+    {
+        mapper.Property<Post>(p => p.Title)
+            .CanFilter()
+            .HasName("a_different_query_name_here");
+
+        mapper.Property<Post>(p => p.CommentCount)
+            .CanSort();
+
+        mapper.Property<Post>(p => p.DateCreated)
+            .CanSort()
+            .CanFilter()
+            .HasName("created_on");
+
+        return mapper;
+    }
+}
+```
+With the processor simplified to:
+```C#
+public class ApplicationSieveProcessor : SieveProcessor
+{
+    public ApplicationSieveProcessor(
+        IOptions<SieveOptions> options, 
+        ISieveCustomSortMethods customSortMethods, 
+        ISieveCustomFilterMethods customFilterMethods) 
+        : base(options, customSortMethods, customFilterMethods)
+    {
+    }
+
+    protected override SievePropertyMapper MapProperties(SievePropertyMapper mapper)
+    {
+        return mapper
+            .ApplyConfiguration<SieveConfigurationForPost>()
+            .ApplyConfiguration<SieveConfigurationForComment>();       
+    }
+}
+```
+There is also the option to scan and add all configurations for a given assembly
+```C#
+public class ApplicationSieveProcessor : SieveProcessor
+{
+    public ApplicationSieveProcessor(
+        IOptions<SieveOptions> options, 
+        ISieveCustomSortMethods customSortMethods, 
+        ISieveCustomFilterMethods customFilterMethods) 
+        : base(options, customSortMethods, customFilterMethods)
+    {
+    }
+
+    protected override SievePropertyMapper MapProperties(SievePropertyMapper mapper)
+    {
+        return mapper.ApplyConfigurationForAssembly(typeof(ApplicationSieveProcessor).Assembly);            
+    }
+}
+```
+
 ## Upgrading to v2.2.0
 
 2.2.0 introduced OR logic for filter values. This means your custom filters will need to accept multiple values rather than just the one.

Sieve.Sample/Entities/SieveConfigurationForPost.cs

@@ -0,0 +1,15 @@
+using Sieve.Services;
+
+namespace Sieve.Sample.Entities
+{
+    public class SieveConfigurationForPost : ISieveConfiguration
+    {
+        public void Configure(SievePropertyMapper mapper)
+        {
+            mapper.Property<Post>(p => p.Title)
+                .CanSort()
+                .CanFilter()
+                .HasName("CustomTitleName");
+        }
+    }
+}

Sieve.Sample/Services/ApplicationSieveProcessor.cs

@@ -13,11 +13,18 @@ namespace Sieve.Sample.Services
 
         protected override SievePropertyMapper MapProperties(SievePropertyMapper mapper)
         {
+            // Option 1: Map all properties centrally
             mapper.Property<Post>(p => p.Title)
                 .CanSort()
                 .CanFilter()
                 .HasName("CustomTitleName");
 
+            // Option 2: Manually apply functionally grouped mapping configurations
+            //mapper.ApplyConfiguration<SieveConfigurationForPost>();
+            
+            // Option 3: Scan and apply all configurations
+            //mapper.ApplyConfigurationsFromAssembly(typeof(ApplicationSieveProcessor).Assembly);
+
             return mapper;
         }
     }

Sieve.Sample/appsettings.Development.json

@@ -1,6 +1,5 @@
 {
   "Logging": {
-    "IncludeScopes": false,
     "LogLevel": {
       "Default": "Debug",
       "System": "Information",

Sieve.Sample/appsettings.json

@@ -4,10 +4,10 @@
   },
   "Sieve": {
     "CaseSensitive": false,
-    "DefaultPageSize": 10
+    "DefaultPageSize": 10,
+    "IgnoreNullsOnNotEqual": true
   },
   "Logging": {
-    "IncludeScopes": false,
     "Debug": {
       "LogLevel": {
         "Default": "Warning"

Sieve/Models/FilterTerm.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
 
@@ -6,45 +7,49 @@ namespace Sieve.Models
 {
     public class FilterTerm : IFilterTerm, IEquatable<FilterTerm>
     {
-        public FilterTerm() { }
+        private const string EscapedPipePattern = @"(?<!($|[^\\]|^)(\\\\)*?\\)\|";
+        private const string OperatorsRegEx = @"(!@=\*|!_=\*|!=\*|!@=|!_=|==\*|@=\*|_=\*|==|!=|>=|<=|>|<|@=|_=)";
+        private const string EscapeNegPatternForOper = @"(?<!\\)" + OperatorsRegEx;
+        private const string EscapePosPatternForOper = @"(?<=\\)" + OperatorsRegEx;
 
