Create array from nested lists

Question

A little difficult to explain, but here goes... (using .net 4.5, C#)

We currently have a list of items ( as per below "User") which contains a list of column objects. ie.

 public class TableColumn
{
    public string ColumnHeader { get; set; }
    public string ColumnValue { get; set; }
    public int ColumnWidth { get; set; }  
}

public class User
{
    public string Username { get; set; }
    public string Address1 { get; set; }
    public int Age { get; set; }

    public List<TableColumn> Columns { get; set; }
}

We are working with JQGrid where we are required to pass back Json.

without the nested list we would use :-

var aaData = PatList.Select(d => new string[] { 
              d.Username ,
              d.Address1 ,
              d.Age}).ToArray();

 return Json(new
        {
            sEcho = param.sEcho,
            aaData = aaData,
            iTotalRecords = Convert.ToInt32(totalRowsCount.Value),
            iTotalDisplayRecords = Convert.ToInt32(filteredRowsCount.Value)
        }, JsonRequestBehavior.AllowGet);

which works great.

What we are struggling with is how to add in the list of columns.

   var aaData = PatList.Select(d => new string[] { 
              d.Username ,
              d.Address1 ,
              d.Age,
              d.Columns.forEach(????)}).ToArray();

so the columns are related to a user.

Hopefully that makes sense. Any assistance would be appreciated.

If you need your data output in JSON format (i.e. your list of Users and their associated object graphs) you might want to consider using a JSON serializer. Have a look at [Does .NET 4 have a built-in JSON serializer/deserializer?](http://stackoverflow.com/questions/3275863/does-net-4-have-a-built-in-json-serializer-deserializer). — Todd Bowles, Jan 14 '14 at 11:53

score 1 · Accepted Answer · answered Jan 14 '14 at 11:43

1

You can do something like this:

var aaData = PatList.Select(d => (new string[] { 
        d.Username,
        d.Address1,
        d.Age.ToString()
    }.Union(d.Columns.Select(c => c.ColumnHeader))).ToArray()
).ToArray();

This generates for every User in PatList an array with Username, Address1, Age & all ColumnHeaders.

answered Jan 14 '14 at 11:43

Raidri

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thank you This worked, however, it removed many empty columns, which if im representing within a table, id still need. Managed to get around this by using concat rather than union var aaData = PatList.Select(d => (new string[] { d.Username, d.Address1, d.Age.ToString() }.Concat(d.Columns.Select(c => c.ColumnHeader))).ToArray() ).ToArray(); – Simon Jan 14 '14 at 11:55
Yes, `Union` removes duplicate / empty headers. – Raidri Jan 14 '14 at 11:58

Create array from nested lists

1 Answers1