Plainquire.Filter 5.2.0

Plainquire

Easy filtering, sorting and paging for ASP.NET Core.

Dynamically creates required expressions to filter, sort and page enumerable and database queries using LINQ.

Features

• Filtering, sorting and pagination for ASP.NET Core
• Customizable syntax
• Support for Swagger / OpenUI and code generators via Swashbuckle.AspNetCore
• Support for Entity Framework an other ORM mapper using IQueryable<T>
• Support for In-memory lists / arrays via IEnumerable<T>
• Binding for HTTP query parameters
• Natural language date/time interpretation (e.g. yesterday, last week Tuesday, ...)
• Filters, sorts and pages are serializable, e.g. to persist user defined filters
• Customizable expressions via interceptors

Demo

https://www.plainquire.com/demo

https://www.plainquire.com/api

Overview

HTTP request (Syntax: Filter Operators / Syntax)

BASE_URL=https://www.plainquire.com/api/Freelancer
curl -O "$BASE_URL/GetFreelancers?firstName=Joe&orderBy=lastName&page=3&pageSize=5"

MVC action

[HttpGet]
public List<FreelancerDto> GetFreelancers(
    [FromQuery] EntityFilter<Freelancer> filter,
    [FromQuery] EntitySort<Freelancer> sort,
    [FromQuery] EntityPage page)
{
    return dbContext.Freelancers
        .Where(filter)
        .OrderBy(sort)
        .Page(page);
}

Results in SQL statement (SQLite syntax)

SELECT *
FROM "Freelancer"
WHERE instr(upper("FirstName"), 'JOE') > 0
ORDER BY "LastName"
LIMIT 5 OFFSET 10

Table of contents

• Getting started
• Syntax
• Filter entities
  • Basic usage
  • Filter by special values
  • Logical Operators
  • Nested filters
  • Retrieve syntax and filter values
  • REST / MVC
  • Swagger / OpenAPI
  • Support for Newtonsoft.Json
  • Configuration
  • Interception
  • Advanced scenarios
• Sort entities
  • Basic usage
  • Add sorting
  • Nested sorting
  • Retrieve syntax and sort direction
  • REST / MVC
  • Swagger / OpenAPI
  • Support for Newtonsoft.Json
  • Configuration
  • Interception
  • Advanced scenarios
• Page Entities
  • Basic usage
  • REST / MVC
  • Swagger / OpenAPI
  • Support for Newtonsoft.Json
  • Configuration
  • Interception
  • Advanced Scenarios
• Upgrade from FilterExpressionCreator

Getting started

Web / MVC application

dotnet add package Plainquire.Filter
dotnet add package Plainquire.Filter.Mvc
dotnet add package Plainquire.Filter.Swashbuckle
dotnet add package Plainquire.Page
dotnet add package Plainquire.Page.Mvc
dotnet add package Plainquire.Page.Swashbuckle
dotnet add package Plainquire.Sort
dotnet add package Plainquire.Sort.Mvc
dotnet add package Plainquire.Sort.Swashbuckle

using Plainquire.Filter.Mvc;
using Plainquire.Filter.Swashbuckle;
using Plainquire.Page.Mvc;
using Plainquire.Page.Swashbuckle;
using Plainquire.Sort.Mvc;
using Plainquire.Sort.Swashbuckle;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers()
    .AddFilterSupport()
    .AddSortSupport()
    .AddPageSupport();

builder.Services.AddSwaggerGen(options => options
    .AddFilterSupport()
    .AddSortSupport()
    .AddPageSupport());

using Plainquire.Filter;
using Plainquire.Page;
using Plainquire.Sort;

[EntityFilter]
public record Order(int Number, string Customer);

[HttpGet(Name = "GetOrders")]
public IEnumerable<Order> GetOrders(
    [FromQuery] EntityFilter<Order> filter,
    [FromQuery] EntitySort<Order> sort,
    [FromQuery] EntityPage page)
{
    var orders = GenerateOrders(); // See code below
    var requestedOrders = orders.Where(filter).OrderBy(sort).Page(page);
    return requestedOrders;
}

Non-web application

dotnet add package Plainquire.Filter
dotnet add package Plainquire.Sort
dotnet add package Plainquire.Page

using Plainquire.Filter;
using Plainquire.Sort;
using Plainquire.Page;

[EntityFilter]
public record Order(int Number, string Customer);

public IEnumerable<Order> GetOrders()
{
    var orders = GenerateOrders(); // See code below

    var filter = new EntityFilter<Order>().Add(x => x.Customer, "~Santos");
    var sort = new EntitySort<Order>().Add(x => x.Customer, SortDirection.Ascending);
    var page = new EntityPage { PageNumber = 2, PageSize = 3 };

    var requestedOrders = orders.Where(filter).OrderBy(sort).Page(page);
    return requestedOrders;
}

