MudDataGrid: Add extensions method on IQueryable for easy filtering and ordering

[0xced]

Description

This pull request introduces two new extensions methods on IQueryable: Where that takes a IEnumerable<IFilterDefinition<T>> and OrderBy that takes a IEnumerable<SortDefinition<T>>.

This enables a straightforward implementations of the ServerData function, for example with EF Core.

using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;

namespace MudBlazor;

internal static class QueryGridExtensions
{
    public static async Task<GridData<T>> LoadServerDataAsync<T>(this IQueryable<T> source, GridState<T> state, CancellationToken cancellationToken = default)
    {
        var query = source.Where(state.FilterDefinitions).OrderBy(state.SortDefinitions);
        var items = await query.Skip(state.Page * state.PageSize).Take(state.PageSize).ToListAsync(cancellationToken);
        var totalItems = await query.CountAsync(cancellationToken);
        return new GridData<T> { Items = items, TotalItems = totalItems };
    }
}

(A good implementation would need to order the source with a default ordering in case the sort definitions are empty.)

It also fixes #6682.

How Has This Been Tested?

Two new unit tests have been added: QueryFilterExtensionTest and QuerySortExtensionTest.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• The PR is submitted to the correct branch (dev).
• My code follows the code style of this project.
• I've added relevant tests.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.99%. Comparing base (345ec7c) to head (2c675f1).

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #8254      +/-   ##
==========================================
+ Coverage   88.82%   88.99%   +0.17%     
==========================================
  Files         407      409       +2     
  Lines       12226    12252      +26     
  Branches     2441     2447       +6     
==========================================
+ Hits        10860    10904      +44     
+ Misses        834      819      -15     
+ Partials      532      529       -3     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[vernou]

Maybe NRT can be enable on this file? Like you did in QuerySortExtensions.cs.

[0xced]

Good point! I did in in f60b021, rebased on the dev branch and force-pushed.

[Militancy]

Hey @0xced,

thanks for your pull request, I currently struggled to find a way to do those queries user friendly. For myself I would like that extension to be a bit more powerful.

Would you consider to implement an solution where its possible to query for included class structures, like for example extend the MemberExpression for each member of depth?

[vernou]

@Militancy

Would you consider to implement an solution where its possible to query for included class structures, like for example extend the MemberExpression for each member of depth?

I am not sure I understand...
Have you a example?
Will the resulting expressions be EF compatible?

[Militancy]

@vernou
In a specific example we have two classes, where we want to query for a value of a nested class. As i tested your stuff i noticed that the the extension for filtering was already working for nested class properties. Only on the sorting part a adjustment was necessary.

I tested it with my own class structures with EF on SQLite successfully.

Example Column for MudDataGrid
<PropertyColumn Property="p => p.B.Name"/>

Class example

public class A {
    public int BId { get; set; }
    public B { get; set; }
}

public class B {
    public string Name { get; set; }
}

A "solution" would be sth like this. But I dont know if its the best way to go.

MemberExpression propertyExpression;
if(sortDefinition.SortBy.Contains('.'))
{
    var properties = sortDefinition.SortBy.Split('.');
    propertyExpression = Expression.Property(parameter, properties.First());
    foreach(var prop in properties.Skip(1))
        propertyExpression = Expression.Property(propertyExpression, prop);
}
else
    propertyExpression = Expression.Property(parameter, sortDefinition.SortBy);

[ScarletKuro]

Hi, thanks for the PR.

@mikes-gh I think it's very problematic for us that this is not trim compatible because of this line

MudBlazor/src/MudBlazor/Components/DataGrid/QuerySortExtensions.cs

Line 43 in 407e00c

var propertyExpression = Expression.Property(parameter, sortDefinition.SortBy);

if SortDefinition contained the type information of the property it would be, since there is an overload that accepts type info.
Honestly, I'm not sure what to do with this PR, tho I like the idea.

I will @tjscience let to decide.

[0xced]

@Militancy I think I figured out a way to support your scenario. Instead of adding one extension method, I added two extension methods (and force pushed my branch). The new one that I added takes an additional Func<ParameterExpression, SortDefinition<T>, Expression> that lets you define the expression as you see fit for the given sort definition. The default implementation for the standard case does Expression.Property(parameter, sortDefinition.SortBy) but now you can write your own if that's not enough.

@ScarletKuro I don't think that's a problem since the type T is user supplied and thus very unlikely to be trimmed.