-        private const string EscapedPipePattern = @"(?<!($|[^\\])(\\\\)*?\\)\|";
-
-        private static readonly string[] Operators = new string[] {
-                    "!@=*",
-                    "!_=*",
-                    "!=*",
-                    "!@=",
-                    "!_=",
-                    "==*",
-                    "@=*",
-                    "_=*",
-                    "==",
-                    "!=",
-                    ">=",
-                    "<=",
-                    ">",
-                    "<",
-                    "@=",
-                    "_="
+        private static readonly HashSet<string> _escapedSequences = new HashSet<string>
+        {
+            @"\|",
+            @"\\"
         };
 
         public string Filter
         {
             set
             {
-                var filterSplits = value.Split(Operators, StringSplitOptions.RemoveEmptyEntries)
-                    .Select(t => t.Trim()).ToArray();
+                var filterSplits = Regex.Split(value,EscapeNegPatternForOper).Select(t => t.Trim()).ToArray();
+                
                 Names = Regex.Split(filterSplits[0], EscapedPipePattern).Select(t => t.Trim()).ToArray();
-                Values = filterSplits.Length > 1 ? Regex.Split(filterSplits[1], EscapedPipePattern).Select(t => t.Trim()).ToArray() : null;
-                Operator = Array.Find(Operators, o => value.Contains(o)) ?? "==";
+
+                if (filterSplits.Length > 2)
+                {
+                    foreach (var match in Regex.Matches(filterSplits[2],EscapePosPatternForOper))
+                    {
+                        var matchStr = match.ToString();
+                        filterSplits[2] = filterSplits[2].Replace('\\' + matchStr, matchStr);
+                    }
+
+                    Values = Regex.Split(filterSplits[2], EscapedPipePattern)
+                        .Select(UnEscape)
+                        .ToArray();
+                }
+ 
+                Operator = Regex.Match(value,EscapeNegPatternForOper).Value;
                 OperatorParsed = GetOperatorParsed(Operator);
                 OperatorIsCaseInsensitive = Operator.EndsWith("*");
                 OperatorIsNegated = OperatorParsed != FilterOperator.NotEquals && Operator.StartsWith("!");
             }
-
         }
 
+        private string UnEscape(string escapedTerm)
+            => _escapedSequences.Aggregate(escapedTerm,
+                (current, sequence) => Regex.Replace(current, $@"(\\)({sequence})", "$2"));
+
         public string[] Names { get; private set; }
 
         public FilterOperator OperatorParsed { get; private set; }
@@ -90,6 +95,5 @@ namespace Sieve.Models
                 && Values.SequenceEqual(other.Values)
                 && Operator == other.Operator;
         }
-
     }
 }

Sieve/Models/SieveModel.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;

Sieve/Models/SieveOptions.cs

@@ -9,5 +9,7 @@
         public int MaxPageSize { get; set; } = 0;
 
         public bool ThrowExceptions { get; set; } = false;
+
+        public bool IgnoreNullsOnNotEqual { get; set; } = true;
     }
 }

Sieve/Services/ISieveConfiguration.cs

@@ -0,0 +1,70 @@
+#nullable enable
+using System;
+using System.Linq;
+using System.Reflection;
+
+namespace Sieve.Services
+{
+    /// <summary>
+    /// Use this interface to create SieveConfiguration (just like EntityTypeConfigurations are defined for EF)
+    /// </summary>
+    public interface ISieveConfiguration
+    {
+        /// <summary>
+        ///  Configures sieve property mappings.
+        /// </summary>
+        /// <param name="mapper"> The mapper used to configure the sieve properties on. </param>
+        void Configure(SievePropertyMapper mapper);
+    }
+
+    /// <summary>
+    /// Configuration extensions to the <see cref="SievePropertyMapper" />
+    /// </summary>
+    public static class SieveConfigurationExtensions
+    {
+        /// <summary>
+        ///     Applies configuration that is defined in an <see cref="ISieveConfiguration" /> instance.
+        /// </summary>
+        /// <param name="mapper"> The mapper to apply the configuration on. </param>
+        /// <typeparam name="T">The configuration to be applied. </typeparam>
+        /// <returns>
+        ///     The same <see cref="SievePropertyMapper" /> instance so that additional configuration calls can be chained.
+        /// </returns>
+        public static SievePropertyMapper ApplyConfiguration<T>(this SievePropertyMapper mapper) where T : ISieveConfiguration, new()
+        {
+            var configuration = new T();
+            configuration.Configure(mapper);
+            return mapper;
+        }
+
+        /// <summary>
+        ///     Applies configuration from all <see cref="ISieveConfiguration" />
+        ///     instances that are defined in provided assembly.
+        /// </summary>
+        /// <param name="mapper"> The mapper to apply the configuration on. </param>
+        /// <param name="assembly"> The assembly to scan. </param>
+        /// <returns>
+        ///     The same <see cref="SievePropertyMapper" /> instance so that additional configuration calls can be chained.
+        /// </returns>
+        public static SievePropertyMapper ApplyConfigurationsFromAssembly(this SievePropertyMapper mapper, Assembly assembly)
+        {
+            foreach (var type in assembly.GetTypes().Where(t => !t.IsAbstract && !t.IsGenericTypeDefinition))
+            {
+                // Only accept types that contain a parameterless constructor, are not abstract.
+                var noArgConstructor = type.GetConstructor(Type.EmptyTypes);
+                if (noArgConstructor is null)
+                {
+                    continue;
+                }
+
+                if (type.GetInterfaces().Any(t => t == typeof(ISieveConfiguration)))
+                {
+                    var configuration = (ISieveConfiguration)noArgConstructor.Invoke(new object?[] { });
+                    configuration.Configure(mapper);
+                }
+            }
+
+            return mapper;
+        }
+    }
+}