Generate sample orders

private static readonly string[] _customerNames =
[
    "Brock Luettgen",
    "Santos Rath",
    "Camden Goldner",
    "Santos Marks"
];

private static List<Order> GenerateOrders()
{
    return Enumerable
        .Range(1, 5)
        .Select(index => new Order
        (
            Number: index,
            Customer: _customerNames[Random.Shared.Next(_customerNames.Length)]
        ))
        .ToList();
}

Syntax

Filter syntax

Samples (HTTP query parameter)

Query parameter	Description
gender=male,female	Gender equals male OR female
gender=~male	Gender contains male (fetches female too)
size=<100	Size is lower than 100
size=>100&size<200	Size is between 100 and 200
created=>two-days-ago	Created within the last 2 days
created=yesterday	Created yesterday
created=>2020-03	Created after Sunday, March 1, 2020
created=2020	Crated in the year 2020
name=	Name equals ""

Reference

The filter micro syntax consists of a comma separated list of an operator and value (e.g. ~Joe,=Doe). Commas within a value can be escaped with a backslash.

Comma separated values are combined with logical OR. To combine values with logical AND, specify the filter multiple times.

Operator	Micro syntax	Description
Default		Selects the operator according to the filtered type. When filtering string the default is Contains; otherwise EqualCaseInsensitive
Contains	~	Hits when the filtered property contains the filter value
EqualCaseInsensitive	=	Hits when the filtered property equals the filter value (case-insensitive)
EqualCaseSensitive	==	Hits when the filtered property equals the filter value (case-sensitive)
NotEqual	!	Negates the Default operator. Operators other than Default cannot be negated (currently)
LessThan	<	Hits when the filtered property is less than the filter value
LessThanOrEqual	⇐	Hits when the filtered property is less than or equal to the filter value
GreaterThan	>	Hits when the filtered property is greater than the filter value
GreaterThanOrEqual	>=	Hits when the filtered property is greater than or equals the filter value
IsNull	ISNULL	Hits when the filtered property is null
NotNull	NOTNULL	Hits when the filtered property is not null

Sort syntax

Samples (HTTP query parameter)

Query parameter	Description
orderBy=lastName	Sort by lastName ascending
orderBy=lastName-	Sort by lastName descending
orderBy=lastName,-firstName	Sort by lastName ascending, than by firstName descending
orderBy=lastName.length	Sort by length of lastName ascending

Reference

The sort micro syntax consists of a property name to sort with an optional sort direction marker before or after (e.g. customer-asc). For the HTTP query parameter, a comma separated list of properties is allowed (orderBy=customer,number-desc).

Position	Direction	Values
prefix	ascending	+, asc-, asc
postfix	ascending	+, -asc, asc
prefix	descending	-, ~, desc-, dsc-, desc , dsc
postfix	descending	-, ~, -desc, -dsc, desc, dsc

Filter entities

Basic usage

Install NuGet packages

Package Manager : Install-Package Plainquire.Filter
CLI : dotnet add package Plainquire.Filter

Create a filter

using Plainquire.Filter;

var orders = new[] {
   new Order { Customer = "Joe Miller", Number = 100 },
   new Order { Customer = "Joe Smith", Number = 200 },
   new Order { Customer = "Joe Smith", Number = 300 },
};

// Create filter
var filter = new EntityFilter<Order>()
   .Add(x => x.Customer, "Joe")
   .Add(x => x.Number, FilterOperator.GreaterThan, 250);

// Print filter
Console.WriteLine(filter);
// Output: x => (((x.Customer != null) AndAlso x.Customer.ToUpper().Contains("JOE")) AndAlso (x.Number > 250))

// Use filter with LINQ
var filteredOrders = orders.Where(filter).ToList();
// Or queryables (e.g. Entity Framework)
var filteredOrders = dbContext.Orders.Where(filter).ToList();
// Output: new[] { new Order { Customer = "Joe Smith", Number = 300 } };

[EntityFilter]
public class Order
{
   public int Number { get; set; }
   public string Customer { get; set; }
}

Or bind sort from query-parameters

using Plainquire.Filter;

[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] EntityFilter<Order> order)
{
    return dbContext.Orders.Where(filter).ToList();
}

Filter by special values

Filter by == null / != null

// For 'Customer is null'
filter.Add(x => x.Customer, FilterOperator.IsNull);
// Output: x => (x.Customer == null)

// For 'Customer is not null'
filter.Add(x => x.Customer, FilterOperator.NotNull);
// Output: x => (x.Customer != null)

