C# help - finding parent of list items

[ringo747]

Hi,

Hopefully I can explain the problem well enough. I have a hierarchy of terms for example:

L1
L1 -> L2
L1 -> L2 -> L3
L1 -> L2 -> L3 -> Ln

Each term has a property called 'Parent'. What is the best way to return the L1 and L2 terms for every single term.

If I am currently at location L1, I just need L1.Name returned
If I am currently at location L2, I just need L1.Name and L2.Name returned
...
for every other location I need L1.Name and L2.Name

What would the quickest way of finding these values be?

This is my code so far but I think its not good.

private Term GetParent(Term t)
        {
            if (t.Parent == null)
            {
                // this is L1
                return t;
            }
            else if (t.Parent.Parent == null)
            {
                // this is L2
                return t;
            }
            else
            {
                return GetParent(t.Parent);
            }
        }

This code will either return an L1 or L2 and then I can check the returned value to see if it has a parent. If it does then I know the returned term was L2.

Important to note that there will be multiple terms at each of the levels.

 

[csmager]

How do you want both names returned - L1 and L2? Concatenated?

 

[ringo747]

Is it possible to get them returned as two separate values?

If the term is actually an L1 term then I'd expect the l2 value to be null.

 

[csmager]

I'd probably add a couple of properties like this. Not tested, might not work...

public Term L1Parent
{
     get
          {				
               for (Term t = Parent; t != null; t = t.Parent)	
               {
                    if (t.Parent == null) return t;
               }
		
               return null;
          }
}

public Term L2Parent
{
     get
          {			
               for (Term t = Parent; t != null; t = t.Parent)	
               {
                    if (t.Parent != null && t.Parent.Parent == null) return t;
               }
               return null;
          }
}

EDIT: Change "for (t = Parent..." to "for (t = this...") if you want them to return themselves if they are L1 or L2.

 

[ringo747]

ok thanks will give that a go.

 

[Randomface74]

original code is fine - what's the problem?

 

[ZombieFan]

Returns a list containing all parents of the supplied Term (untested!):

        private List<Term> GetParents(Term t)
        {
            List<Term> terms = new List<Term>();

            while (t.Parent != null)
            {
                terms.Add(t.Parent);
                t = t.Parent;
            }

            return terms;
        }

 

[GravyMonster]

original code is fine - what's the problem?

Agreed, the recursive call you have in the third condition should cover all levels. Whats the problem with it?

 

[ringo747]

Agreed, the recursive call you have in the third condition should cover all levels. Whats the problem with it?

Grand. Just wanted to make sure it was the best way of doing it. As long as it is fairly bullet proof.