Sieve/Services/SieveProcessor.cs

@@ -68,7 +68,7 @@ namespace Sieve.Services
         where TSortTerm : ISortTerm, new()
     {
         private const string NullFilterValue = "null";
-        private readonly IOptions<SieveOptions> _options;
+        private const char EscapeChar = '\\';
         private readonly ISieveCustomSortMethods _customSortMethods;
         private readonly ISieveCustomFilterMethods _customFilterMethods;
         private readonly SievePropertyMapper _mapper = new SievePropertyMapper();
@@ -78,7 +78,7 @@ namespace Sieve.Services
             ISieveCustomFilterMethods customFilterMethods)
         {
             _mapper = MapProperties(_mapper);
-            _options = options;
+            Options = options;
             _customSortMethods = customSortMethods;
             _customFilterMethods = customFilterMethods;
         }
@@ -87,7 +87,7 @@ namespace Sieve.Services
             ISieveCustomSortMethods customSortMethods)
         {
             _mapper = MapProperties(_mapper);
-            _options = options;
+            Options = options;
             _customSortMethods = customSortMethods;
         }
 
@@ -95,16 +95,18 @@ namespace Sieve.Services
             ISieveCustomFilterMethods customFilterMethods)
         {
             _mapper = MapProperties(_mapper);
-            _options = options;
+            Options = options;
             _customFilterMethods = customFilterMethods;
         }
 
         public SieveProcessor(IOptions<SieveOptions> options)
         {
             _mapper = MapProperties(_mapper);
-            _options = options;
+            Options = options;
         }
 
+        protected IOptions<SieveOptions> Options { get; }
+
         /// <summary>
         /// Apply filtering, sorting, and pagination parameters found in `model` to `source`
         /// </summary>
@@ -148,7 +150,7 @@ namespace Sieve.Services
             }
             catch (Exception ex)
             {
-                if (!_options.Value.ThrowExceptions)
+                if (!Options.Value.ThrowExceptions)
                 {
                     return result;
                 }
@@ -162,7 +164,7 @@ namespace Sieve.Services
             }
         }
 
-        private IQueryable<TEntity> ApplyFiltering<TEntity>(TSieveModel model, IQueryable<TEntity> result,
+        protected virtual IQueryable<TEntity> ApplyFiltering<TEntity>(TSieveModel model, IQueryable<TEntity> result,
             object[] dataForCustomMethods = null)
         {
             if (model?.GetFiltersParsed() == null)
@@ -198,7 +200,7 @@ namespace Sieve.Services
                                 ? Expression.Constant(null, property.PropertyType)
                                 : ConvertStringValueToConstantExpression(filterTermValue, property, converter);
 
-                            if (filterTerm.OperatorIsCaseInsensitive)
+                            if (filterTerm.OperatorIsCaseInsensitive && !isFilterTermValueNull)
                             {
                                 propertyValue = Expression.Call(propertyValue,
                                     typeof(string).GetMethods()
@@ -216,11 +218,14 @@ namespace Sieve.Services
                                 expression = Expression.Not(expression);
                             }
 
+                            if (expression.NodeType != ExpressionType.NotEqual || Options.Value.IgnoreNullsOnNotEqual)
+                            {
                                 var filterValueNullCheck = GetFilterValueNullCheck(parameter, fullPropertyName, isFilterTermValueNull);
                                 if (filterValueNullCheck != null)
                                 {
                                     expression = Expression.AndAlso(filterValueNullCheck, expression);
                                 }
+                            }
 
                             innerExpression = innerExpression == null
                                 ? expression
@@ -253,8 +258,7 @@ namespace Sieve.Services
                 : result.Where(Expression.Lambda<Func<TEntity, bool>>(outerExpression, parameter));
         }
 
-        private static Expression GetFilterValueNullCheck(Expression parameter, string fullPropertyName,
-            bool isFilterTermValueNull)
+        private static Expression GetFilterValueNullCheck(Expression parameter, string fullPropertyName, bool isFilterTermValueNull)
         {
             var (propertyValue, nullCheck) = GetPropertyValueAndNullCheckExpression(parameter, fullPropertyName);
 
@@ -308,6 +312,10 @@ namespace Sieve.Services
         private static Expression ConvertStringValueToConstantExpression(string value, PropertyInfo property,
             TypeConverter converter)
         {
+            // to allow user to distinguish between prop==null (as null) and prop==\null (as "null"-string)
+            value = value.Equals(EscapeChar + NullFilterValue, StringComparison.InvariantCultureIgnoreCase) 
+                ? value.TrimStart(EscapeChar) 
+                : value;
             dynamic constantVal = converter.CanConvertFrom(typeof(string))
                 ? converter.ConvertFrom(value)
                 : Convert.ChangeType(value, property.PropertyType);
@@ -336,15 +344,13 @@ namespace Sieve.Services
         }
 