// via query parameter
var getOrdersUrl = "/GetOrders?customer=ISNULL"
var getOrdersUrl = "/GetOrders?customer=NOTNULL"

While filtered for == null / != null, (accidently) given values are ignored:

filter.Add(x => x.Customer, FilterOperator.NotNull, "values", "are", "ignored");

Filter by "" / string.Empty

// For 'Customer == ""'
filter.Add(x => x.Customer, string.Empty);
// Output: x => (x.Customer == "")

// For 'Customer is not null'
filter.Add(x => x.Customer, FilterOperator.NotEqual, string.Empty);
// Output: x => (x.Customer != "")

// via query parameter
var getOrdersUrl = "/GetOrders?customer="

Filter by Date/Time

Date/Time values can be given in the form of a fault-tolerant round-trip date/time pattern

// Date
filter.Add(x => x.Created, ">2020/01/01");
// Output: x => (x.Created > 01.01.2020 00:00:00)

// Date/Time
filter.Add(x => x.Created, ">2020-01-01-12-30");
// Output: x => (x.Created > 01.01.2020 12:30:00)

// Partial values are supported too
filter.Add(x => x.Created, "2020-01");
// Output: x => ((x.Created >= 01.01.2020 00:00:00) AndAlso (x.Created < 01.02.2020 00:00:00))

Filter by Date/Time with natural language

Thanks to nChronic.Core natural language for date/time is supported.

// This
filter.Add(x => x.Created, ">yesterday");

// works as well as
filter.Add(x => x.Created, ">3-months-ago-saturday-at-5-pm");

Details can be found here: https://github.com/mojombo/chronic

Filter by enum

Enum values can be filtered by its name as well as by it's numeric representation.

// Equals by name
filter.Add(x => x.Gender, "=divers");
// Output: x => (x.Gender == Divers)

// Equals by numeric value
filter.Add(x => x.Gender, "=1");
// Output: x => (Convert(x.Gender, Int64) == 1)

// Contains, value is expanded
filter.Add(x => x.Gender, "~male");
// Output: x => ((x.Gender == Male) OrElse (x.Gender == Female))

enum Gender { Divers, Male, Female }

Filter by numbers

Filter for numbers support contains operator but may be less performant.

// Equals
filter.Add(x => x.Number, "1");
// Output: x => (x.Number == 1)

// Contains
filter.Add(x => x.Number, "~1");
// Output: x => x.Number.ToString().ToUpper().Contains("1")

Syntax examples

Syntax	Description
Joe	For string filtered value contains 'Joe', for Enum filtered value is 'Joe'
~Joe	Filtered value contains 'Joe', even for Enum
~1,~2	Filtered value contains 1 or 2
=1\,2	Filtered value equals 1,2
~Joe,=Doe	Filtered value contains Joe or equals Doe
<4,>10	Filtered value is less than 4 or greater than 10
ISNULL	Filtered value is null
>one-week-ago	For DateTime filtered value is greater than one week ago
2020	For DateTime filtered value is between 01/01/2020 and 12/31/2020
2020-01	For DateTime filtered value is between 01/01/2020 and 1/31/2020

Logical Operators

Add/Replace filter using logical OR

Multiple values given to one call are combined using conditional OR.

// Customer contains `Joe` || `Doe`

var filter = new EntityFilter<Order>();

// via operator
filter.Add(x => x.Customer, FilterOperator.Contains, "Joe", "Doe");
filter.Replace(x => x.Customer, FilterOperator.Contains, "Joe", "Doe");

// via syntax
filter.Add(x => x.Customer, "~Joe,~Doe");
filter.Replace(x => x.Customer, "~Joe,~Doe");

// via query parameter
var getOrdersUrl = "/GetOrders?customer=~Joe,~Doe"

Add/Replace filter using logical AND

Multiple calls are combined using conditional AND.

// Customer contains `Joe` && `Doe`

var filter = new EntityFilter<Order>();

// via operator
filter
    .Add(x => x.Customer, FilterOperator.Contains, "Joe")
    .Add(x => x.Customer, FilterOperator.Contains, "Doe");

// via syntax
filter
    .Add(x => x.Customer, "~Joe")
    .Add(x => x.Customer, "~Doe");

// via query parameter
var getOrdersUrl = "/GetOrders?customer=~Joe&customer=~Doe"

Nested filters

Nested objects are filtered directly (x => x.Address.City == "Berlin")

Nested lists are filtered using .Any() (x => x.Items.Any(item => (item.Article == "Laptop")))

