FIX DateField Calendar - make dates with day- and monthnames validate

In locales other than en_US, as a result of missing jQuery locale
files, the DatePicker defaulted to English whenever day and monthnames
were used, breaking validation. Needed to change official locale files
before adding, because Zend_Date and jQuery day/monthnames not matching
again breaks validation.

Removed hard setting the names to uppercase, breaking validation for
other locales

Changed order in convert_iso_to_jquery_format(), to prevent EEE(E)
settings from being overwritten

Added a check for existing locale files, and made DatePicker fallback
to ISO yyy-MM-dd if a missing locale file would otherwise break
validation.

Added documentation for the DateField

docs/en/reference/datefield.md

@@ -0,0 +1,131 @@
+# DateField
+
+## Introduction
+
+This `FormField` subclass lets you display an editable date, either in 
+a single text input field, or in three separate fields for day, month and year. 
+It also provides a calendar datepicker.
+
+## Adding a DateField 
+
+The following example will add a simple DateField to your Page, allowing you to 
+enter a date manually. 
+
+	:::php
+	class Page extends SiteTree {
+		static $db = array(
+			'MyDate' => 'Date',
+		);
+
+		public function getCMSFields() {
+			$fields = parent::getCMSFields();
+			
+			$fields->addFieldToTab(
+				'Root.Main',
+				$myDate = new DateField('MyDate', 'Enter a date')
+			);
+			
+			return $fields;
+		} 
+	}	
+
+## Custom Dateformat
+
+You can define a custom dateformat for your Datefield based on [Zend_Date constants](http://framework.zend.com/manual/1.12/en/zend.date.constants.html).
+
+	:::php
+	// will display a date in the following format: 31-06-2012
+	DateField::create('MyDate')->setConfig('dateformat', 'dd-MM-yyyy'); 
+
+
+## Min and Max Dates
+
+Set the minimum and maximum allowed datevalues using the `min` and `max` 
+configuration settings (in ISO format or strtotime() compatible). Example: 
+
+	:::php
+	DateField::create('MyDate')
+		->setConfig('min', '-7 days')
+		->setConfig('max', '2012-12-31')
+		
+## Separate Day/Month/Year Fields
+
+The following setting will display your DateField as `three input fields` for 
+day, month and year separately. Any custom dateformat settings will be ignored. 
+HTML5 placeholders 'day', 'month' and 'year' are enabled by default. 
+
+	:::php
+	DateField::create('MyDate')
+		->setConfig('dmyfields', true);
+		->setConfig('dmyseparator', '/') // set the separator
+		->setConfig('dmyplaceholders', 'true'); // enable HTML 5 Placeholders
+
+## Calendar Field
+
+The following setting will add a Calendar to a single DateField, using the 
+`jQuery UI DatePicker widget`
+
+	:::php
+	DateField::create('MyDate')->setConfig('showcalendar', true);
+
+
+### 'Safe' Dateformats to Use with the Calendar
+
+The jQuery DatePicker doesn't support every constant available for Zend_Date. 
+If you choose to use the calendar, the following constants should at least be safe:
+
+Constant | xxxxx
+-------- | -----
+d        | numeric day of the month (without leading zero)
+dd       | numeric day of the month (with leading zero)
+EEE      | dayname, abbreviated
+EEEE     | dayname
+M        | numeric month of the year (without leading zero)
+MM       | numeric month of the year (with leading zero)
+MMM	     | monthname, abbreviated	
+MMMM     | monthname
+y        | year (4 digits)
+yy       | year (2 digits)
+yyyy     | year (4 digits)
+
+### Calendar localization issues
+
+Unfortunately the day- and monthname values in Zend Date do not always match 
+those in the existing jQuery UI locale files, so constants like `EEE` or `MMM`, 
+for day and monthnames could break validation. To fix this we had to slightly 
+alter the jQuery locale files, situated in 
+*/framework/thirdparty/jquery-ui/datepicker/i18n/*, to match Zend_Date. 
+
+At this moment not all locale files may be present. If a locale file is 
+missing, the DatePicker calendar will fallback to 'yyyy-MM-dd' whenever day- 
+and/or monthnames are used. After saving, the correct format will be displayed.  
+
+## Contributing jQuery Locale Files
+
+If you find the jQuery locale file for your chosen locale is missing, the 
+following section will explain how to create one. If you wish to contribute 
+your file to the SilverStripe core, please check out the guide on
+['contributing code'](http://doc.silverstripe.org/framework/en/trunk/misc/contributing/code).
+
+### 1. Get the Sourcefile
+
+You can find a list of locale files for the jQuery UI DatePicker 
+[in the jQuery source code](https://github.com/jquery/jquery-ui/tree/master/ui/i18n).
+
+### 2. Find your Zend Locale File
+
+The Zend locale files are located in */framework/thirdparty/Zend/Locale/Data/*. 
+Find the one that has the information for your locale. 
+
+### 3. Find the Date Values
+
+You're looking for the `Gregorian` date values for monthnames and daynames in 
+the Zend locale file. Edit the DatePicker locale File so your *full day- and 
+monthnames* and *short monthnames* match. For your *short daynames*, use the 
+first three characters of the full name. Note that Zend dates are `case 
+sensitive`!
+
+### 4. Filename
+
+Use the original jQuery UI filename 'jquery.ui.datepicker-xx.js', where xx 
+stands for the locale.