         // Workaround to ensure that the filter value gets passed as a parameter in generated SQL from EF Core
-        // See https://github.com/aspnet/EntityFrameworkCore/issues/3361
-        // Expression.Constant passed the target type to allow Nullable comparison
-        // See http://bradwilson.typepad.com/blog/2008/07/creating-nullab.html
         private static Expression GetClosureOverConstant<T>(T constant, Type targetType)
         {
-            return Expression.Constant(constant, targetType);
+            Expression<Func<T>> hoistedConstant = () => constant;
+            return Expression.Convert(hoistedConstant.Body, targetType);
         }
 
-        private IQueryable<TEntity> ApplySorting<TEntity>(TSieveModel model, IQueryable<TEntity> result,
+        protected virtual IQueryable<TEntity> ApplySorting<TEntity>(TSieveModel model, IQueryable<TEntity> result,
             object[] dataForCustomMethods = null)
         {
             if (model?.GetSortsParsed() == null)
@@ -373,11 +379,11 @@ namespace Sieve.Services
             return result;
         }
 
-        private IQueryable<TEntity> ApplyPagination<TEntity>(TSieveModel model, IQueryable<TEntity> result)
+        protected virtual IQueryable<TEntity> ApplyPagination<TEntity>(TSieveModel model, IQueryable<TEntity> result)
         {
             var page = model?.Page ?? 1;
-            var pageSize = model?.PageSize ?? _options.Value.DefaultPageSize;
-            var maxPageSize = _options.Value.MaxPageSize > 0 ? _options.Value.MaxPageSize : pageSize;
+            var pageSize = model?.PageSize ?? Options.Value.DefaultPageSize;
+            var maxPageSize = Options.Value.MaxPageSize > 0 ? Options.Value.MaxPageSize : pageSize;
 
             if (pageSize <= 0)
             {
@@ -399,14 +405,14 @@ namespace Sieve.Services
             string name)
         {
             var property = _mapper.FindProperty<TEntity>(canSortRequired, canFilterRequired, name,
-                _options.Value.CaseSensitive);
+                Options.Value.CaseSensitive);
             if (property.Item1 != null)
             {
                 return property;
             }
 
             var prop = FindPropertyBySieveAttribute<TEntity>(canSortRequired, canFilterRequired, name,
-                _options.Value.CaseSensitive);
+                Options.Value.CaseSensitive);
             return (prop?.Name, prop);
         }
 
@@ -426,7 +432,7 @@ namespace Sieve.Services
         {
             var customMethod = parent?.GetType()
                 .GetMethodExt(name,
-                    _options.Value.CaseSensitive
+                    Options.Value.CaseSensitive
                         ? BindingFlags.Default
                         : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance,
                     typeof(IQueryable<TEntity>));
@@ -437,7 +443,7 @@ namespace Sieve.Services
                 // Find generic methods `public IQueryable<T> Filter<T>(IQueryable<T> source, ...)`
                 var genericCustomMethod = parent?.GetType()
                     .GetMethodExt(name,
-                        _options.Value.CaseSensitive
+                        Options.Value.CaseSensitive
                             ? BindingFlags.Default
                             : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance,
                         typeof(IQueryable<>));
@@ -481,11 +487,11 @@ namespace Sieve.Services
                 var incompatibleCustomMethods =
                     parent?
                         .GetType()
-                        .GetMethods(_options.Value.CaseSensitive
+                        .GetMethods(Options.Value.CaseSensitive
                             ? BindingFlags.Default
                             : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance)
                         .Where(method => string.Equals(method.Name, name,
-                            _options.Value.CaseSensitive
+                            Options.Value.CaseSensitive
                                 ? StringComparison.InvariantCulture
                                 : StringComparison.InvariantCultureIgnoreCase))
                         .ToList()

SieveUnitTests/Abstractions/Entity/SieveConfigurationForIPost.cs

@@ -0,0 +1,37 @@
+using Sieve.Services;
+
+namespace SieveUnitTests.Abstractions.Entity
+{
+    public class SieveConfigurationForIPost : ISieveConfiguration
+    {
+        public void Configure(SievePropertyMapper mapper)
+        {
+            mapper.Property<IPost>(p => p.ThisHasNoAttributeButIsAccessible)
+                .CanSort()
+                .CanFilter()
+                .HasName("shortname");
+            
+            mapper.Property<IPost>(p => p.TopComment.Text)
+                .CanFilter();
+
+            mapper.Property<IPost>(p => p.TopComment.Id)
+                .CanSort();
+
+            mapper.Property<IPost>(p => p.OnlySortableViaFluentApi)
+                .CanSort();
+
+            mapper.Property<IPost>(p => p.TopComment.Text)
+                .CanFilter()
+                .HasName("topc");
+
+            mapper.Property<IPost>(p => p.FeaturedComment.Text)
+                .CanFilter()
+                .HasName("featc");
+
+            mapper
+                .Property<IPost>(p => p.DateCreated)
+                .CanSort()
+                .HasName("CreateDate");
+        }
+    }
+}