// Create filters
var addressFilter = new EntityFilter<Address>()
    .Add(x => x.City, "==Berlin");

var itemFilter = new EntityFilter<OrderItem>()
    .Add(x => x.Article, "==Laptop");

var orderFilter = new EntityFilter<Order>()
    .AddNested(x => x.Address, addressFilter)
    .AddNested(x => x.Items, itemFilter);

// Print filter
Console.WriteLine(orderFilter);
// Output:
// x => ((x.Address != null) AndAlso (x.Address.City == "Berlin"))
// x => ((x.Items != null) AndAlso x.Items.Any(x => (x.Article == "Laptop")))

public class Order
{
    public int Number { get; set; }
    public string Customer { get; set; }

    public Address Address { get; set; }
    public List<OrderItem> Items { get; set; }
}

public record Address(string Street, string City);
public record OrderItem(int Position, string Article);

Retrieve syntax and filter values

var filter = new EntityFilter<Order>()
    .Add(x => x.Customer, FilterOperator.Contains, "Joe", "Doe");

// Retrive filter syntax
string filterSytax = filter.GetPropertyFilterSyntax(x => x.Customer);
// Output: ~Joe,~Doe

// Retrive filter values
ValueFilter[] filterValues = filter.GetPropertyFilterValues(x => x.Customer);
// Output:
// [{
//   "Operator": "Contains",
//   "Value": "Joe",
//   "IsEmpty": false
// }, {
//   "Operator": "Contains",
//   "Value": "Doe",
//   "IsEmpty": false
// }]

REST / MVC

To filter an entity via model binding, the entity must be marked with EntityFilterAttribute

Register model binders

Package Manager : Install-Package Plainquire.Filter.Mvc
CLI : dotnet add package Plainquire.Filter.Mvc

using Plainquire.Filter.Mvc;

// Register required stuff by calling 'AddFilterSupport()' on IMvcBuilder instance
services.AddControllers().AddFilterSupport();

Map HTTP query parameters to EntityFilter

With model binding enabled, REST requests can be filtered using query parameters:

using Plainquire.Filter;

var getOrdersUrl = "/GetOrders?customer==Joe&number=>4711"

[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] EntityFilter<Order> filter)
{
    Console.WriteLine(filter);
    // Output:
    // x => (
    //   ((x.Customer != null) AndAlso (x.Customer.ToUpper() == "JOE"))
    //   AndAlso (x.Number > 4711)
    // )

    var queryParams = filter.ToQueryParams();
    // Output: customer==Joe&number=>4711
}

Configure model binding

By default, parameters for properties of filtered entity are named {Entity}{Property}. By default, all public non-complex properties (string, int, DateTime, ...) are recognized. Parameters can be renamed or removed using FilterAttribute and EntityFilterAttribute.

For the code below Number is not mapped anymore and Customer becomes CustomerName:

using Plainquire.Filter.Abstractions;

// Remove prefix, e.g. property 'Number' is mapped from 'number', not 'orderNumber'
[EntityFilter(Prefix = "")]
public class Order
{
     // 'Number' is removed from filter and will be ignored
    [Filter(Filterable = false)]
    public int Number { get; set; }

    // 'Customer' is mapped from query-parameter 'customerName'
    [Filter(Name = "CustomerName")]
    public string Customer { get; set; }
}

Filter sets

Multiple entity filters can be combined to a set of filters using the EntityFilterSetAttribute.

using Plainquire.Filter;
using Plainquire.Filter.Abstractions;

// Use
[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] OrderFilterSet filterSet)
{
    var order = filterSet.Order;
    var orderItem = filterSet.OrderItem;
}

// Instead of
public Task<List<Order>> GetOrders([FromQuery] EntityFilter<Order> order, EntityFilter<OrderItem> orderItem) { ... }

[EntityFilterSet]
public class OrderFilterSet
{
    public EntityFilter<Order> Order { get; set; }
    public EntityFilter<OrderItem> OrderItem { get; set; }
}

Swagger / OpenAPI

Register OpenAPI support

Swagger / OpenAPI is supported when using Swashbuckle.AspNetCore.

