EDIT

<?php

// $Id $

/**

 * @file

 * Allows users to create nodes instead of selecting them from a list

 *

 * @author Obslogic (Mike Smith aka Lionfish)

 */

/**

 * Implementation of hook_help

 */

function expertsdb_addnode_help($section='')

{

	$output = '';

	switch ($section)

	{

		case "admin/help#expertsdb_addnode":

			$output = '<p>'.t("Provides an option to the user to create a new node type.").'</p>';

			break;

	}

	return $output;

}

/**

 * Implementation of hook_widget_info.

 * Specifies the label and that it is a widget for the nodereference field type

 */

function expertsdb_addnode_widget_info()

{

	return array(

    'expertsdb_addnode_select' => array(

      'label' => 'Expertsdb AddNode List',

      'field types' => array('nodereference'),

	),

	);

}

/**

 * Implementation of hook_widget

 */

function expertsdb_addnode_widget($op, &$node, $field, &$node_field)

{

	//need this module for the_nodereference_potential_references function.

	include_once(drupal_get_path('module', 'content').'/nodereference.module');

	if ($field['widget']['type'] == 'expertsdb_addnode_select')

	{

		switch ($op) {

			case 'prepare form values':

				//puts node_field (original) values into a temporary bit of the array called default nids

				$node_field_transposed = content_transpose_array_rows_cols($node_field);

				$node_field['default nids'] = $node_field_transposed['nid'];

				break;

			case 'form':

				//adds javascript

				$path = drupal_get_path('module','expertsdb_addnode');

				drupal_add_js($path . '/expertsdb_addnode.js');

				$form = array();

				$selectedoptions = array();

				//gets the list of all potential nodes that could be referenced

				$options = _nodereference_potential_references($field, true);

				foreach ($options as $key => $value) {

					$options[$key] = _nodereference_item($field, $value);

				}

				//string describing what can be added. If there's one type it will be that, otherwise it will be

				//just 'item'.

				$typedesc = "";

				$type_count=0;  //counts up how many types there are

				$type_list=array(); //list of the types

				//If referenceable_types is not an array, give up.

				if (!is_array($field['referenceable_types']))

				{

					return $form;

				}

				//add referenceable types to the $type_list array

				foreach ($field['referenceable_types'] as $ref_type)

				{

					if ($ref_type)

					{

						$typedesc = $ref_type;

						$type_count++;

						$type_list[] = $ref_type;

					}

				}

				//if there are no types available, give up.

				if ($type_count==0)

				{

					//@todo Need to display something explaining the problem.

					return $form;

				}

				//converts the type name to a human readable one

				$typedesc = node_get_types('type', $typedesc);

				$typedesc = $typedesc->name;

				//If there's more than one type available then we use the term 'item' to describe them

				if ($type_count>1)

				{

					$typedesc = "item";

				}

				$fieldname=$field['field_name'];

				$title=t($field['widget']['label']);

				//$createmsg is a message such as "Create a new _fund_ or _pot_" with links in.

				$createmsg=_expertsdb_addnode_create_new_message($type_count, $fieldname, $type_list);

				$prefix = '';

				$suffix = '';

				$subsuffix = "";

				//this prefix builds the table headers etc.

				$prefix = "";

				$prefix.= "<b>$title:</b>";

				$prefix.= '<table class="expertsdb-addnode-select-table">';

				$prefix.= "<tr>";

				$prefix.= '<th class="expertsdb-addnode-select column-left">';

				$prefix.= "<a href='javascript:;' id='$fieldname' class='expertsdb_addnode_select_link'>";

				$prefix.= t("Select</a> !typedesc already available</th>", array('!typedesc'=>"$typedesc"));

				$prefix.= '<th class="expertsdb-addnode-select-table-header column-right">';

				$prefix.= $createmsg;//msg that says 'Create an item' or whatever

				$prefix.= "</th>";

				$prefix.= "</tr>";

				$prefix.= "<tr>";

				$prefix.= '<td class="expertsdb-addnode-select column-left">';

				//select box goes here

				$suffix.= "</td>";

				$suffix.= '<td class="expertsdb-addnode-select column-right">';

				//the subforms go here

				//the last subform must suffix with:

				$subsuffix.= "</td>";

				$subsuffix.= "</tr>";

				$subsuffix.= "</table>";

				///This hidden form element has been moved above the subforms to allow it to be processed before their

				///#after_build functions run (as they will need the values in this element).

