Iterators are a core concept for printing lists of items. There are different types but at the top level you will use two of them: Children of Folder and Links of Item. The iterators themselves will work a bit differently depending on the input and to get the recursion effect you have to put a “recursive” function into either the folder or item output. The core idea is that the iterated formatter, for example a LIST, is run against all the sub items again when it encounters a “recursive” function in the output.
Children of Folder
Use this when you want to iterate over a whole folder structure, with a selection of a folder or a combination of folders and items. For this to be effective you will normally have a “recursive” function in the Folder output of the List. As an example see the Simple Bullet List formatter in the default templates.
Links of Item
The link iterator is a bit more complicated to use in terms of formatting since the recursion treats the top item and the recursion item the same way, unlike the children iterator where a folder has its own formatting template.
For a simple example see the “Iterate Links” LIST, it will create a recursive bulleted list of downlinks from all selected items. As you can see the formatting looks the same for each.
A more typical example is to combine a regular item list with a FORMAT and an additional LIST purely for the iteration, without recursion. An example for this is the “List of Items” LIST. It uses a children iterator to list all items, a formatter to extract the links (“Downlinks with Condition and Error and Label”) which in turn uses “Downlinks” to render the item’s downlinks.