inabox/InABox.Mobile/InABox.Mobile.Shared/Converters/StringToBooleanConverter.cs

using System;
using System.ComponentModel;
using System.Globalization;
using Xamarin.Forms;

namespace InABox.Mobile
{
    public class StringToBooleanConverter : UtilityConverter<String,bool>
    {
        public bool HasValue { get; set; }

        protected override bool Convert(string value)
        {
            var empty = String.IsNullOrWhiteSpace(value);
            return HasValue 
                ? !empty 
                : empty;
        }

        public StringToBooleanConverter()
        {
            HasValue = true;
        }
        
    }
    
    public class StringWithDefaultValueConverter : IValueConverter
    {
        
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return String.IsNullOrWhiteSpace(value as String)
                ? parameter
                : value;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}