c#: deserializing a JSON containing a local property

Question

I deserialize a JSON which looks like this:

{
    "id": "FF478946-8536-4295-AC58-F6C3D2B4E5CC",
    "title": "This is a Title with an escaped variable: {VariableName}",
    "weight": 50
}

To a corresponding object using Newtonsoft:

public class Event
{
    public string Id { get; set; }
    public string Title { get; set; }
    public int Weight { get; set; }
}

And then I want to print the string Title which refers to a local string property in code. VariableName

private string VariableName { get; set; }
private Event CurrentEvent { get; set; }

public void OnNextEventClicked()
{
   Log(CurrentEvent.Title);
}

I tried to somehow escape the variable with different approaches like backslash ("title": "This is a Title with an escaped variable: \"VariableName\"") or curly brackets like in the code above but i failed... C# always treats the escaped variable as a normal part of the Title string.

What's the best way to do this? Thanks!

Answer 1

Like @Roman Ryzhiy pointed out in the comments, there is already a good threat about dynamic string interpolation.

The perfect solution for me was the following based on this answer.

A helper method using System.Linq.Dynamic:

public string ReplaceMacro(string value, object @object)
{
    return Regex.Replace(value, @"{(.+?)}", 
    match => {
        var p = Expression.Parameter(@object.GetType(), @object.GetType().Name);                
        var e = System.Linq.Dynamic.DynamicExpression.ParseLambda(new[] { p }, null, match.Groups[1].Value);
        return (e.Compile().DynamicInvoke(@object) ?? "").ToString();
    });
}

My full solution:

JSON:

{
"id": "FF478946-8536-4295-AC58-F6C3D2B4E5CC",
"title": "This is a Title with an escaped variable: {TitleReplacement.VariableName}",
"weight": 50
}

C#:

Data Class:

public class Event
{
    public string Id { get; set; }
    public string Title { get; set; }
    public int Weight { get; set; }
}

Class with replacement string:

public class TitleReplacement
{
    public string VariableName { get; set; }
}

Call it like:

private Event CurrentEvent { get; set; }
private TitleReplacement Replacement { get; set; }

public void OnNextEventClicked()
{
    Log(ReplaceMacro(CurrentEvent.Title, Replacement);
}