SieveUnitTests/Entities/SieveConfigurationForPost.cs

@@ -0,0 +1,37 @@
+using Sieve.Services;
+
+namespace SieveUnitTests.Entities
+{
+    public class SieveConfigurationForPost : ISieveConfiguration
+    {
+        public void Configure(SievePropertyMapper mapper)
+        {
+            mapper.Property<Post>(p => p.ThisHasNoAttributeButIsAccessible)
+                .CanSort()
+                .CanFilter()
+                .HasName("shortname");
+
+            mapper.Property<Post>(p => p.TopComment.Text)
+                .CanFilter();
+
+            mapper.Property<Post>(p => p.TopComment.Id)
+                .CanSort();
+
+            mapper.Property<Post>(p => p.OnlySortableViaFluentApi)
+                .CanSort();
+
+            mapper.Property<Post>(p => p.TopComment.Text)
+                .CanFilter()
+                .HasName("topc");
+
+            mapper.Property<Post>(p => p.FeaturedComment.Text)
+                .CanFilter()
+                .HasName("featc");
+
+            mapper
+                .Property<Post>(p => p.DateCreated)
+                .CanSort()
+                .HasName("CreateDate");
+        }
+    }
+}

SieveUnitTests/General.cs

@@ -15,16 +15,24 @@ namespace SieveUnitTests
     {
         private readonly ITestOutputHelper _testOutputHelper;
         private readonly SieveProcessor _processor;
+        private readonly SieveProcessor _nullableProcessor;
         private readonly IQueryable<Post> _posts;
         private readonly IQueryable<Comment> _comments;
 
         public General(ITestOutputHelper testOutputHelper)
         {
+            var nullableAccessor = new SieveOptionsAccessor();
+            nullableAccessor.Value.IgnoreNullsOnNotEqual = false;
+
             _testOutputHelper = testOutputHelper;
             _processor = new ApplicationSieveProcessor(new SieveOptionsAccessor(),
                 new SieveCustomSortMethods(),
                 new SieveCustomFilterMethods());
 
+            _nullableProcessor = new ApplicationSieveProcessor(nullableAccessor,
+                new SieveCustomSortMethods(),
+                new SieveCustomFilterMethods());
+
             _posts = new List<Post>
             {
                 new Post
@@ -65,7 +73,7 @@ namespace SieveUnitTests
                     CategoryId = 2,
                     TopComment = new Comment { Id = 1, Text = "D1" },
                     FeaturedComment = new Comment { Id = 7, Text = "D2" }
-                },
+                }
             }.AsQueryable();
 
             _comments = new List<Comment>
@@ -180,8 +188,25 @@ namespace SieveUnitTests
             };
 
             var result = _processor.Apply(model, _posts);
+            var nullableResult = _nullableProcessor.Apply(model, _posts);
 
             Assert.True(result.Count() == 2);
+            Assert.True(nullableResult.Count() == 2);
+        }
+
+        [Fact]
+        public void CanFilterNullableIntsWithNotEqual()
+        {
+            var model = new SieveModel()
+            {
+                Filters = "CategoryId!=1"
+            };
+
+            var result = _processor.Apply(model, _posts);
+            var nullableResult = _nullableProcessor.Apply(model, _posts);
+
+            Assert.True(result.Count() == 1);
+            Assert.True(nullableResult.Count() == 2);
         }
 
