How can i loop over all the childs of childs?

Question

In top of script i added:

public Transform parentToSearch;

Then:

private void OnGUI()
    {
        if (hasDescription == true && clickForDescription == true)
        {
            foreach (Transform child in parentToSearch)
            {
                if (child.GetComponent<ItemInformation>() != null)
                {
                    ItemInformation iteminformation = child.GetComponent<ItemInformation>();
                    if (child.name == objectHit)
                    {
                        var centeredStyle = GUI.skin.GetStyle("Label");
                        centeredStyle.alignment = TextAnchor.UpperCenter;
                        GUI.Label(new Rect(Screen.width / 2 - 50, Screen.height / 2 - 25, 100, 50), iteminformation.description, centeredStyle);
                    }
                }
            }
        }
    }

But when i make the loop:

foreach (Transform child in parentToSearch)

It will find the first level childs of the first parent but this childs have also childs and so on. And i want to loop all the childs and childs of childs under the Transform.

For example in the Hierarchy i have:

• Test
  • Test1
  • Test2
  • Test3
    • Test31
    • Test32
  • Test4
  • Test5
    • Test51

So now it will loop only over Test 1,2,3,4,5 but I want also to loop over Test31,Test32,Test51

Answer 1

You can use a recursive call

void Process(Transform parent, int level = 0)
{
    // TODO: process the parent object.

    foreach (Transform child in parent) {
        // The Process method calls itself. This is the recursive call.
        Process(child, level + 1);
    }
}

You never have to process the child, as each child will become the parent in the recursive call.

I also added a level information allowing you to indent children when printing, adding a label etc. (optional).

---

If you don't want to process the top-level parent, you can instead process the children.

void Process(Transform parent, int level = 0)
{
    foreach (Transform child in parent) {
        // TODO: process the child object.

        // Process next deeper level
        Process(child, level + 1);
    }
}

---

Applied to your problem:

private void OnGUI()
{
    if (hasDescription && clickForDescription)
    {
        ProcessOnGUI(parentToSearch);
    }
}

void ProcessOnGUI(Transform parent, int level = 0)
{
    foreach (Transform child in parent) {
        var iteminformation = child.GetComponent<ItemInformation>();
        if (iteminformation != null && child.name == objectHit) {
            var centeredStyle = GUI.skin.GetStyle("Label");
            centeredStyle.alignment = TextAnchor.UpperCenter;
            GUI.Label(new Rect(
                  Screen.width / 2 - 50 + 20 * level, // <== INDENTATION
                  Screen.height / 2 - 25, 100, 50),
                iteminformation.description, centeredStyle);
        }

        // Process next deeper level
        ProcessOnGUI(child, level + 1);
    }
}