EDIT

<?php

// at the moment we are using a static meta.xml file

define ("METADATA_FILE_NAME", "meta.xml");

define ("STATIC_DIR", "/static/");

define ("ARCHIVE_ROOT_DIR", "dwca_export/");

define ('FILE_MAP', 'dwca_export_archive_descriptor_file_map');

define ('FILE_EXTENSION', ".txt");

//$view_all_names_except_description = array('classification', 'specimen', 'reference', 'image', 'distribution');

/**

 * Implements hook_menu().

 */

function dwca_export_menu() {

	$items = array();

	$items['admin/config/system/dwca_export'] = array(

		'title' => 'Darwin Core Archive export',

		'description' => t('Create a DarwinCore Archive of this scratchpad.'),

		'page callback' => 'drupal_get_form',

		'page arguments' => array('dwca_export_config_form'),

		'access arguments' => array('access DwC-A export settings'),

		'type' => MENU_NORMAL_ITEM,

		//'file' => 'dwca_export.admin.inc'

	);

	$items['dwca_export'] = array(

		'page callback' => 'dwca_export_deliver_archive',

		'access arguments' => array('access content'),

		'type' => MENU_CALLBACK

	);

	return $items;

}

function dwca_export_view_names_array(){

	$view_names = array('classification', 'specimen', 'reference', 'image', 'distribution');

	return $view_names;

}

/**

 * Implementation of hook_views_api()

 *

 * drupal will load dwca_export.views_default.inc when this hook is implemented

 */

function dwca_export_views_api() {

	return array(

		'api' => 3.0

	);

}

/**

* Implementation of hook_ctools_plugin_api().

*/

function dwca_export_ctools_plugin_api(){

	list($module, $api) = func_get_args();

	if($module == "strongarm" && $api == "strongarm"){

		return array(

      "version" => 1

		);

	}

}

/**

 * Form function, called by drupal_get_form()

 * in dwca_export_menu().

 */

function dwca_export_config_form($form, &$form_state) {

	global $base_url;

	$form['dwca_export_info'] = array(

		'#markup' => '<p>For general information on the DarwinCore Archive format please refer to  '

		. l('GBIF - Standards and Tools - Darwin Core Archives', 'http://www.gbif.org/informatics/standards-and-tools/publishing-data/data-standards/darwin-core-archives/')

		.'</p>'

	);

	$form['dwca_export_execute'] = array(

		'#markup' => '<p>The DarwinCore Archive export is available at '. l('dwca_export', 'dwca_export').'</p>'

		//'#type' => 'button',

		//'#value' => t('Export Scratchpad to DarwinCore Archive'), 

	  //'#weight' => 19,

	);

	$form['dwca_export_view_mapping'] = dwca_export_select_view_form();

	$form['#submit'][] = 'dwca_export_config_form_submit';

	return system_settings_form($form);

}

function dwca_export_select_view_form() {

	$views = array(

    		'#type' => 'fieldset',

    		'#title' => t('View to file mapping'),

    		//'#tree' => TRUE,

  	);

	foreach(variable_get(FILE_MAP) as $dwca_filename => $view_data){

		if ($dwca_filename == 'description') {

		$views[$dwca_filename] = array (

					'#type' => 'fieldset',

  					'#title' => t('DESCRIPTIVE DATA TYPES'),

				  	'#weight' => 3,

				  	'#collapsible' => TRUE,

				  	'#collapsed' => TRUE,

					//'#prefix' => '<table>',

		  			//'#suffix' => '</table>',	

				  	'#tree' => TRUE,

  		);

			foreach($view_data as $dwca_filename_inner => $view_data_inner){

				$views[$dwca_filename][$dwca_filename_inner] = array(

									  	'#type' => 'textfield',

									  	'#title' => t($dwca_filename . '_' . $dwca_filename_inner),

									  	'#default_value' => $view_data_inner['view_name'],

									  	'#size' => 60,

									  	'#description' => t('specify view for ' . $dwca_filename_inner),

									//'#prefix' => '<tr>',

								    //'#suffix' => '</tr>',

				);