         [Theory]
@@ -613,5 +638,162 @@ namespace SieveUnitTests
             Assert.Equal(1,posts[2].Id);
             Assert.Equal(0,posts[3].Id);
         }
+
+        [Fact]
+        public void CanFilter_WithEscapeCharacter()
+        {
+            var comments = new List<Comment>
+            {
+                new Comment
+                {
+                    Id = 0,
+                    DateCreated = DateTimeOffset.UtcNow,
+                    Text = "Here is, a comment"
+                },
+                new Comment
+                {
+                    Id = 1,
+                    DateCreated = DateTimeOffset.UtcNow.AddDays(-1),
+                    Text = "Here is, another comment"
+                },
+            }.AsQueryable();
+
+            var model = new SieveModel
+            {
+                Filters = "Text==Here is\\, another comment"
+            };
+
+            var result = _processor.Apply(model, comments);
+            Assert.Equal(1, result.Count());
+        }
+
+        [Fact]
+        public void OrEscapedPipeValueFilteringWorks()
+        {
+            var comments = new List<Comment>
+            {
+                new Comment
+                {
+                    Id = 0,
+                    DateCreated = DateTimeOffset.UtcNow,
+                    Text = "Here is | a comment"
+                },
+                new Comment
+                {
+                    Id = 1,
+                    DateCreated = DateTimeOffset.UtcNow.AddDays(-1),
+                    Text = "Here is | another comment"
+                },
+                new Comment
+                {
+                    Id = 2,
+                    DateCreated = DateTimeOffset.UtcNow.AddDays(-1),
+                    Text = @"Here is \| another comment(1)"
+                }
+            }.AsQueryable();
+
+            var model = new SieveModel
+            {
+                Filters = @"Text==Here is \| a comment|Here is \| another comment|Here is \\\| another comment(1)",
+            };
+
+            var result = _processor.Apply(model, comments);
+            Assert.Equal(3, result.Count());
+        }
+        
+        [Theory]
+        [InlineData("CategoryId==1,(CategoryId|LikeCount)==50")]
+        [InlineData("(CategoryId|LikeCount)==50,CategoryId==1")]
+        public void CanFilterWithEscape(string filter)
+        {
+            var model = new SieveModel
+            {
+                Filters = filter
+            };
+
+            var result = _processor.Apply(model, _posts);
+            var entry = result.FirstOrDefault();
+            var resultCount = result.Count();
+
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+        }
+        
+        [Theory]
+        [InlineData(@"Title@=\\")]
+        public void CanFilterWithEscapedBackSlash(string filter)
+        {
+            var posts = new List<Post>
+            {
+                new Post
+                {
+                    Id = 1,
+                    Title = "E\\",
+                    LikeCount = 4,
+                    IsDraft = true,
+                    CategoryId = 1,
+                    TopComment = new Comment { Id = 1, Text = "E1" },
+                    FeaturedComment = new Comment { Id = 7, Text = "E2" }
+                }
+            }.AsQueryable();
+            
+            var model = new SieveModel
+            {
+                Filters = filter
+            };
+
+            var result = _processor.Apply(model, posts);
+            var entry = result.FirstOrDefault();
+            var resultCount = result.Count();
+
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+        }
+        
+        [Theory]
+        [InlineData(@"Title@=\== ")]
+        [InlineData(@"Title@=\!= ")]
+        [InlineData(@"Title@=\> ")]
+        [InlineData(@"Title@=\< ")]
+        [InlineData(@"Title@=\<= ")]
+        [InlineData(@"Title@=\>= ")]
+        [InlineData(@"Title@=\@= ")]
+        [InlineData(@"Title@=\_= ")]
+        [InlineData(@"Title@=!\@= ")]
+        [InlineData(@"Title@=!\_= ")]
+        [InlineData(@"Title@=\@=* ")]
+        [InlineData(@"Title@=\_=* ")]
+        [InlineData(@"Title@=\==* ")]
+        [InlineData(@"Title@=\!=* ")]
+        [InlineData(@"Title@=!\@=* ")]
+        public void CanFilterWithEscapedOperators(string filter)
+        {
+            var posts = new List<Post>
+            {
+                new Post
+                {
+                    Id = 1,
+                    Title = @"Operators: == != > < >= <= @= _= !@= !_= @=* _=* ==* !=* !@=* !_=* ",
+                    LikeCount = 1,
+                    IsDraft = true,
+                    CategoryId = 1,
+                    TopComment = new Comment { Id = 1, Text = "F1" },
+                    FeaturedComment = new Comment { Id = 7, Text = "F2" }
+                }
+            }.AsQueryable();
+            
+            var model = new SieveModel
+            {
+                Filters = filter,
+            };
+
+            var result = _processor.Apply(model, posts);
+            var entry = result.FirstOrDefault();
+            var resultCount = result.Count();
+
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+        }
+        
     }
 }

SieveUnitTests/GeneralWithInterfaces.cs

@@ -16,16 +16,24 @@ namespace SieveUnitTests
     {
         private readonly ITestOutputHelper _testOutputHelper;
         private readonly SieveProcessor _processor;
+        private readonly SieveProcessor _nullableProcessor;
         private readonly IQueryable<IPost> _posts;
         private readonly IQueryable<Comment> _comments;
 
         public GeneralWithInterfaces(ITestOutputHelper testOutputHelper)
         {
+            var nullableAccessor = new SieveOptionsAccessor();
+            nullableAccessor.Value.IgnoreNullsOnNotEqual = false;
+
             _testOutputHelper = testOutputHelper;
             _processor = new ApplicationSieveProcessor(new SieveOptionsAccessor(),
                 new SieveCustomSortMethods(),
                 new SieveCustomFilterMethods());
 
+            _nullableProcessor = new ApplicationSieveProcessor(nullableAccessor,
+                new SieveCustomSortMethods(),
+                new SieveCustomFilterMethods());
+
             _posts = new List<IPost>
             {
                 new Post
@@ -181,8 +189,25 @@ namespace SieveUnitTests
             };
 
             var result = _processor.Apply(model, _posts);
+            var nullableResult = _nullableProcessor.Apply(model, _posts);
 
             Assert.True(result.Count() == 2);
+            Assert.True(nullableResult.Count() == 2);
+        }
+
+        [Fact]
+        public void CanFilterNullableIntsWithNotEqual()
+        {
+            var model = new SieveModel()
+            {
+                Filters = "CategoryId!=1"
+            };
+
+            var result = _processor.Apply(model, _posts);
+            var nullableResult = _nullableProcessor.Apply(model, _posts);
+
+            Assert.True(result.Count() == 1);
+            Assert.True(nullableResult.Count() == 2);
         }
 
         [Fact]

SieveUnitTests/Mapper.cs

@@ -2,6 +2,7 @@ using System.Collections.Generic;
 using System.Linq;
 using Sieve.Exceptions;
 using Sieve.Models;
+using Sieve.Services;
 using SieveUnitTests.Entities;
 using SieveUnitTests.Services;
 using Xunit;
@@ -10,15 +11,10 @@ namespace SieveUnitTests
 {
     public class Mapper
     {
-        private readonly ApplicationSieveProcessor _processor;
         private readonly IQueryable<Post> _posts;
 
         public Mapper()
         {
-            _processor = new ApplicationSieveProcessor(new SieveOptionsAccessor(),
-                new SieveCustomSortMethods(),
-                new SieveCustomFilterMethods());
-
             _posts = new List<Post>
             {
                 new Post
@@ -45,23 +41,49 @@ namespace SieveUnitTests
             }.AsQueryable();
         }
 
