How to use 2 expressions in EF Repository Pattern - entity-framework

Question

I have this method in my Generic EF Repository class
public class GenericRepository<T> : IGenericRepository<T> where T : class
{
public async Task<IEnumerable<T>> GetAllByExpression<T>(Expression<Func<T, bool>> expression,
Expression<Func<T, object>>[] includes) where T : class
{
if (expression != null)
{
IQueryable<T> query = context.Set<T>();
foreach(var include in includes)
{
query = query.Include(include);
}
var result = await query.Where(expression)
.ToListAsync();
return result;
}
else
{
throw new ArgumentNullException("Invalid expression.");
}
}
}
I do not know how to use the "Include" to it. Basically what I want to get is like this =>
return await context.PropertyChargesRates.Where(x => x.BuildingId == buildingId)
.Include(x => x.PropertyChargeType)
.ToListAsync();
This is how I try to utilize this function:
public async Task<IEnumerable<PropertyChargesRate>> GetPropertyChargeRates(int buildingId)
{
try
{
var g = new GenericRepository<PropertyChargesRate>(context);
var result = g.GetAllByExpression<PropertyChargesRate>(x => x.BuildingId == buildingId, ** CANT FIGURE OUT HOW TO CALL THIS PART YET **);
return result;
}
catch (Exception ex)
{
return null;
}
}

Answer 1

Implementation that you are looking for could look like this:
public IEnumerable<T> GetAllByExpression<T>(
YourDBContext context,
Expression<Func<T, bool>> expression,
Func<IQueryable<T>, IQueryable<T>> includes) where T : class
{
if (expression != null)
{
IQueryable<T> query = context.Set<T>();
query = includes(query);
var result = query.Where(expression)
.ToList();
return result;
}
throw new ArgumentNullException(nameof(expression), "Invalid expression.");
}
And usage would look like this:
repository.GetAllByExpression<YourEntity>
(YourDbContext,
YourWhereExpression,
(q)=> q.Include(i=> i.YourInclude1)
.Include(i2=> i2.YourInclude2));