forms/DateField.php

@@ -113,12 +113,26 @@ public function __construct($name, $title = null, $value = null) {
 	}
 
 	public function FieldHolder($properties = array()) {
-		// TODO Replace with properly extensible view helper system 
-		$d = DateField_View_JQuery::create($this); 
-		$d->onBeforeRender(); 
+		if ($this->getConfig('showcalendar')) {
+			// TODO Replace with properly extensible view helper system 
+			$d = DateField_View_JQuery::create($this); 
+			if(!$d->regionalSettingsExist()) {
+				$dateformat = $this->getConfig('dateformat');
+
+				// if no localefile is present, the jQuery DatePicker 
+				// month- and daynames will default to English, so the date
+				// will not pass Zend validatiobn. We provide a fallback  
+				if (preg_match('/(MMM+)|(EEE+)/', $dateformat)) {
+					$this->setConfig('dateformat', $this->getConfig('datavalueformat'));
+				}
+			} 
+			$d->onBeforeRender();
+		}
 		$html = parent::FieldHolder(); 
-		$html = $d->onAfterRender($html); 
-
+
+		if(!empty($d)) {
+			$html = $d->onAfterRender($html); 
+		}	
 		return $html;
 	}
 
@@ -199,9 +213,6 @@ public function setValue($val) {
 			$this->value = null;
 			$this->valueObj = null;
 		} else {
-			// Quick fix for overzealous Zend validation, its case sensitive on month names (see #5990)
-			if(is_string($val)) $val = ucwords(strtolower($val));
-
 			if($this->getConfig('dmyfields')) {
 				// Setting in correct locale
 				if(is_array($val) && $this->validateArrayValue($val)) {
@@ -480,6 +491,11 @@ class DateField_View_JQuery extends Object {
 
 	protected $field;
 
+	/*
+	 * the current jQuery UI DatePicker locale file
+	 */
+	protected $jqueryLocaleFile = '';	
+
 	/**
 	 * @var array Maps values from {@link i18n::$all_locales()} to 
 	 * localizations existing in jQuery UI.
@@ -488,7 +504,7 @@ class DateField_View_JQuery extends Object {
 		'en_GB' => 'en-GB',
 		'en_US' => 'en', 
 		'en_NZ' => 'en-GB', 
-		'fr_CH' => 'fr-CH',
+		'fr_CH' => 'fr',
 		'pt_BR' => 'pt-BR',
 		'sr_SR' => 'sr-SR',
 		'zh_CN' => 'zh-CN',
@@ -509,7 +525,24 @@ public function __construct($field) {
 	public function getField() {
 		return $this->field;
 	}
-
+
+	/**
+	 * Check if jQuery UI locale settings exists for the current locale
+	 * @return boolean
+	 */
+	function regionalSettingsExist() {
+		$lang = $this->getLang();
+		$localeFile = THIRDPARTY_DIR . "/jquery-ui/datepicker/i18n/jquery.ui.datepicker-{$lang}.js";
+		if (file_exists(Director::baseFolder() . '/' .$localeFile)){
+			$this->jqueryLocaleFile = $localeFile;
+			return true;
+		} else { 
+			// file goes before internal en_US settings,
+			// but both will validate  
+			return ($lang == 'en'); 
+		}
+	}	
+
 	public function onBeforeRender() {
 	}
 
