私は2つの答えを見たことがなかったので、先に進んで独自の実装を行いました:
using System.Collections.Generic;
using System.Text.RegularExpressions;
namespace StringInterpolation {
/// <summary>
/// An object with an explicit, available-at-runtime name.
/// </summary>
public struct NamedObject {
public string Name;
public object Object;
public NamedObject(string name, object obj) {
Name = name;
Object = obj;
}
}
public static class StringInterpolation {
/// <summary>
/// Parses a string for basic Razor-like interpolation with explicitly passed objects.
/// For example, pass a NamedObject user, and you can use @user and @user.SomeProperty in your string.
/// </summary>
/// <param name="s">The string to be parsed.</param>
/// <param name="objects">A NamedObject array for objects too allow for parsing.</param>
public static string Interpolate(this string s, params NamedObject[] objects) {
System.Diagnostics.Debug.WriteLine(s);
List<NamedObject> namedObjects = new List<NamedObject>(objects);
Dictionary<NamedObject, Dictionary<string, string>> objectsWithProperties = new Dictionary<NamedObject, Dictionary<string, string>>();
foreach (NamedObject no in objects) {
Dictionary<string, string> properties = new Dictionary<string, string>();
foreach (System.Reflection.PropertyInfo pInfo in no.Object.GetType().GetProperties())
properties.Add(pInfo.Name, pInfo.GetValue(no.Object, new object[] { }).ToString());
objectsWithProperties.Add(no, properties);
}
foreach (Match match in Regex.Matches(s, @"@(\w+)(\.(\w+))?")) {
NamedObject no;
no = namedObjects.Find(delegate(NamedObject n) { return n.Name == match.Groups[1].Value; });
if (no.Name != null && match.Groups.Count == 4)
if (string.IsNullOrEmpty(match.Groups[3].Value))
s = s.Replace(match.Value, no.Object.ToString());
else {
Dictionary<string, string> properties = null;
string value;
objectsWithProperties.TryGetValue(no, out properties);
if (properties != null && properties.TryGetValue(match.Groups[3].Value, out value))
s = s.Replace(match.Value, value);
}
}
return s;
}
}
}
そして、ここにテストがあります：
using StringInterpolation;
namespace StringInterpolationTest {
class User {
public string Name { get; set; }
}
class Ticket {
public string ID { get; set; }
public string Priority { get; set; }
}
class Program {
static void Main(string[] args) {
User user = new User();
user.Name = "Joe";
Ticket previousTicket = new Ticket();
previousTicket.ID = "1";
previousTicket.Priority = "Low";
Ticket currentTicket = new Ticket();
currentTicket.ID = "1";
currentTicket.Priority = "High";
System.Diagnostics.Debug.WriteLine("User: @user, Username: @user.Name, Previous ticket priority: @previousTicket.Priority, New priority: @currentTicket.Priority".Interpolate(
new NamedObject("user", user),
new NamedObject("previousTicket", previousTicket),
new NamedObject("currentTicket", currentTicket)
));
}
}
}
これは Albin のバリアントよりもかなり多くのコードですが、ID を手動で設定する必要はありません (ただし、潜在的な補間のためにどのオブジェクトを「エクスポート」するかを事前に知っておく必要があります)。
みんなありがとう！