npbenjohnson / automapper.extensions.expressionmapping Goto Github PK

var mapper = new Mapper(new MapperConfiguration(cfg => {
    cfg.AddExpressionMapping();
	// Rest of your configuration
}));

// or if using the MS Ext DI:

services.AddAutoMapper(cfg => {
    cfg.AddExpressionMapping();
}, /* assemblies with profiles */);

    public class User
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

    public class Request
    {
        public int Id { get; set; }
        public int AssigneeId { get; set; }
        public User Assignee { get; set; }
    }

    public class UserDTO
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

    public class RequestDTO
    {
        public int Id { get; set; }
        public UserDTO Assignee { get; set; }
    }

ICollection<RequestDTO> requests = await context.Request.GetItemsAsync(mapper, r => r.Id > 0 && r.Id < 3, null, new List<Expression<Func<IQueryable<RequestDTO>, IIncludableQueryable<RequestDTO, object>>>>() { item => item.Include(s => s.Assignee) });
ICollection<UserDTO> users = await context.User.GetItemsAsync<UserDTO, User>(mapper, u => u.Id > 0 && u.Id < 4, q => q.OrderBy(u => u.Name));
int count = await context.Request.Query<RequestDTO, Request, int, int>(mapper, q => q.Count(r => r.Id > 1));

    static class Extensions
    {
        internal static async Task<TModelResult> Query<TModel, TData, TModelResult, TDataResult>(this IQueryable<TData> query, IMapper mapper,
            Expression<Func<IQueryable<TModel>, TModelResult>> queryFunc) where TData : class
        {
            //Map the expressions
            Func<IQueryable<TData>, TDataResult> mappedQueryFunc = mapper.MapExpression<Expression<Func<IQueryable<TData>, TDataResult>>>(queryFunc).Compile();

            //execute the query
            return mapper.Map<TDataResult, TModelResult>(mappedQueryFunc(query));
        }

        internal static async Task<ICollection<TModel>> GetItemsAsync<TModel, TData>(this IQueryable<TData> query, IMapper mapper,
            Expression<Func<TModel, bool>> filter = null,
            Expression<Func<IQueryable<TModel>, IQueryable<TModel>>> queryFunc = null,
            ICollection<Expression<Func<IQueryable<TModel>, IIncludableQueryable<TModel, object>>>> includeProperties = null)
        {
            //Map the expressions
            Expression<Func<TData, bool>> f = mapper.MapExpression<Expression<Func<TData, bool>>>(filter);
            Func<IQueryable<TData>, IQueryable<TData>> mappedQueryFunc = mapper.MapExpression<Expression<Func<IQueryable<TData>, IQueryable<TData>>>>(queryFunc)?.Compile();
            ICollection<Expression<Func<IQueryable<TData>, IIncludableQueryable<TData, object>>>> includes = mapper.MapIncludesList<Expression<Func<IQueryable<TData>, IIncludableQueryable<TData, object>>>>(includeProperties);

            if (f != null)
                query = query.Where(f);

            if (includes != null)
                query = includes.Select(i => i.Compile()).Aggregate(query, (list, next) => query = next(query));

            //Call the store
            ICollection<TData> result = mappedQueryFunc != null ? await mappedQueryFunc(query).ToListAsync() : await query.ToListAsync();

            //Map and return the data
            return mapper.Map<IEnumerable<TData>, IEnumerable<TModel>>(result).ToList();
        }
    }