merged main

Author: Jamess-Lucass

src/Extensions/QueryableExtension.cs

@@ -0,0 +1,133 @@
+using System.Linq.Dynamic.Core;
+using System.Reflection;
+using System.Text;
+using System.Text.Json.Serialization;
+
+public static class QueryableExtension
+{
+    public static Dictionary<string, string> _filterOperations => new Dictionary<string, string>
+    {
+        {"eq", "=="},
+        {"ne", "!="},
+        {"contains", "Contains"},
+    };
+
+    public static (IQueryable, int?) Apply<T>(this IQueryable<T> queryable, Query query, int? maxTop = null, ISearchBinder<T>? searchBinder = null)
+    {
+        var result = (IQueryable)queryable;
+
+        if (maxTop is not null && query.Top > maxTop)
+        {
+            throw new GoatQueryException("The value supplied for the query parameter 'Top' was greater than the maximum top allowed for this resource");
+        }
+
+        // Filter
+        if (!string.IsNullOrEmpty(query.Filter))
+        {
+            var filters = StringHelper.SplitString(query.Filter);
+
+            var where = new StringBuilder();
+
+            for (int i = 0; i < filters.Count; i++)
+            {
+                var filter = filters[i];
+                var opts = StringHelper.SplitStringByWhitespace(filter.Trim());
+
+                if (opts.Count != 3)
+                {
+                    continue;
+                }
+
+                if (i > 0)
+                {
+                    var prev = filters[i - 1];
+                    where.Append($" {prev.Trim()} ");
+                }
+
+                var property = opts[0].Replace("\'", string.Empty);
+                var operand = opts[1];
+                var value = opts[2].Replace("'", "\"");
+
+                string? propertyName = typeof(T).GetProperties().FirstOrDefault(x => x.GetCustomAttribute<JsonPropertyNameAttribute>()?.Name == property)?.Name;
+
+                if (!string.IsNullOrEmpty(propertyName))
+                {
+                    property = propertyName;
+                }
+
+                if (typeof(T).GetProperties().FirstOrDefault(x => x.Name.Equals(property, StringComparison.OrdinalIgnoreCase))?.PropertyType == typeof(string))
+                {
+                    if (operand.Equals("contains", StringComparison.OrdinalIgnoreCase))
+                    {
+                        where.Append($"{property}.ToLower().Contains({value}.ToLower())");
+                    }
+                    else
+                    {
+                        where.Append($"{property}.ToLower() {_filterOperations[operand]} {value}.ToLower()");
+                    }
+                }
+                else if (operand.Equals("contains", StringComparison.OrdinalIgnoreCase))
+                {
+                    where.Append($"{property}.{_filterOperations[operand]}({value})");
+                }
+                else if (typeof(T).GetProperties().FirstOrDefault(x => x.Name.Equals(property, StringComparison.OrdinalIgnoreCase))?.PropertyType == typeof(Guid))
+                {
+                    where.Append($"{property} {_filterOperations[operand]} Guid({value})");
+                }
+                else
+                {
+                    where.Append($"{property} {_filterOperations[operand]} {value}");
+                }
+            }
+
+            result = result.Where(where.ToString());
+        }
+
+        // Search
+        if (searchBinder is not null && !string.IsNullOrEmpty(query.Search))
+        {
+            var searchExpression = searchBinder.Bind(query.Search);
+
+            if (searchExpression is null)
+            {
+                throw new GoatQueryException("search binder does not return valid expression that can be parsed to where clause");
+            }
+
+            result = result.Where(searchExpression);
+        }
+
+        int? count = null;
+
+        // Count
+        if (query.Count ?? false)
+        {
+            count = result.Count();
+        }
+
+        // Order by
+        if (!string.IsNullOrEmpty(query.OrderBy))
+        {
+            result = result.OrderBy(query.OrderBy);
+        }
+
+        // Select
+        if (!string.IsNullOrEmpty(query.Select))
+        {
+            result = result.Select($"new {{ {query.Select} }}");
+        }
+
+        // Skip
+        if (query.Skip > 0)
+        {
+            result = result.Skip(query.Skip ?? 0);
+        }
+
+        // Top
+        if (query.Top > 0)
+        {
+            result = result.Take(query.Top ?? 0);
+        }
+
+        return (result, count);
+    }
+}