-        [Fact]
-        public void MapperWorks()
+        /// <summary>
+        /// Processors with the same mappings but configured via a different method.
+        /// </summary>
+        /// <returns></returns>
+        public static IEnumerable<object[]> GetProcessors()
+        {
+            yield return new object[] { 
+                new ApplicationSieveProcessor(
+                    new SieveOptionsAccessor(),
+                    new SieveCustomSortMethods(),
+                    new SieveCustomFilterMethods())};
+            yield return new object[] { 
+                new ModularConfigurationSieveProcessor(
+                    new SieveOptionsAccessor(),
+                    new SieveCustomSortMethods(),
+                    new SieveCustomFilterMethods())};
+            yield return new object[] { 
+                new ModularConfigurationWithScanSieveProcessor(
+                    new SieveOptionsAccessor(),
+                    new SieveCustomSortMethods(),
+                    new SieveCustomFilterMethods())};
+        }
+        
+        
+        [Theory]
+        [MemberData(nameof(GetProcessors))]
+        public void MapperWorks(ISieveProcessor processor)
         {
             var model = new SieveModel
             {
                 Filters = "shortname@=A",
             };
 
-            var result = _processor.Apply(model, _posts);
+            var result = processor.Apply(model, _posts);
 
             Assert.Equal("A", result.First().ThisHasNoAttributeButIsAccessible);
 
             Assert.True(result.Count() == 1);
         }
 
-        [Fact]
-        public void MapperSortOnlyWorks()
+        [Theory]
+        [MemberData(nameof(GetProcessors))]
+        public void MapperSortOnlyWorks(ISieveProcessor processor)
         {
             var model = new SieveModel
             {
@@ -69,9 +91,9 @@ namespace SieveUnitTests
                 Sorts = "OnlySortableViaFluentApi"
             };
 
-            var result = _processor.Apply(model, _posts, applyFiltering: false, applyPagination: false);
+            var result = processor.Apply(model, _posts, applyFiltering: false, applyPagination: false);
 
-            Assert.Throws<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
+            Assert.Throws<SieveMethodNotFoundException>(() => processor.Apply(model, _posts));
 
             Assert.Equal(3, result.First().Id);
 

SieveUnitTests/Services/ModularConfigurationSieveProcessor.cs

@@ -0,0 +1,26 @@
+using Microsoft.Extensions.Options;
+using Sieve.Models;
+using Sieve.Services;
+using SieveUnitTests.Abstractions.Entity;
+using SieveUnitTests.Entities;
+
+namespace SieveUnitTests.Services
+{
+    public class ModularConfigurationSieveProcessor : SieveProcessor
+    {
+        public ModularConfigurationSieveProcessor(
+            IOptions<SieveOptions> options,
+            ISieveCustomSortMethods customSortMethods,
+            ISieveCustomFilterMethods customFilterMethods)
+            : base(options, customSortMethods, customFilterMethods)
+        {
+        }
+
+        protected override SievePropertyMapper MapProperties(SievePropertyMapper mapper)
+        {
+            return mapper
+                .ApplyConfiguration<SieveConfigurationForPost>()
+                .ApplyConfiguration<SieveConfigurationForIPost>();
+        }
+    }
+}

SieveUnitTests/Services/ModularConfigurationWithScanSieveProcessor.cs

@@ -0,0 +1,20 @@
+using Microsoft.Extensions.Options;
+using Sieve.Models;
+using Sieve.Services;
+
+namespace SieveUnitTests.Services
+{
+    public class ModularConfigurationWithScanSieveProcessor : SieveProcessor
+    {
+        public ModularConfigurationWithScanSieveProcessor(
+            IOptions<SieveOptions> options,
+            ISieveCustomSortMethods customSortMethods,
+            ISieveCustomFilterMethods customFilterMethods)
+            : base(options, customSortMethods, customFilterMethods)
+        {
+        }
+
+        protected override SievePropertyMapper MapProperties(SievePropertyMapper mapper) => 
+            mapper.ApplyConfigurationsFromAssembly(typeof(ModularConfigurationWithScanSieveProcessor).Assembly);
+    }
+}

SieveUnitTests/StringFilterNullTests.cs

@@ -38,7 +38,7 @@ namespace SieveUnitTests
                 {
                     Id = 2, 
                     DateCreated = DateTimeOffset.UtcNow, 
-                    Text = "Regular comment without n*ll.",
+                    Text = "Regular comment without n*ll",
                     Author = "Mouse",
                 },
                 new Comment
@@ -47,24 +47,28 @@ namespace SieveUnitTests
                     DateCreated = DateTimeOffset.UtcNow, 
                     Text = null,
                     Author = "null",
-                },
+                }
             }.AsQueryable();
         }
 
-        [Fact]
-        public void Filter_Equals_Null()
+        [Theory]
+        [InlineData("Text==null")]
+        [InlineData("Text==*null")]
+        public void Filter_Equals_Null(string filter)
         {
-            var model = new SieveModel {Filters = "Text==null"};
+            var model = new SieveModel {Filters = filter};
 
             var result = _processor.Apply(model, _comments);
 
