using System.Linq.Expressions;
using System.Reflection;
using Umbraco.Cms.Core.Models.PublishedContent;
using Umbraco.Cms.Infrastructure.ModelsBuilder;
// same namespace as original Umbraco.Web PublishedElementExtensions
// ReSharper disable once CheckNamespace
namespace Umbraco.Extensions;
///
/// Provides extension methods to models.
///
public static class PublishedElementExtensions
{
///
/// Gets the value of a property.
///
public static TValue? ValueFor(
this TModel model,
IPublishedValueFallback publishedValueFallback,
Expression> property,
string? culture = null,
string? segment = null,
Fallback fallback = default,
TValue? defaultValue = default)
where TModel : IPublishedElement
{
var alias = GetAlias(model, property);
return model.Value(publishedValueFallback, alias, culture, segment, fallback, defaultValue);
}
// TODO: that one should be public so ppl can use it
private static string GetAlias(TModel model, Expression> property)
{
if (property.NodeType != ExpressionType.Lambda)
{
throw new ArgumentException("Not a proper lambda expression (lambda).", nameof(property));
}
var lambda = (LambdaExpression)property;
Expression lambdaBody = lambda.Body;
if (lambdaBody.NodeType != ExpressionType.MemberAccess)
{
throw new ArgumentException("Not a proper lambda expression (body).", nameof(property));
}
var memberExpression = (MemberExpression)lambdaBody;
if (memberExpression.Expression?.NodeType != ExpressionType.Parameter)
{
throw new ArgumentException("Not a proper lambda expression (member).", nameof(property));
}
MemberInfo member = memberExpression.Member;
ImplementPropertyTypeAttribute? attribute = member.GetCustomAttribute();
if (attribute == null)
{
throw new InvalidOperationException("Property is not marked with ImplementPropertyType attribute.");
}
return attribute.Alias;
}
}