Package Manager : Install-Package Plainquire.Filter.Swashbuckle
CLI : dotnet add package Plainquire.Filter.Swashbuckle

using Plainquire.Filter.Swashbuckle;

services.AddSwaggerGen(options =>
{
    // Register filters used to modify swagger.json
    options.AddFilterSupport();
});

Register XML documentation

To get descriptions for generated parameters from XML documentation, paths to documentation files can be provided.

services.AddSwaggerGen(options =>
{
    var filterDoc = Path.Combine(AppContext.BaseDirectory, "Plainquire.Filter.xml");
    options.AddFilterSupport(filterDoc);
    options.IncludeXmlComments(filterDoc);
});

Support for Newtonsoft.Json

By default System.Text.Json is used to serialize/convert Plainquire specific stuff. If you like to use Newtonsoft.Json you must register it:

Package Manager : Install-Package Plainquire.Filter.Mvc.Newtonsoft
CLI : dotnet add package Plainquire.Filter.Mvc.Newtonsoft

using Plainquire.Filter.Mvc.Newtonsoft;

// Register support for Newtonsoft by calling
// 'AddFilterNewtonsoftSupport()' on IMvcBuilder instance
services.AddControllers().AddFilterNewtonsoftSupport();

Configuration

Creation of filter expression can be configured via FilterConfiguration.

using Plainquire.Filter;

// Parse filter values using german locale (e.g. "5,5" => 5.5f).
var configuration = new FilterConfiguration { CultureInfo = new CultureInfo("de-DE") };

The configuration can be provided as follows and is used according to the listed order of precedence

// For MVC model binding via dependency injection
services.Configure<FilterConfiguration>(c => c.IgnoreParseExceptions = true);

// Via constructor
new EntityFilter<Order>(configuration);

// Via static default
FilterConfiguration.Default

Interception

Creation of filter expression can be intercepted via IFilterInterceptor. While implicit conversions to Func<TEntity, bool> and Expression<Func<TEntity, bool>> exists, explicit filter conversion is required to apply an interceptor.

var filter = new EntityFilter<Order>();
var interceptor = new FilterStringsCaseInsensitiveInterceptor();
var filterExpression = filter.CreateFilter(interceptor) ?? (x => true);
var filteredList = orders.Where(filterExpression.Compile());
var filteredDb = _dbContext.Orders.Where(filterExpression);

Default interceptor

A default interceptor can be provided via static IFilterInterceptor.Default.

Sample interceptor

Interceptor to omit filter values having an empty value. Allows to omit filters added by empty query parameters (&birthday=) but prevents filtering for empty strings (&name=).

public class OmitEmptyFilterInterceptor : IFilterInterceptor
{
    public Expression<Func<TEntity, bool>>? CreatePropertyFilter<TEntity>(PropertyInfo propertyInfo, IEnumerable<ValueFilter> filters, FilterConfiguration configuration)
    {
        var nonEmptyFilters = filters.Where(ValueIsNotNullOrEmpty).ToList();

        var noFilterRequired = nonEmptyFilters.Count == 0;
        return noFilterRequired
            ? PropertyFilterExpression.EmptyFilter<TEntity>()
            : PropertyFilterExpression.CreateFilter<TEntity>(propertyInfo, nonEmptyFilters, configuration, this);
    }

    private static bool ValueIsNotNullOrEmpty(ValueFilter valueFilter)
        => !string.IsNullOrEmpty(valueFilter.Value);

    Func<DateTimeOffset> IFilterInterceptor.Now => () => DateTimeOffset.Now;
}

Advanced scenarios

Deep copy

The EntityFilter<T> class supports deep cloning by calling the Clone() method

var copy = filter.Clone();

Casting

Filters can be cast between entities, e.g. to convert them between DTOs and database models.

Properties are matched by type (check if assignable) and name (case-sensitive)

var dtoFilter = new EntityFilter<OrderDto>().Add(...);
var orderFilter = dtoFilter.Cast<Order>();

Serialization

Using System.Text.Json

Objects of type EntityFilter<T> can be serialized via System.Text.Json.JsonSerializer without further requirements

var json = JsonSerializer.Serialize(filter);
filter = JsonSerializer.Deserialize<EntityFilter<Order>>(json);

Using Newtonsoft.Json

When using Newtonsoft.Json additional converters are required

Package Manager : Install-Package Plainquire.Filter.Newtonsoft
CLI : dotnet add package Plainquire.Filter.Newtonsoft

using Plainquire.Filter.Newtonsoft;

var json = JsonConvert.SerializeObject(filter, JsonConverterExtensions.NewtonsoftConverters);
filter = JsonConvert.DeserializeObject<EntityFilter<Order>>(json, JsonConverterExtensions.NewtonsoftConverters);

Combine filter expressions

To add custom checks to a filter either call .Where(...) again

var filteredOrders = orders
    .Where(filter)
    .Where(item => item.Items.Count > 2);

or where this isn't possible combine filters with CombineWithConditionalAnd

using Plainquire.Filter.Abstractions;

var extendedFilter = new[]
    {
        filter.CreateFilter(),
        item => item.Items.Count > 2
    }
    .CombineWithConditionalAnd();

var filteredOrders = orders.Where(extendedFilter.Compile());