             Assert.Equal(100, result.Single().Id);
         }
 
-        [Fact]
-        public void Filter_NotEquals_Null()
+        [Theory]
+        [InlineData("Text!=null")]
+        [InlineData("Text!=*null")]
+        public void Filter_NotEquals_Null(string filter)
         {
-            var model = new SieveModel {Filters = "Text!=null"};
+            var model = new SieveModel {Filters = filter};
 
             var result = _processor.Apply(model, _comments);
 
@@ -101,6 +105,22 @@ namespace SieveUnitTests
             Assert.Equal(expectedIds, result.Select(p => p.Id));
         }
 
+        [Theory]
+        [InlineData(@"Author==\null", 100)]
+        [InlineData(@"Author==*\null", 100)]
+        [InlineData(@"Author==*\NuLl", 100)]
+        [InlineData(@"Author!=*\null", 0, 1, 2)]
+        [InlineData(@"Author!=*\NulL", 0, 1, 2)]
+        [InlineData(@"Author!=\null", 0, 1, 2)]
+        public void SingleFilter_Equals_NullStringEscaped(string filter, params int[] expectedIds)
+        {
+            var model = new SieveModel {Filters = filter};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(expectedIds, result.Select(p => p.Id));
+        }
+
         [Theory]
         [InlineData("Text_=null")]
         [InlineData("Text_=*null")]

build/Build.cs

@@ -1,4 +1,5 @@
 using System.Linq;
+using GlobExpressions;
 using Nuke.Common;
 using Nuke.Common.CI;
 using Nuke.Common.CI.GitHubActions;
@@ -8,17 +9,24 @@ using Nuke.Common.IO;
 using Nuke.Common.ProjectModel;
 using Nuke.Common.Tools.DotNet;
 using Nuke.Common.Tools.GitVersion;
+using Nuke.Common.Utilities.Collections;
 using static Nuke.Common.IO.FileSystemTasks;
 using static Nuke.Common.Tools.DotNet.DotNetTasks;
 
 [CheckBuildProjectConfigurations]
 [ShutdownDotNetAfterServerBuild]
 [GitHubActions("ci", GitHubActionsImage.UbuntuLatest,
-    OnPushBranches = new[] {"master"},
-    OnPullRequestBranches = new[] {"master"},
+    OnPullRequestBranches = new[] {"master", "releases/*"},
     AutoGenerate = true,
     InvokedTargets = new[] {nameof(Ci)},
     CacheKeyFiles = new string[0])]
+[GitHubActions("ci_publish", GitHubActionsImage.UbuntuLatest,
+    OnPushBranches = new[] { "releases/*" },
+    OnPushTags = new[] { "v*" },
+    AutoGenerate = true,
+    InvokedTargets = new[] {nameof(CiPublish)},
+    CacheKeyFiles = new string[0],
+    ImportSecrets = new[] {"NUGET_API_KEY"})]
 class Build : NukeBuild
 {
     [Parameter("Configuration to build - Default is 'Debug' (local) or 'Release' (server)")]
@@ -30,6 +38,9 @@ class Build : NukeBuild
 
     [Solution] readonly Solution Solution;
 
+    // ReSharper disable once InconsistentNaming
+    [Parameter] string NUGET_API_KEY;
+
     Project SieveProject => Solution.AllProjects.First(p => p.Name == "Sieve");
 
     AbsolutePath OutputDirectory => RootDirectory / "output";
@@ -73,6 +84,7 @@ class Build : NukeBuild
     Target Package => _ => _
         .DependsOn(Test)
         .Executes(() =>
+        
         {
             DotNetPack(s => s
                 .SetProject(SieveProject)
@@ -83,13 +95,29 @@ class Build : NukeBuild
                 .EnableNoBuild());
         });
 
-    Target Ci => _ => _
-        .DependsOn(Package);
+    Target Publish => _ => _
+        .DependsOn(Package)
+        .Requires(() => IsServerBuild)
+        .Requires(() => NUGET_API_KEY)
+        .Requires(() => Configuration.Equals(Configuration.Release))
+        .Executes(() =>
+        {
+            Glob.Files(OutputDirectory, "*.nupkg")
+                .NotEmpty()
+                .ForEach(x =>
+                {
+                    DotNetNuGetPush(s => s
+                        .SetTargetPath(OutputDirectory / x)
+                        .SetSource("https://api.nuget.org/v3/index.json")
+                        .SetApiKey(NUGET_API_KEY));
+                });
+        });
+
+    Target Ci => _ => _
+        .DependsOn(Test);
+
+    Target CiPublish => _ => _
+        .DependsOn(Publish);
 
-    /// Support plugins are available for:
-    /// - JetBrains ReSharper        https://nuke.build/resharper
-    /// - JetBrains Rider            https://nuke.build/rider
-    /// - Microsoft VisualStudio     https://nuke.build/visualstudio
-    /// - Microsoft VSCode           https://nuke.build/vscode
     public static int Main() => Execute<Build>(x => x.Package);
 }