				//TODO: Change collaped discription form to table, layout using <td> and <tr> e.g. try 3 description types per row

			}

		} else {

			$views[$dwca_filename] = array(

					  	'#type' => 'textfield',

					  	'#title' => t($dwca_filename),

					  	'#default_value' => $view_data['view_name'],

					  	'#size' => 60,

					  	'#description' => t('specify view for ' . $dwca_filename),

			);

		}

	}

	return $views;

}

function dwca_export_config_form_submit($form, &$form_state) {

	$variables = $form_state['input'];

	$save_variables = '';

	$dwca_export_archive_descriptor_file_map = variable_get(FILE_MAP);

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

		if (array_key_exists($key, $dwca_export_archive_descriptor_file_map)) {

			$dwca_export_archive_descriptor_file_map[$key]['view_name'] = $value;

			//$save_variables .= '<p>' . $key . ' ' . $value . '</p>';

		} else {

			$description_key = 'description';

			if (array_key_exists($description_key, $dwca_export_archive_descriptor_file_map)) {

				//get the inner array containing the different description data types

				$description_map = $dwca_export_archive_descriptor_file_map[$description_key];

				if (array_key_exists($key, $description_map)) {

					//drupal_set_message(t('The ooKEY is... ') . $key . t('The ooVALUE is... ') . $value);

					$dwca_export_archive_descriptor_file_map[$description_key][$key]['view_name'] = $value;

				}

			}

		}

	}

	variable_del(FILE_MAP);

	variable_set(FILE_MAP, $dwca_export_archive_descriptor_file_map);

	//drupal_set_message(t('The classification view is ') . $save_variables);// . '<pre>' . print_r($form_state,true) . '</pre>');//$save_variables);

}

// Reports an error if view name entered by the user does not exist in the database.

function dwca_export_config_form_validate($form, &$form_state) {

	$variables = $form_state['input'];

	$dwca_export_archive_descriptor_file_map = variable_get(FILE_MAP);

	$view_names = array();

	$missing_view_names = '';

	$missing_view = false;

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

		//TODO: Check whether the views for the inner array cotaining all the description views exist

		if (array_key_exists($key, $dwca_export_archive_descriptor_file_map)) {

			$view = views_get_view($value);

			// check whether there is a view named with this value 

			if(!$view) {

				$view_names[] = $value;

				$missing_view_names .= $value . ', ';

				$missing_view = true;

			}

		}

	}

	if ($missing_view) {

		form_set_error('', t('VIEW(S) ' . $missing_view_names . ' NOT FOUND. Please input another view name.'));

	}

}

/**

 * menu callback

 */

function dwca_export_deliver_archive() {

	$tmp_archive_file_name = dwca_export_create_archive( _dwca_export_archive_descriptor_file_map() );

	if($tmp_archive_file_name && file_valid_uri($tmp_archive_file_name)){

		file_transfer($tmp_archive_file_name, array('Content-Type' => 'application/zip'));

	} else {

		throw new Exception(t('Error creating the archive'));

	}

}

/**

 * Provides the archive_descriptor_file_map which maps dwca file name to a set of view information.

 * The view information contains the fields 'view_name', 'display_id', 'out_file_url'.

 * The 'out_file_url' is initailly empty and will be set when this function is called

 * with both parameters.

 *

 * @param String $file_name

 * @param String $out_file_url

 *

 * @return the archive_descriptor_file_map

 */

function _dwca_export_archive_descriptor_file_map($file_name = NULL, $out_file_url = null){

	static $file_map;

	if(!isset($file_map)){

		$file_map = variable_get(FILE_MAP);

	}

	if($file_name && $out_file_url){

		if (in_array($file_name, dwca_export_view_names_array())) {

			$file_map[$file_name]['out_file_url'] = $out_file_url;

		} else {

			$file_map['description'][$file_name]['out_file_url'] = $out_file_url;

		}

	}

	return $file_map;

}

/**

 * Walks all view export paths defined in the $views_map.

