Is it possible to create a Dynamic tree structure using the ExpandoObject?

Question

at the moment I am using the ExpandoObject to dynamically store firstname and surname.

e.g.

   // Create Expando object for testing
   dynamic employee = new ExpandoObject();

   // Dynamically add the fields to the expando            
   ((IDictionary<String, Object>)employee).Add("FirstName", "John");
   ((IDictionary<String, Object>)employee).Add("Surname", "Smith");

I was wondering if it is possible to dynamically store the fields into a tree structure so that i could have the parent field called Name, and then two child fields called Firstname and Surname. Ideally this could potentially be expanded to included more sub levels. I've done some psudo code below to demonstrate ideally how I would like it to work. (of course this code currently causes errors)

// Create Expando object for testing
dynamic employee = new ExpandoObject();

// Dynamically add the Name
((IDictionary<String, Object>)employee).Add("Name", "");

//Dynamically add the firstname and surname to employee.Name
((IDictionary<String, Object>)employee.Name).Add("FirstName", "John");
((IDictionary<String, Object>)employee.Name).Add("Surname", "Smith");

Expando? Is that some Harry Potter spell? +1 for interesting question — sehe, May 23 '11 at 15:01
@sehe, http://msdn.microsoft.com/en-us/library/system.dynamic.expandoobject.aspx — George Duckett, May 23 '11 at 15:03
@sehe, Thought you'd never heard of it before and would appreciate a link. nm — George Duckett, May 23 '11 at 15:12
@George: I _had_ never heard of it. It's a good find, that's why I expressed my surprise. Sorry if I sometimes get carried away too much on an informational site like SO — sehe, May 23 '11 at 15:18

sehe · Accepted Answer · 2011-05-23T15:17:00.830

6

What stops you from doing

 dynamic parent = new ExpandoObject();
 parent.Nick = "Dad";
 parent.Name = new ExpandoObject();
 parent.Name.FirstName = "John";
 parent.Name.MiddleName = "Tweeds";
 parent.Name.SurName = "Doe";

 parent.Spouse = new ExpandoObject();
 parent.Spouse.Nick = "Sweety";
 parent.Children = new [] {
     new ExpandoObject(),
     new ExpandoObject()
 };
 parent.Children[0].Nick = "P-J";
 parent.Children[0].Name = "Pete-Jay";
 parent.Children[1].Nick = "Tammie";
 parent.Children[1].Name = "Tamara";

Or similar? You wouldn't exactly get tree traversal for free, but that's basically a given when not using strongtypes nodes

Update; I just compiled and ran this using Mono C# compiler on Windows XP. Not even having MS.NET 4.0 installed :)

edited May 23 '11 at 15:17

answered May 23 '11 at 15:11

sehe

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Yeah, that is an option but as its quite new i was wondering if anyone had done anything interesting with it around tree/folder views. thanks for answer – kevchadders May 24 '11 at 07:40
tree/folder views? that wasn't part of your question as I read it – sehe May 24 '11 at 08:19
True, i just mentioned it as i was looking into expanding it to included more sub levels in my post similar to a tree view. – kevchadders May 24 '11 at 08:58

jbtule · Answer 2 · 2014-02-12T14:51:23.520

Using the Open source Dynamitey (can be install via nuget, and is a Portable Class Library), you can make expandoobject graphs like this:

  using Dynamitey.DynamicObjects;
  ...

  dynamic New = Builder.New<ExpandoObject>();

  var person = New.Person(
      Name: New.Name(FirstName:"John", SurName:"Smith")
  );

You can also take a bunch of nested IDictionary<string,object> and make them act like a dynamic object with nested dynamic object properties by using:

using Dynamitey.DynamicObjects.Dictionary = DynamicDict;
...

dynamic obj = new DynamicDict(nestedDictionaries);

Is it possible to create a Dynamic tree structure using the ExpandoObject?

2 Answers2