Creating a new instance of an object whose properties were read from XML

Question

I'm stuck at some point in my understanding of how XML deserialization could help me define my classes through XML files.

Let's say I have a new XML definition file for 2 kind of monsters, like this:

<MonstersCollection>
  <Monsters>
    <Monster>
      <MonsterName>Dragon<MonsterName>
      <HitPoints>100</Hitpoints>
    </Monster>
    <Monster>
      <MonsterName>Beast<MonsterName>
      <HitPoints>75</Hitpoints>
    </Monster>
  </Monsters>
</MonstersCollection>

Using XML deserializer, I get a nice List with my 2 differents monsters in it and everything is fine.

But how could I easily and elegantly instantiate a new Dragon Monster or Beast Monster elsewhere?

Should I have to clone the corresponding object in the List, or is there any other way to do this?

Ultimately, I would like to be able to do something as simple as:

MonsterType monsterType = MonsterType.Dragon
Monster newMonster = new Monster(monsterType)

And have the constructor automatically populate this new object properties with the Dragon data from the XML definition file.

Any help would be greatly appreciated.

If you are looking for a utility to deep-clone your `Monster` object, see [Deep cloning objects](https://stackoverflow.com/questions/78536/deep-cloning-objects/), specifically [this answer](https://stackoverflow.com/questions/78536/deep-cloning-objects/1834578#1834578) which uses `XmlSerializer`. — dbc, Nov 29 '16 at 20:19
I went with Chintana Meegamarachchi solution but this is nonetheless very interesting, thank you for the links. — John-P, Dec 02 '16 at 08:54

score 0 · Accepted Answer · answered Nov 30 '16 at 06:47

One way to go is to use factory pattern. Provided you have a collection of monsters you got from your XML file, you should create a factory class which will create a monster given a monster type. This way your creation logic is separated from your model

you code will look something like ..

public class MonsterFactory
{
    private readonly Monster[] _monsters;

    public MonsterFactory(Monster[] monsters)
    {
        _monsters = monsters;
    }

    public Monster CreateMonster(MonsterType monsterType)
    {
        return _monsters.First(e => e.MonsterName == monsterType);
    }
}

public enum MonsterType
{
    Dragon,
    Beast
}

public class Monster
{
    public MonsterType MonsterName { get; set; }
    public int HitPoints { get; set; }
}

and the call would be like

var dragon = new MonsterFactory(listOfMonsters).CreateMonster(MonsterType.Dragon);

Hope this helps

Creating a new instance of an object whose properties were read from XML

1 Answers1