 * Each file is downloaded to the tmp folder and a zip file

 * is bundeled of the resulting csv files plus the meta file.

 *

 * @param $views_map - maps a view paths to dwca filenames

 *

 * @return the path in the filesystem to the final archive,

 * or FALSE in case of an error.

 */

function dwca_export_create_archive($views_map) {

	// all data is exported to temporary://dwca_export_*

	// now we can start bundling the actual archive

	$tmp_archive_file_name = drupal_tempnam("temporary://", "dwca_export_archive_");

	// Unfortunately we cannot use drupals ArchiverZip because there ís

	// no way to pass in ZipArchive::CREATE to the constructor to create the archive

	// TODO test if zip functionality is available (i.e. if(function_exists('zip_open'))

	// but I don't know where the proper location for such a check would be

	$zip = new ZipArchive();

	// it is safe to use drupal_realpath as the tmp file will be certainly local

	// and php's ZipArchive does not handle stream URIs

	$result = $zip->open(drupal_realpath($tmp_archive_file_name), ZipArchive::CREATE);

	// there might be a better way to get at this information

	$module_static_dir_absolute_path = realpath(drupal_get_path('module', 'dwca_export')) . STATIC_DIR;

	if ($result !== TRUE) {

		throw new Exception(t('Could not create zip_archive %tmp_archive_file_name', array('%tmp_archive_file_name' => $tmp_archive_file_name)));

	}

	// add metadata

	$zip->addFile($module_static_dir_absolute_path.METADATA_FILE_NAME, ARCHIVE_ROOT_DIR.METADATA_FILE_NAME);

	global $base_url;

	// execute all views to export the data into

	// temporary csv files (temporary://dwca_export_*). the resulting filenames

	// will be stored in _dwca_export_archive_descriptor_file_map()

	foreach($views_map as $filename=>$view_data){

		//lorna

		if ($filename == 'description') {

			//lorna: this foreach iterates through all the description types in the inner array

			foreach($view_data as $filename_inner => $view_data_inner){

				$view = views_get_view($view_data_inner['view_name']);

				$options = array (

					'output_file' => $filename_inner

				);

				_dwca_export_views_data_export_override_batch($view, $view_data_inner['display_id'], $options);

				if ($view) {

					$view->execute_display($view_data_inner['display_id']);

				}else{

					throw new Exception(t('A view with the name %view does not exist', array('%view' => $view_data_inner['view_name'])));

				}

			}

		}

		else {

			$view = views_get_view($view_data['view_name']);

			$options = array (

					    'output_file' => $filename

			);

			_dwca_export_views_data_export_override_batch($view, $view_data['display_id'], $options);

			if ($view) {

				$view->execute_display($view_data['display_id']);

			} else{

				throw new Exception(t('A view with the name %view does not exist', array('%view' => $view_data['view_name'])));

			}

		}

		//end lorna

	}

	// add the csv data files

	foreach(_dwca_export_archive_descriptor_file_map() as $dwca_filename=>$view_data){

		if ($dwca_filename == 'description') {

			_dwca_export_concatenate_description_files($view_data, $zip);

		} else {

			$view_temp_file = $view_data['out_file_url'];

			_dwca_export_add_files_to_zip($view_temp_file, $dwca_filename, $zip);

		}

	}

	$zip->close();

	return $tmp_archive_file_name;

}

/**

 * 

 * Combines multiple Description Views for different description types into a single text file

 * @param $view_data The inner array containing the view data for the different description types

 * @param $zip The zip file for the files making up the DwC-A.