				//whether we've selected something from the select box, or created a new item

				//is stored in this hidden field. So the submit functions know what to do.

				$form["expertsdb_addnode_".$fieldname] = array(

          '#type' => 'hidden',

          '#title' => t('selection or creation'),

          '#default_value' => '',

          '#attributes' => array (

            'class' => 'expertsdb_addnode_source',

				),

				);

				$weight = $field['weight'];

				//select box

				$form[$fieldname]['#tree'] = TRUE;

				$form[$fieldname]['nids'] = array(

          '#type' => 'select',

          '#title' => '', //no title for this bit

          '#default_value' => $node_field['default nids'],

          '#multiple' => TRUE, // @todo: set this to the original multiple value and fix the bug, which makes this module disfunctional, if this is set to FALSE

          '#options' => $options,

          '#required' => $field['required'],

          '#description' => $field['widget']['description'],

          '#prefix' => $prefix,

          '#suffix' => $suffix,

          '#size' => 15,

          '#weight' => $weight,

          '#attributes' => array(

				//'style' => 'width:90%',

            'class' => "expertsdb_addnode_select",

            'id' => "$fieldname",

				),

				);

				//loops through the types this field can be.

				foreach ($type_list as $typename)

				{

					$weight = $weight + 0.1;//puts them in an order.

					$subnode = array('uid' => $node->uid, 'type' => $typename);

					//the name of the array below this field type, needed to divide the subforms.

					$subfieldname = 'node_'.$typename;

					$form[$fieldname][$subfieldname] = array(

            '#type' => 'subform',

            '#id' => $typename.'_node_form',

            '#arguments' => array($subnode),

            '#weight' => $weight,

            '#prefix' => "<span class='expertsdb_addnode_form $fieldname' id='$typename'>",

            '#suffix' => "</span>",

            '#after_build' => array('subform_element_build_subform','expertsdb_addnode_fix_subform'),

            '#fieldname' => $fieldname,

            '#extra_form' => array("#fieldname"=>$fieldname),

					);

				}

				//updates the last suffix to include the subsuffix (which closes the table)

				$form[$fieldname][$subfieldname]['#suffix'] .= $subsuffix;

				//add submit handlers:

				//Add the nids of the newly created sub-nodes to the node

				$form['#submit']['expertsdb_addnode_addnids_submit'] = array();

				//the subform element submit handler

				$form['#submit']['subform_element_submit'] = array();

				//the handler for the base node (todo: Is this still necessary, I think subform_element might do this)

				$form['#submit']['node_form_submit'] = array();

				// @TODO: add the current author to the subform

				return $form;

			case 'process form values':

				$node_field = content_transpose_array_rows_cols(array('nid' => $node_field['nids']));

				break;

			case 'submit':

				break;

		}

	}

}

/**

 * This is called as an #after_build function for each subform.

 *It 1) Disables the subform's validation etc if it's unused

 *   2) Removes the subform's buttons.

 */

function expertsdb_addnode_fix_subform($form_element, &$form_values)

{

	//get the subform array (from the subform_element module)

	global $subforms;

	//the type of node to create

	$nodetype = $form_element['#arguments'][0]['type'];

	//the name of the field the expertsdb_addnode widget is for

	$current_fieldname = $form_element['#fieldname'];

	//for each field in the form, look for expertsdb_addnode_[blah]

	foreach($form_values as $key => $value)

	{

		//if the field key begins 'expertsdb_addnode_' then it's one of the hidden fields, we use these to identify the names of potential subforms

		if (strpos($key, 'expertsdb_addnode_') === 0)

		{

			//get the fieldname (the bit after the 'expertsdb_addnode_' in the key).

			$fieldname = substr($key, 18);

			if ($fieldname == $current_fieldname)

			{

				//find out which subform's the source (it will be the value of this key).

