IQueryEngineFilter

描述

面向 QueryEngine 过滤器的界面。

在 QueryEngine 中添加新的过滤器后，您会收到一个实现界面 IQueryEngineFilter 的过滤器对象。您可以修改此过滤器来覆盖 QueryEngine 的全局行为。例如，您可以添加针对此过滤器特定的 类型解析器 或 操作符。

using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using UnityEditor;
using UnityEditor.Search;
using UnityEngine;

static class Example_IQueryEngineFilter
{
    static List<MyObjectType> s_Data;

    static QueryEngine<MyObjectType> SetupQueryEngine()
    {
        // Set up the query engine
        var queryEngine = new QueryEngine<MyObjectType>();

        // Add a filter for MyObjectType.position that supports equals and not equals
        queryEngine.AddFilter("p", myObj => myObj.position, new[] { "=", "!=" });

        // Add a new type parser for Vector2 written as "[x, y]", but only for this filter.
        // This type parser will not affect other filters.
        queryEngine.TryGetFilter("p", out var filter);
        filter.AddTypeParser(s =>
        {
            // If the format requirement is not met, return a failure.
            if (!s.StartsWith("[") || !s.EndsWith("]"))
                return ParseResult<Vector2>.none;

            var trimmed = s.Trim('[', ']');
            var vectorTokens = trimmed.Split(',');
            var vectorValues = vectorTokens.Select(token => float.Parse(token, CultureInfo.InvariantCulture.NumberFormat)).ToList();
            if (vectorValues.Count != 2)
                return ParseResult<Vector2>.none;
            var vector = new Vector2(vectorValues[0], vectorValues[1]);

            // When the conversion succeeds, return a success.
            return new ParseResult<Vector2>(true, vector);
        });

        // Override global operators with specific operator handlers for this filter
        filter.AddOperator("=").AddHandler((Vector2 ev, Vector2 fv) => ev == fv);
        filter.AddOperator("!=").AddHandler((Vector2 ev, Vector2 fv) => ev != fv);

        // Set up what data from objects of type MyObjectType will be matched against search words
        queryEngine.SetSearchDataCallback(myObj => new[] { myObj.id.ToString(), myObj.name });

        return queryEngine;
    }

    [MenuItem("Examples/IQueryEngineFilter/IQueryEngineFilter")]
    public static void RunExample()
    {
        s_Data = GenerateExampleData();
        var queryEngine = SetupQueryEngine();
        TestFiltering(queryEngine, s_Data);
    }

    static void TestFiltering(QueryEngine<MyObjectType> queryEngine, IEnumerable<MyObjectType> inputData)
    {
        var vec = new Vector2(1, 0);
        // Find objects that are at position [1, 0]
        var filteredData = FilterData("p=[1,0]", queryEngine, inputData);
        ValidateData(filteredData, s_Data.Where(myObj => myObj.position == vec));

        //Find objects that are not at position [1, 0]
        filteredData = FilterData("p!=[1,0]", queryEngine, inputData);
        ValidateData(filteredData, s_Data.Where(myObj => myObj.position != vec));
    }

    static IEnumerable<MyObjectType> FilterData(string inputQuery, QueryEngine<MyObjectType> queryEngine, IEnumerable<MyObjectType> inputData)
    {
        // Parse the query string into a query operation
        var query = queryEngine.ParseQuery(inputQuery);

        // If the query is not valid, print all errors and return an empty data set
        if (!query.valid)
        {
            foreach (var queryError in query.errors)
            {
                Debug.LogFormat(LogType.Error, LogOption.NoStacktrace, null, $"Error parsing input at {queryError.index}: {queryError.reason}");
            }

            return new List<MyObjectType>();
        }

        // Apply the query on a data set and get the filtered result.
        var filteredData = query.Apply(inputData);
        return filteredData;
    }

    static void ValidateData(IEnumerable<MyObjectType> filteredData, IEnumerable<MyObjectType> expectedData)
    {
        var filteredDataArray = filteredData.ToArray();
        var expectedDataArray = expectedData.ToArray();
        Debug.Assert(filteredDataArray.Length == expectedDataArray.Length, $"Filtered data should have {expectedDataArray.Length} elements.");
        if (filteredDataArray.Length != expectedDataArray.Length)
            return;

        for (var i = 0; i < expectedDataArray.Length; i++)
        {
            Debug.Assert(filteredDataArray[i] == expectedDataArray[i], $"{filteredDataArray[i]} should be equal to {expectedDataArray[i]}");
        }
    }

    static List<MyObjectType> GenerateExampleData()
    {
        var data = new List<MyObjectType>()
        {
            new MyObjectType { id = 0, name = "Test 1", position = new Vector2(0, 0), active = false },
            new MyObjectType { id = 1, name = "Test 2", position = new Vector2(0, 1), active = true },
            new MyObjectType { id = 2, name = "Test 3", position = new Vector2(1, 0), active = false },
            new MyObjectType { id = 3, name = "Test 4", position = new Vector2(1.2f, 0), active = false },
        };

        return data;
    }

    /// <summary>
    /// Custom type. This is the type of objects that will be searched by the QueryEngine.
    /// </summary>
    class MyObjectType
    {
        public int id { get; set; }
        public string name { get; set; }
        public Vector2 position { get; set; }
        public bool active { get; set; }

        public MyObjectType()
        {
            id = 0;
            name = "";
            position = Vector2.zero;
            active = false;
        }

        public override string ToString()
        {
            return $"({id}, {name}, ({position.x}, {position.y}), {active})";
        }
    }
}

属性

公有方法