Sort entities

Basic usage

Install NuGet packages

Package Manager : Install-Package Plainquire.Sort
CLI : dotnet add package Plainquire.Sort

Create a sort

using Plainquire.Sort;

var orders = new[] {
   new Order { Customer = "Joe Miller", Number = 100 },
   new Order { Customer = "Joe Smith", Number = 200 },
   new Order { Customer = "Joe Smith", Number = 300 },
};

// Create sort
var sort = new EntitySort<Order>()
    .Add(x => x.Customer, SortDirection.Ascending)
    .Add(x => x.Number, SortDirection.Descending);

// Print sort
Console.WriteLine($"{orders.OrderBy(sort)}");
// Output: orders.OrderBy(x => IIF((x == null), null, x.Customer)).ThenByDescending(x => x.Number)

// Use sort with LINQ
var sortedOrders = orders.OrderBy(sort).ToList();
// Or queryables (e.g. Entity Framework)
var sortedOrders = dbContext.Orders.OrderBy(sort).ToList();

[EntityFilter]
public class Order
{
   public int Number { get; set; }
   public string Customer { get; set; }
}

Or bind sort from query-parameters

using Plainquire.Sort;

[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] EntitySort<Order> sort)
{
    return dbContext.Orders.OrderBy(sort).ToList();
}

Add sorting

// Order is sorted by `Address` ascending.
var sort = new EntitySort<Order>();

// via operator
sort.Add(x => x.Address, SortDirection.Ascending);

// via syntax
sort.Add("Address-asc")

// via query parameter
var getOrdersUrl = "/GetOrders?orderBy=customer-asc"

Nested sorting

Nested objects are sorted directly (x=> x.OrderBy(order => order.Customer)). Deep property paths (e.g. order => order.Customer.Length) are supported. Methods calls (e.g. order => order.Customer.SubString(1)) are not supported for security reasons.

Nested lists cannot be sorted directly. You can create an own EntitySort for it and sort the nested list by.

// Create sort
var addressSort = new EntitySort<Address>()
    .Add(x => x.City);

// AddNested() is equivalent to adding the paths directly
var orderSort = new EntitySort<Order>()
    .AddNested(x => x.Address, addressSort);

// Is equivalent to AddNested() above
var orderSort = new EntitySort<Order>()
    .Add(x => x.Address.City, SortDirection.Ascending);

// Print sort
Console.WriteLine(orders.OrderBy(orderSort).ToString());
// Output:
// orders => orders.OrderBy(x => IIF((IIF((x == null), null, x.Address) == null), null, x.Address.City))

public class Order
{
    public int Number { get; set; }
    public string Customer { get; set; }
    public Address Address { get; set; }
}

public record Address(string Street, string City);

Retrieve syntax and sort direction

var orderSort = new EntitySort<Order>()
    .Add(x => x.Customer, SortDirection.Ascending);

// Retrive sort syntax
var syntax = orderSort.GetPropertySortSyntax(x => x.Customer);
// Output: Customer-asc

// Retrive sort direction
var direction = orderSort.GetPropertySortDirection(x => x.Customer);
// Output: Ascending

// Retrive sort expression string:
var orderExpression = orders.OrderBy(orderSort).ToString()

REST / MVC

To sort an entity via model binding, the entity must be marked with EntityFilterAttribute

Register model binders

Package Manager : Install-Package Plainquire.Sort.Mvc
CLI : dotnet add package Plainquire.Sort.Mvc

using Plainquire.Sort.Mvc;

// Register required stuff by calling 'AddSortSupport()' on IMvcBuilder instance
services.AddControllers().AddSortSupport();

Map HTTP query parameter to EntitySort

With model binding enabled, REST requests can be sorted using query parameter orderBy.

using Plainquire.Sort;

var getOrdersUrl = "/GetOrders?orderBy=customer,number-desc"

[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] EntitySort<Order> sort)
{
    var orders = new List<Order>();
    var sortedOrders = orders.OrderBy(sort);
    Console.WriteLine($"{sortedOrders.OrderBy(sort)}");
    // Output: orders.OrderBy(x => IIF((x == null), null, x.Customer)).ThenByDescending(x => x.Number)

    var queryParams = sort.ToString();
    // Output: Customer-asc, Number-desc
}

Configure model binding

By default, parameters for properties of sorted entity are named {Entity}{Property}. By default, all public non-complex properties (string, int, DateTime, ...) are recognized. Parameters can be renamed or removed using FilterAttribute and EntityFilterAttribute.