				$source = $value;

				//if it's not '' then we're creating a new node. (if it is '' then we must be using the select box).

				//in other words, we disable subform processing if $source = '' or it's not related to this subform

				$disable = TRUE;

				if (strlen($source)>0) //if we're not using the select box...

				{

					if ($source == $nodetype) //and we've chosen this subform over any other

					{

						$disable = FALSE;

					}

				}

				if ($disable) //disable this subform as it's not being used.

				{

					$form_element['#validate'] = array();

				}

			}

		}

	}

	//Remove submit and preview buttons from the subform.

	$form_element['#form']['submit']['#attributes'] = array(

    'style' => 'height:0px; visibility:hidden;',

	);

	$form_element['#form']['preview']['#attributes'] = array(

    'style' => 'height:0px; visibility:hidden;',

	);

	// bugfix

	global $user;

	$form_element['#form']['author']['name']['#value'] = $user->name;

	// disable authoring information

	foreach (array('preview', 'submit', 'delete', 'author','options') as $name) {

		$form_element['#form'][$name]['#access'] = FALSE;

	}

	return $form_element;

}

/**

 * Called as a main form submit handler. It submits the subforms and gets the nids then puts them into

 * the main node.

 */

function expertsdb_addnode_addnids_submit($form_id, &$form_values)

{

	//copied from subform_element_submit, allows us to get hold of the redirects and get the nids from them

	global $subforms;

	if (isset($subforms)) {

		foreach ($subforms as $key => $subform) {

			if (!isset($subform['#submitted'])) {

				$subforms[$key]['#submitted'] = TRUE;

				$redirect = subform_element_call('drupal_submit_form', $subform['#post']['form_id'], $subform);

				$fieldname = $subform['#fieldname'];

				$split = explode("/", $redirect);

				$newnid = $split[1];

				//unset the current array, and replace it with a new array.

				//note that as multiselect is currently set, this is an array

				// @todo allow multi/single select!!

				unset($form_values[$fieldname]['nids']);

				$form_values[$fieldname]['nids'] = array ( $newnid => $newnid );

			}

		}

		return $redirect;

	}

}

/**

 * This outputs HTML for the 'create new nodetype' link message.

 * @param $type_count

 *   Number of types that could be added

 *

 * @param $fieldname

 *   The fieldname of this expertsdb_addnode field

 *

 * @param $type_list

 *   List of types

 */

function _expertsdb_addnode_create_new_message($type_count, $fieldname, $type_list)

{

	$msg="";

	$spanmsg.= "<span id='$fieldname' class='expertsdb_addnode_links'>";

	//if there's only one type then the message is of the form "Create a new blah"

	if ($type_count==1)

	{

		$atype=$type_list[0];

		$typedesc = node_get_types('type', $atype);

		$typedesc = $typedesc->name;

		//pretransmsg is message before translation.

		$pretransmsg = "or <a href='javascript:;' class='expertsdb_addnode_item !fieldname' id='!atype'>";

		$pretransmsg.= "!spanmsg";

		$pretransmsg.= "create a new !typedesc";

		$pretransmsg.= "</span>";

		$pretransmsg.= "</a>";

		$vars = array('!fieldname' => $fieldname, '!atype' => $atype, '!spanmsg' => $spanmsg, '!typedesc' => $typedesc);

		$msg.= t($pretransmsg, $vars);

	}

	//if there's more than one type then the message is of the form "Create a new blah or blah"

	if ($type_count>1)

	{

		$vars = array();

		$msg.= t("or create a new ");

		$tempcnt=0;

		foreach ($type_list as $atype)

		{

			$typedesc = node_get_types('type', $atype);

			$typedesc = $typedesc->name;

			$msg.= "<a href='javascript:;' class='expertsdb_addnode_item $fieldname' id='$atype'>";

			$msg.= $spanmsg;

			$msg.= "$typedesc";

			$msg.= "</span>";

			$msg.= "</a>";

			$tempcnt++;

			if ($tempcnt == $type_count-1)

			{

				$msg.= t(" or ");

			}

			else

			{

				$msg.= t(", ");

			}

		}

	}

	$msg .= "</span>";

	return $msg;

}