Sort a list and all its nested objects using LINQ

Question

There is an organisation with several departments and each department has a few employees.

I have created the following object model:

public class O         


        

Answer 1

You can sort before :

    organisations.ToList().ForEach(o => o.Departments = o.Departments.OrderBy(d => d.Code).ToList());
    organisations.SelectMany(o => o.Departments).ToList().ForEach(d => d.Employees = d.Employees.OrderBy(e => e.Name).ToList());

And then use the list already sorted

        var legalEntitiesCollectionByType = new Dictionary>
        {
            {
                "Institutional", organisations
                    .Where(x => x.Type == "Institutional")
                    .ToList()
            },
            {
                "Retail", organisations
                    .Where(x => x.Type == "Retail")
                    .ToList()
            }
        };

NB : the sort is not in place, you can achieve this using a comparer

        organisations.ToList().ForEach(o => o.Departments.Sort(CreateCustomComparison));
        organisations.SelectMany(o => o.Departments).ToList().ForEach(d => d.Employees.Sort(CreateCustomComparison));