LightQuery

Online Documentation

This project aims to provide a lightweight ActionFilterAttribute that takes care of sorting and paginating Asp.Net Core API results.

This project is for you if you're still waiting for OData support in Asp.Net Core, even though you only need the most basic of operations. It's also for everyone tired of writing like the 17th string sort = "Username" parameter and lines over lines of switch statements in their controller actions.

It supports EntityFrameworkCores async query materialization with the optional LightQuery.EntityFrameworkCore package.

In addition to the C# client, there's also a client for Angular 5+ on npm: ng-lightquery

Installation

The package is available on nuget. Daily builds are on myget.

MyGet feed: https://www.myget.org/F/dangl/api/v3/index.json

PM> Install-Package LightQuery

Includes the core functionality to sort and paginate Asp.Net Core controller results

PM> Install-Package LightQuery.EntityFrameworkCore

Includes support for EntityFramework.Core async query materialization

PM> Install-Package LightQuery.Client

Includes LightQuery models and the QueryBuilder utility

Both NETStandard 1.6 and .Net 4.6.1 are supported.

Documentation - Server

See below how to apply sorting & filtering to your API controllers. At a glance:

• Return an ObjectResult from your controller with an IQueryable value
• Use sort to sort, page & pageSize for pagination in your requests

You can find a demo in the integration test projects for an example of using this in an Asp.Net Core MVC application for sorting and filtering.

Sorting

using LightQuery;

public class ApiController : Controller
{
    [LightQuery]
    [ProducesResponseType(typeof(IEnumerable<User>), 200)]
    public IActionResult GetValues()
    {
        var values = _repository.GetAllValuesAsQueryable();
        return Ok(values);  
    }
}

Annotate your controller actions with the LightQueryAttribute and it takes care of applying url queries to the result. All ObjectResults (docs) that have an IQueryable value will be transformed. You're free to return any other results, too, from the annotated action and it will simply be ignored.

Example: http://your.api.com/values?sort=email desc

This will sort the result by its Email property (it is title-cased if no email property is found) in descending order.

Pagination & Sorting

Paging is active when the request includes pagination query parameters or via explicitly setting the forcePagination parameter to true in the attributes' constructor. Sorting works in combination with paging.

using LightQuery;

public class ApiController : Controller
{
    [LightQuery(forcePagination: true, defaultPageSize: 3)]
    [ProducesResponseType(typeof(PaginationResult<User>), 200)]
    public IActionResult GetValues()
    {
        var values = _repository.GetAllValuesAsQueryable();
        return Ok(values);  
    }
}

Example: http://your.api.com/values?sort=email&page=2&pageSize=3

Response

{
    "page": 2,
    "pageSize": 3,
    "totalCount": 20,
    "data": [
        { "userName": "Dave", "email": "[email protected]" },
        { "userName": "Emilia", "email": "[email protected]" },
        { "userName": "Fred", "email": "[email protected]" }
    ]
}

Async Materialization

The LightQuery.EntityFrameworkCore package provides an AsyncLightQueryAttribute. This can be used for data sources that support async materialization of queries, e.g. var result = await context.Users.ToListAsync().

Documentation - C# Client

The LightQuery.Client package contains the PaginationResult<T> base class as well as a QueryBuilder utlity class to construct queries.

Example

using LightQuery.Client;

var url = QueryBuilder.Build(page: 3, pageSize: 25, sortParam: "email");
var response = await _client.GetAsync(url);
var responseContent = await response.Content.ReadAsStringAsync();
var deserializedResponse = JsonConvert.DeserializeObject<PaginationResult<User>>(responseContent);

PaginationBaseService

The LightQuery.Client package contains an abstract class PaginationBaseService<T> that can be used in reactive clients. It is similar in functionality to the TypeScript client.

Documentation - TypeScript & Angular

There is an Angular example that can be used standalone or in combination with a @angular/material2 DataTable and its pagination and sort functionality.

Example with Material 2 DataTable

<md-table [dataSource]="dataSource"
          mdSort
          [mdSortActive]="usersService.sort?.propertyName"
          [mdSortDirection]="usersService.sort?.isDescending ? 'desc' : 'asc'"
          (mdSortChange)="onSort($event)">
    <ng-container cdkColumnDef="email">
        <md-header-cell md-sort-header *cdkHeaderCellDef> Email </md-header-cell>
        <md-cell *cdkCellDef="let row">
            {{row.email}}
        </md-cell>
    </ng-container>
    <md-header-row *cdkHeaderRowDef="['email']"></md-header-row>
    <md-row *cdkRowDef="let row; columns: ['email'];"></md-row>
</md-table>
<md-paginator [length]="usersPaginated.totalCount"
              [pageSize]="usersPaginated.pageSize"
              [pageIndex]="usersPaginated.page - 1"
              (page)="onPage($event)">
</md-paginator>

export class UsersComponent implements OnInit, OnDestroy {

    constructor(public userService: UserService) { }

    private usersPaginatedSubscription: Subscription;
    usersPaginated: PaginationResult<User>;
    dataSource: DataSource<User>;

    onPage(pageEvent: PageEvent) {
        this.userService.page = pageEvent.pageIndex + 1;
        this.userService.pageSize = pageEvent.pageSize;
    }

    onSort(event: { active: string, direction: string }) {
        if (!event.direction) {
            this.userService.sort = null;
        } else {
            this.userService.sort = { propertyName: event.active, isDescending: event.direction === 'desc' };
        }
    }

    ngOnInit() {
        this.dataSource = this.userService;
        this.usersPaginatedSubscription = this.userService.paginationResult.subscribe(r => this.usersPaginated = r);
    }

    ngOnDestroy() {
        this.usersPaginatedSubscription.unsubscribe();
    }
}

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MIT License