| | | 1 | | using Fluorite.Strainer.Models.Metadata; |
| | | 2 | | using Fluorite.Strainer.Models.Sorting; |
| | | 3 | | using Fluorite.Strainer.Models.Sorting.Terms; |
| | | 4 | | using Fluorite.Strainer.Services.Metadata; |
| | | 5 | | using System.Linq.Expressions; |
| | | 6 | | |
| | | 7 | | namespace Fluorite.Strainer.Services.Sorting; |
| | | 8 | | |
| | | 9 | | /// <summary> |
| | | 10 | | /// Provides means of tranlating <see cref="ISortTerm"/> into |
| | | 11 | | /// <see cref="Expression{TDelegate}"/> of <see cref="Func{T, TResult}"/>. |
| | | 12 | | /// <para/> |
| | | 13 | | /// In other words - provides list of expressions which later can be used |
| | | 14 | | /// as arguments for ordering <see cref="IQueryable{T}"/>. |
| | | 15 | | /// </summary> |
| | | 16 | | public class SortExpressionProvider : ISortExpressionProvider |
| | | 17 | | { |
| | | 18 | | private readonly IMetadataFacade _metadataProvidersFacade; |
| | | 19 | | private readonly IStrainerOptionsProvider _strainerOptionsProvider; |
| | | 20 | | |
| | | 21 | | /// <summary> |
| | | 22 | | /// Initializes a new instance of the <see cref="SortExpressionProvider"/> class. |
| | | 23 | | /// </summary> |
| | 7 | 24 | | public SortExpressionProvider( |
| | 7 | 25 | | IMetadataFacade metadataProvidersFacade, |
| | 7 | 26 | | IStrainerOptionsProvider strainerOptionsProvider) |
| | | 27 | | { |
| | 7 | 28 | | _metadataProvidersFacade = Guard.Against.Null(metadataProvidersFacade); |
| | 7 | 29 | | _strainerOptionsProvider = Guard.Against.Null(strainerOptionsProvider); |
| | 7 | 30 | | } |
| | | 31 | | |
| | | 32 | | /// <inheritdoc/> |
| | | 33 | | public ISortExpression<TEntity>? GetDefaultExpression<TEntity>() |
| | | 34 | | { |
| | 3 | 35 | | var propertyMetadata = _metadataProvidersFacade.GetDefaultMetadata<TEntity>(); |
| | 3 | 36 | | if (propertyMetadata is null) |
| | | 37 | | { |
| | 1 | 38 | | return null; |
| | | 39 | | } |
| | | 40 | | |
| | 2 | 41 | | var name = propertyMetadata.DisplayName ?? propertyMetadata.Name; |
| | 2 | 42 | | var defaultSortingWay = propertyMetadata.DefaultSortingWay |
| | 2 | 43 | | ?? _strainerOptionsProvider.GetStrainerOptions().DefaultSortingWay; |
| | 2 | 44 | | var isDescending = defaultSortingWay == SortingWay.Descending; |
| | 2 | 45 | | var sortTerm = new SortTerm(name) |
| | 2 | 46 | | { |
| | 2 | 47 | | IsDescending = isDescending, |
| | 2 | 48 | | }; |
| | | 49 | | |
| | 2 | 50 | | return GetExpression<TEntity>(propertyMetadata, sortTerm, isSubsequent: false); |
| | | 51 | | } |
| | | 52 | | |
| | | 53 | | /// <inheritdoc/> |
| | | 54 | | /// <exception cref="ArgumentNullException"> |
| | | 55 | | /// <paramref name="propertyMetadata"/> is <see langword="null"/>. |
| | | 56 | | /// <paramref name="sortTerm"/> is <see langword="null"/>. |
| | | 57 | | /// </exception> |
| | | 58 | | public ISortExpression<TEntity> GetExpression<TEntity>( |
| | | 59 | | IPropertyMetadata propertyMetadata, |
| | | 60 | | ISortTerm sortTerm, |
| | | 61 | | bool isSubsequent) |
| | | 62 | | { |
| | 6 | 63 | | Guard.Against.Null(propertyMetadata); |
| | 6 | 64 | | Guard.Against.Null(sortTerm); |
| | | 65 | | |
| | 6 | 66 | | var parameter = Expression.Parameter(typeof(TEntity), "p"); |
| | 6 | 67 | | Expression propertyValue = parameter; |
| | | 68 | | |
| | 6 | 69 | | if (propertyMetadata.Name.Contains(".")) |
| | | 70 | | { |
| | 1 | 71 | | var parts = propertyMetadata.Name.Split('.'); |
| | | 72 | | |
| | 4 | 73 | | for (var i = 0; i < parts.Length - 1; i++) |
| | | 74 | | { |
| | 1 | 75 | | propertyValue = Expression.PropertyOrField(propertyValue, parts[i]); |
| | | 76 | | } |
| | | 77 | | } |
| | | 78 | | |
| | 6 | 79 | | var propertyAccess = Expression.MakeMemberAccess(propertyValue, propertyMetadata.PropertyInfo!); |
| | 6 | 80 | | var conversion = Expression.Convert(propertyAccess, typeof(object)); |
| | 6 | 81 | | var orderExpression = Expression.Lambda<Func<TEntity, object>>(conversion, parameter); |
| | | 82 | | |
| | 6 | 83 | | return new SortExpression<TEntity>(orderExpression) |
| | 6 | 84 | | { |
| | 6 | 85 | | IsDefault = propertyMetadata.IsDefaultSorting, |
| | 6 | 86 | | IsDescending = sortTerm.IsDescending, |
| | 6 | 87 | | IsSubsequent = isSubsequent, |
| | 6 | 88 | | }; |
| | | 89 | | } |
| | | 90 | | |
| | | 91 | | /// <inheritdoc/> |
| | | 92 | | /// <exception cref="ArgumentNullException"> |
| | | 93 | | /// <paramref name="sortTerms"/> is <see langword="null"/>. |
| | | 94 | | /// </exception> |
| | | 95 | | public IReadOnlyList<ISortExpression<TEntity>> GetExpressions<TEntity>( |
| | | 96 | | IEnumerable<KeyValuePair<IPropertyMetadata, ISortTerm>> sortTerms) |
| | | 97 | | { |
| | 3 | 98 | | Guard.Against.Null(sortTerms); |
| | | 99 | | |
| | 3 | 100 | | var expressions = new List<ISortExpression<TEntity>>(); |
| | 3 | 101 | | var isSubqequent = false; |
| | | 102 | | |
| | 14 | 103 | | foreach (var pair in sortTerms) |
| | | 104 | | { |
| | 4 | 105 | | var sortExpression = GetExpression<TEntity>(pair.Key, pair.Value, isSubqequent); |
| | 4 | 106 | | if (sortExpression != null) |
| | | 107 | | { |
| | 4 | 108 | | expressions.Add(sortExpression); |
| | | 109 | | } |
| | | 110 | | else |
| | | 111 | | { |
| | | 112 | | continue; |
| | | 113 | | } |
| | | 114 | | |
| | 4 | 115 | | isSubqequent = true; |
| | | 116 | | } |
| | | 117 | | |
| | 3 | 118 | | return expressions.AsReadOnly(); |
| | | 119 | | } |
| | | 120 | | } |