For the code below Number is not mapped anymore and Customer becomes CustomerName.

using Plainquire.Filter.Abstractions;

// Remove prefix, e.g. property 'Number' is mapped from 'number', not 'orderNumber'
// Use 'sortBy' as query parameter name instead of default 'orderBy'
[EntityFilter(Prefix = "")]
public class Order
{
     // 'Number' is removed from sort and will be ignored
    [Filter(Sortable = false)]
    public int Number { get; set; }

    // 'Customer' is mapped from query-parameter 'customerName'
    [Filter(Name = "CustomerName")]
    public string Customer { get; set; }
}

Order sets

Multiple entity sorts can be combined to a set of filters using the EntitySortSetAttribute.

using Plainquire.Sort;
using Plainquire.Sort.Abstractions;

// Use
[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] OrderSortSet orderSet)
{
    var orderSort = orderSet.Order;
    var orderItemSort = orderSet.OrderItem;
}

// Instead of
public Task<List<Order>> GetOrders([FromQuery] EntitySort<Order> orderSort, EntitySort<OrderItem> orderItemSort) { ... }

[EntitySortSet]
public class OrderSortSet
{
    public EntitySort<Order> Order { get; set; }
    public EntitySort<OrderItem> OrderItem { get; set; }
}

Swagger / OpenAPI

Register OpenAPI support

Swagger / OpenAPI is supported when using Swashbuckle.AspNetCore.

Package Manager : Install-Package Plainquire.Sort.Swashbuckle
CLI : dotnet add package Plainquire.Sort.Swashbuckle

using Plainquire.Sort.Swashbuckle;

services.AddSwaggerGen(options =>
{
    // Register filters used to modify swagger.json
    options.AddSortSupport();
});

Support for Newtonsoft.Json

By default, System.Text.Json is used to serialize/convert Plainquire specific stuff. If you like to use Newtonsoft.Json you must register it.

Package Manager : Install-Package Plainquire.Sort.Mvc.Newtonsoft
CLI : dotnet add package Plainquire.Sort.Mvc.Newtonsoft

using Plainquire.Sort.Mvc.Newtonsoft;

// Register support for Newtonsoft by calling
// 'AddSortNewtonsoftSupport()' on IMvcBuilder instance
services.AddControllers().AddSortNewtonsoftSupport();

Configuration

Creation of sort expression can be configured via SortConfiguration.

using Plainquire.Sort.Abstractions;

var configuration = new SortConfiguration();
configuration.AscendingPostfixes.Add("^");
var sort = new EntitySort<Order>(configuration);
var sortedOrders = orders.OrderBy(sort);

The configuration can be provided as follows and is used according to the listed order of precedence

// For MVC model binding via dependency injection
services.Configure<SortConfiguration>(c => c.IgnoreParseExceptions = true);

// Via constructor
new EntitySort<Order>(configuration);

// Via static default
SortConfiguration.Default

Interception

Creation of sort expression can be intercepted via ISortInterceptor.

var sort = new EntitySort<Order>();
var interceptor = new CaseInsensitiveSortInterceptor();
var filtered = orders.OrderBy(sort, interceptor);

A default interceptor can be provided via static ISortInterceptor.Default.

Advanced scenarios

Deep copy

The EntitySort<T> class supports deep cloning by calling the Clone() method

var copy = sort.Clone();

Casting

Sorting can be cast between entities, e.g. to convert them between DTOs and database models.

Properties are matched by type (check if assignable) and name (case-sensitive)

var dtoSort = new EntitySort<OrderDto>().Add(...);
var orderSort = dtoSort.Cast<Order>();

Serialization

Using System.Text.Json

Objects of type EntitySort<T> can be serialized via System.Text.Json.JsonSerializer without further requirements

var json = JsonSerializer.Serialize(sort);
sort = JsonSerializer.Deserialize<EntitySort<Order>>(json);

Using Newtonsoft.Json

When using Newtonsoft.Json additional converters are required

Package Manager : Install-Package Plainquire.Sort.Newtonsoft
CLI : dotnet add package Plainquire.Sort.Newtonsoft

using Plainquire.Sort.Newtonsoft;

var json = JsonConvert.SerializeObject(sort, JsonConverterExtensions.NewtonsoftConverters);
sort = JsonConvert.DeserializeObject<EntitySort<Order>>(json, JsonConverterExtensions.NewtonsoftConverters);

Page Entities

Basic usage

Install NuGet packages

Package Manager : Install-Package Plainquire.Page
CLI : dotnet add package Plainquire.Page

Create a page

using Plainquire.Page;

// Direct pageing is the preferred way
var pagedOrders = orders.Page(pageNumber: 2, pageSize: 3).ToList();

// Alternative, create a EntityPage object
var page = new EntityPage(pageNumber: 2, pageSize: 3);