 */

function _dwca_export_concatenate_description_files($view_data, $zip){

	$desc_file_name = drupal_tempnam("temporary://", "description.tmp");

	$desc_file = fopen(drupal_realpath($desc_file_name), "w");	

	foreach($view_data as $type=>$view_data_inner){

		$view_temp_file = $view_data_inner['out_file_url'];

		$descTypeFile = fopen($view_temp_file, "r");

		while(!feof($descTypeFile)){

			$lineOfText = fgets($descTypeFile, 4096);

			$items = explode(',', $lineOfText);

			//don't include empty descriptions or lines at the end of the view which start with the field name id

			//some lines just contain a single " if there is a carriage return within the description text so remove these too

			if (isset($items[0]) && isset($items[2])) {

				if ($items[0]!=="\"id\""  && trim($items[2])!=="\"\"") {

					// fix conflict with files that have an EOL that differs from the server EOL

					$lineOfText = rtrim($lineOfText, "\r\n") . PHP_EOL;

					fwrite($desc_file, $lineOfText);

				}	

			} else {

				fgets($descTypeFile, 4096);

			}

		}

		fclose($descTypeFile);

	}

	fclose($desc_file);

	_dwca_export_add_files_to_zip($desc_file_name, 'description', $zip);

}

function _dwca_export_add_files_to_zip($view_temp_file = NULL, $dwca_filename, $zip){

	if($view_temp_file){

		$zip->addFile(drupal_realpath($view_temp_file), ARCHIVE_ROOT_DIR.$dwca_filename . FILE_EXTENSION);

	}else{

		throw new Exception(t('Cannot create %file', array('%file' => $dwca_filename)));

	}

}

/**

 * Helper function that indicates that we want to

 * override the batch that the views_data_export view creates

 * on it's initial time through.

 *

 * Also provides a place to stash options that need to stay around

 * until the end of the batch

 *

 * adapted fom views_data_export.drush.inc

 */

function _dwca_export_views_data_export_override_batch($view = NULL, $display = NULL, $options = TRUE) {

	static $_views;

	if (isset($view)) {

		$_views[$view->name][$display] = $options;

	}

	return $_views;

}

/**

 * Implementation of hook_views_data_export_batch_alter()

 *

 * adapted fom views_data_export.drush.inc

 *

 *  @see batch_process() in form.inc

 */

function dwca_export_views_data_export_batch_alter(&$batch, &$final_destination, &$querystring) {

	$view_name = $batch['view_name'];

	$display_id = $batch['display_id'];

	$ok_to_override = _dwca_export_views_data_export_override_batch();

	// Make sure we do nothing if we are called not following the execution of

	// our drush command. This could happen if the file with this function in it

	// is included during the normal execution of the view

	if (!$ok_to_override[$view_name][$display_id]) {

		return;

	}

	$options = $ok_to_override[$view_name][$display_id];

	// We actually never return from the drupal_alter, but

	// use drush's batch system to run the same batch

	// Add a final callback

	$batch['operations'][] = array(

	    '_dwca_export_views_data_export_batch_finished', array($batch['eid'], $options['output_file']),

	);

	$batch['progressive'] = FALSE;

}

/**

* Implementation of hook_views_data_export_batch_alter()

*

* @see batch_process() in form.inc

*/

function dwca_export_batch_alter(&$batch, &$final_destination, &$querystring) {

	if($batch['source_url'] == 'dwca_export'){

		$batch['progressive'] = FALSE;

	}

}

/**

* Get's called at the end of the drush batch process that generated our export

*

* adapted fom views_data_export.drush.inc

*/

function _dwca_export_views_data_export_batch_finished($eid, $output_file, &$context) {

	// Fetch export info

	$export = views_data_export_get($eid);

	// Perform cleanup

	$view = views_data_export_view_retrieve($eid);

	$view->set_display($export->view_display_id);

	$view->display_handler->batched_execution_state = $export;

	$view->display_handler->remove_index();

	// Get path to temp file

	$temp_file = $view->display_handler->outputfile_path();

	_dwca_export_archive_descriptor_file_map($output_file, $temp_file);

}

function dwca_export_permission() {

	return array(

    'administer dwca-export' => array(

      'title' => t('Access dwca-export'),

      'description' => t('Allows user to access DwC-A export configuration page and execute export of the DwC-A data.'),

	));

}