No, getting no error. It just won't store the value.

Never mind, looks like I don't need it anyway.

But thanks

And TreeDrowndownField stores the value?

The OptionalTreeDrowndownField extends the TreeDropdownField so I don't know why one would work and the other one doesn't. The only difference between the two I can think of is that if you do not select a value it tries to store a null value, but that should only be an issue if you don't select a value.

no, both of them didn't store the value.
But when I use this code:

new TreeDropdownField("InternLinkID", "Velg hvor artikkelen skal linkes til", "SiteTree"

This stores the value.

Then it should also work for:

new OptionalTreeDropdownField("InternLinkID", "Velg hvor artikkelen skal linkes til", "SiteTree"

yes, it should.
But I don't need that function after all.. :)

Been a long time since I posted this one :-) Thanks, Marijn

I´m trying to get the OptionalTreeDropDownField working under SS 2.4, as the code above doesn´t return any sitetree when using it under SS 2.4.

Obviuosly the method TreeDropdownField::gettree() has changed to TreeDropdownField::tree($request) in Version 2.4 (see doc: http://api.silverstripe.org/2.4/forms/fields-relational/TreeDropdownField.html#methodtree)

My first try was to just change the method name to tree() (without any param). But this results in an 'missing argument' error and doesn´t return anything.

So obviously you need to pass the parameter '$request' which is of the type 'SS_HTTPRequest'.

My problem: I don´t know how to generate a variable with the current SS_HTTPRequest.
Does anybody know how to correctly call the mehtod TreeDropdownField::tree($request), so that it returns the current Sitetree?

Hi Silverseba,

I had noticed that it didn't work, but didn't see the urgency of fixing it yet, your post encouraged me to though :)

As the OptionalTreeDropdownField is an extension of TreeDropdownField we don't need to generate the SS_HTTPRequest $request variable. It is passed by the calling function to our function. Below the full updated code of the OptionalTreeDropdownField.

<?php
/**
 * TreeDropdown-like field that gives you a tree of items including an empty field, using ajax.
 * Author: Marijn Kampf www.exadium.com
 * Date:  				24 Nov 2009
 * Version: 			2.0
 * Revision date:		17 June 2010
 * Changes: 			Updated to work with SilverStripe 2.4, tree function added.
 */
class OptionalTreeDropdownField extends TreeDropdownField {
	private static $postTree = '</ul>';

	/**
	 * Helper function to return the header (rather than defining same line twice).
	 */
	function preTree() {
		return '<ul class="tree"><li id="" class="l"><a>' . _t('OptionalTreeDropdownField.NONE', "(None)", PR_MEDIUM, 'Non selected value of a dropdown') . '</a>';
	}

	/**
	 * Return the site tree
	 * For version 2.3 and earlier
	 */
	function gettree() {
		echo $this->preTree();
		parent::gettree();
		echo $this->postTree;
	}

	/**
	 * Get the whole tree of a part of the tree via an AJAX request with empty / none item prepended.
	 *
	 * @param SS_HTTPRequest $request
	 * @return string
	 * for version 2.4 and later
	 */
	function tree($request) {
		return $this->preTree() . parent::tree($request) . $this->postTree;
	}
}