// Use page with LINQ
var pagedOrders = orders.Page(page).ToList();
// Or queryables (e.g. Entity Framework)
var pagedOrders = dbContext.Orders.Page(page).ToList();

REST / MVC

To page an entity via model binding, the entity must be marked with EntityFilterAttribute

Register model binders

Package Manager : Install-Package Plainquire.Page.Mvc
CLI : dotnet add package Plainquire.Page.Mvc

using Plainquire.Page.Mvc;

// Register required stuff by calling 'AddPageSupport()' on IMvcBuilder instance
services.AddControllers().AddPageSupport();

Map HTTP query parameter to EntityPage

With model binding enabled, REST requests can be paged using query parameters page and pageSize.

using Plainquire.Page;

var getOrdersUrl = "/GetOrders?page=2&pageSize=3"

[HttpGet]
public Task<List<Order>> GetOrders([FromQuery] EntityPage<Order> page)
{
    return dbContext.Orders.Page(page).ToList();
}

Configure model binding

Parameters can be renamed EntityFilterAttribute.

For the code below page number is taken from query parameter pageNumber and page size from size.

using Plainquire.Filter.Abstractions;

[EntityFilter(PageNumberParameter = "pageNumber", PageSizeParameter = "size")]
public class Order
{
    public string Customer { get; set; }
}

Swagger / OpenAPI

Register OpenAPI support

Swagger / OpenAPI is supported when using Swashbuckle.AspNetCore.

Package Manager : Install-Package Plainquire.Page.Swashbuckle
CLI : dotnet add package Plainquire.Page.Swashbuckle

using Plainquire.Page.Swashbuckle;

services.AddSwaggerGen(options =>
{
    // Register filters used to modify swagger.json
    options.AddPageSupport();
});

Support for Newtonsoft.Json

By default, System.Text.Json is used to serialize/convert Plainquire specific stuff. If you like to use Newtonsoft.Json you must register it.

Package Manager : Install-Package Plainquire.Page.Mvc.Newtonsoft
CLI : dotnet add package Plainquire.Page.Mvc.Newtonsoft

using Plainquire.Page.Mvc.Newtonsoft;

// Register support for Newtonsoft by calling
// 'AddPageNewtonsoftSupport()' on IMvcBuilder instance
services.AddControllers().AddPageNewtonsoftSupport();

Configuration

Creation of page expression can be configured via PageConfiguration.

using Plainquire.Page.Abstractions;

var configuration = new PageConfiguration() { IgnoreParseExceptions = true };
var page = new EntityPage<Order>(configuration);
var pagedOrders = orders.Page(page);

The configuration can be provided as follows and is used according to the listed order of precedence

// For MVC model binding via dependency injection
services.Configure<PageConfiguration>(c => c.IgnoreParseExceptions = true);

// Via constructor
new EntityPage<Order>(configuration);

// Via static default
PageConfiguration.Default

Interception

Creation of page expression can be intercepted via IPageInterceptor.

var page = new EntityPage();
var interceptor = new PageBackwardInterceptor();
var paged = orders.Page(page, interceptor);

A default interceptor can be provided via static IPageInterceptor.Default.

Advanced Scenarios

Deep copy

The EntityPage<T> class supports deep cloning by calling the Clone() method

var copy = page.Clone();

Serialization

Using System.Text.Json

Objects of type EntityPage<T> can be serialized via System.Text.Json.JsonSerializer without further requirements

var json = JsonSerializer.Serialize(page);
page = JsonSerializer.Deserialize<EntityPage<Order>>(json);

Using Newtonsoft.Json

When using Newtonsoft.Json additional converters are required

Package Manager : Install-Package Plainquire.Page.Newtonsoft
CLI : dotnet add package Plainquire.Page.Newtonsoft

using Plainquire.Page.Newtonsoft;

var json = JsonConvert.SerializeObject(page, JsonConverterExtensions.NewtonsoftConverters);
sort = JsonConvert.DeserializeObject<EntityPage<Order>>(json, JsonConverterExtensions.NewtonsoftConverters);

Upgrade from FilterExpressionCreator

• Install Schick.FilterExpressionCreator* 4.7.x.

• Fix all warnings. This can largely be done by sear and replacing with regular expressions

  • Search for: FS.FilterExpressionCreator(\.Abstractions|Mvc|Mvc\.Newtonsoft|Newtonsoft)?(\.\w+)?
  • Replace with: Plainquire.Filter$1
  • Search for: \[FilterEntity(\(.*\))]
  • Replace with: [EntityFilter$1]

• Fix remaining errors and warnings following description of breaking changes

• Uninstall all Schick.FilterExpressionCreator* stuff

• Install corresponding Plainquire.* packages