QueryEngine<T0>.SetDefaultFilter

Parameters

Description

Sets the default filter handler for filters that were not registered.

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

static class Example_QueryEngine_SetDefaultFilter
{
    static List<MyObjectType> s_Data;

    [MenuItem("Examples/QueryEngine/SetDefaultFilter")]
    public static void RunExample()
    {
        // Set up the query engine
        var queryEngine = new QueryEngine<MyObjectType>();
        queryEngine.SetSearchDataCallback(myObj => new[] { myObj.id.ToString(), myObj.name });

        // Add a filter for MyObjectType.id that supports all operators
        queryEngine.AddFilter("id", myObj => myObj.id);

        // For all other filters, you can register a "default" filter handler that will be called when
        // an unknown filter token is encountered. It can also be useful for dynamic properties.
        queryEngine.SetDefaultFilter((myObj, filterId, operatorToken, filterValue) =>
        {
            if (myObj.property.name != filterId)
                return false;

            if (myObj.property.type == PropertyType.String)
            {
                if (!(myObj.property.value is string s))
                    return false;
                switch (operatorToken)
                {
                    case ":": return s.Contains(filterValue);
                    case "=": return s == filterValue;
                    default: return false;
                }
            }

            if (myObj.property.type == PropertyType.Integer)
            {
                if (!(myObj.property.value is int i))
                    return false;
                if (!int.TryParse(filterValue, out var filterValueInt))
                    return false;
                switch (operatorToken)
                {
                    case "=": return i == filterValueInt;
                    case "!=": return i != filterValueInt;
                    case "<": return i < filterValueInt;
                    case ">": return i > filterValueInt;
                    case "<=": return i <= filterValueInt;
                    case ">=": return i >= filterValueInt;
                    default: return false;
                }
            }

            return false;
        });

        s_Data = new List<MyObjectType>()
        {
            new MyObjectType { id = 0, property = new Property("size", PropertyType.Integer, 64) },
            new MyObjectType { id = 1, property = new Property("size", PropertyType.Integer, 128) },
            new MyObjectType { id = 2, property = new Property("tag", PropertyType.String, "item") },
            new MyObjectType { id = 3, property = new Property("tag", PropertyType.String, "car item") }
        };

        // Find all items that have the property "size" that is equal to 64
        var query = queryEngine.Parse("size=64");
        var filteredData = query.Apply(s_Data).ToList();
        Debug.Assert(filteredData.Count == 1, $"There should be 1 item in the filtered list but found {filteredData.Count} items.");
        Debug.Assert(filteredData.Contains(s_Data[0]), "The first item should be in the filtered list since its property \"size\" has a value of 64.");

        // Find all items that have the property "tag" that contains "item"
        query = queryEngine.Parse("tag:item");
        filteredData = query.Apply(s_Data).ToList();
        Debug.Assert(filteredData.Count == 2, $"There should be 2 item in the filtered list but found {filteredData.Count} items.");
        Debug.Assert(filteredData.Contains(s_Data[2]), "The third item should be in the list as its property \"tag\" contains \"item\".");
        Debug.Assert(filteredData.Contains(s_Data[3]), "The fourth item should be in the list as its property \"tag\" contains \"item\".");
    }

    enum PropertyType
    {
        Integer,
        String
    }
    struct Property
    {
        public string name { get; }
        public PropertyType type { get; }
        public object value { get; set; }

        public Property(string name, PropertyType type, object value)
        {
            this.name = name;
            this.type = type;
            this.value = value;
        }
    }

    class MyObjectType
    {
        public int id { get; set; }
        public string name { get; set; } = string.Empty;
        public Vector2 position { get; set; } = Vector2.zero;
        public bool active { get; set; }
        public Property property { get; set; }

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