@@ -524,16 +557,9 @@ public function onAfterRender($html) {
 			Requirements::javascript(FRAMEWORK_DIR . '/thirdparty/jquery-ui/jquery-ui.js');
 
 			// Include language files (if required)
-			$lang = $this->getLang();
-			if($lang != 'en') {
-				// TODO Check for existence of locale to avoid unnecessary 404s from the CDN
-				Requirements::javascript(
-					sprintf(
-						THIRDPARTY_DIR . '/jquery-ui/minified/i18n/jquery.ui.datepicker-%s.min.js',
-						// can be a mix between names (e.g. 'de') and combined locales (e.g. 'zh-TW')
-						$lang
-					));
-			}
+			if ($this->jqueryLocaleFile){
+				Requirements::javascript($this->jqueryLocaleFile);
+ 			}
 
 			Requirements::javascript(FRAMEWORK_DIR . "/javascript/DateField.js");
 		}
@@ -578,12 +604,12 @@ public static function convert_iso_to_jquery_format($format) {
 		  '/^d([^d])/' => 'd$1',
 		  '/([^d])d$/' => '$1d',
 		  '/dd/' => 'dd',
-		  '/EEEE/' => 'DD',
-		  '/EEE/' => 'D',
 		  '/SS/' => '',
 		  '/eee/' => 'd',
 		  '/e/' => 'N',
 		  '/D/' => '',
+		  '/EEEE/' => 'DD',
+		  '/EEE/' => 'D', 
 		  '/w/' => '',
 			// make single "M" lowercase
 		  '/([^M])M([^M])/' => '$1m$2',

thirdparty/jquery-ui/datepicker/i18n/README

@@ -0,0 +1,25 @@
+AUTHOR: Martine Bloem (http://www.balbuss.com)
+**********************************************
+
+jQuery UI DatePicker localization files for SilverStripe 3.0
+------------------------------------------------------------
+These files are adaptations of the official localization files that can be found here:
+http://jquery-ui.googlecode.com/svn/trunk/ui/i18n/
+
+Day- and monthnames have been changed to match the values Zend Date uses, to make 
+the following dateformats validate:
+
+EEE:  weekday short
+EEEE: weekday
+MMM:  monthname short
+MMMM: monthname
+
+For locales for which no file exists (yet), the DatePicker will revert to a numeric 
+format, that will validate, and after being saved will be displayed in the 
+required format.
+
+To create your own language fiel, download the original file from the URL above, 
+find the Zend Date locale file in framework/Zend/Locale/Data and make sure that
+
+- monthNames, monthNamesShort and dayNames are equivalent to Zend (Gregorian) names 
+- dayNamesShort should be the first 3 characters of dayNames

thirdparty/jquery-ui/datepicker/i18n/jquery.ui.datepicker-da.js

@@ -0,0 +1,25 @@
+/*
+ * Danish (UTF-8) initialisation for the jQuery UI date picker plugin.
+ * Adapted to match the Zend Data localization for SilverStripe CMS
+ * See: README
+ */
+jQuery(function($){
+    $.datepicker.regional['da'] = {
+		closeText: 'Luk',
+        prevText: '<Forrige',
+		nextText: 'Næste>',
+		currentText: 'Idag',
+        monthNames: ['januar','februar','marts','april','maj','juni','juli','august','september','oktober','november','december'],
+        monthNamesShort: ['jan.','feb.','mar.','apr.','maj','jun.','jul.','aug.','sep.','okt.','nov.','dec.'],
+		dayNames: ['søndag','mandag','tirsdag','onsdag','torsdag','fredag','lørdag'],
+		dayNamesShort: ['søn','man','tir','ons','tor','fre','lør'],
+		dayNamesMin: ['Sø','Ma','Ti','On','To','Fr','Lø'],
+		weekHeader: 'Uge',
+        dateFormat: 'dd-mm-yy',
+		firstDay: 1,
+		isRTL: false,
+		showMonthAfterYear: false,
+		yearSuffix: ''};
+    $.datepicker.setDefaults($.datepicker.regional['da']);
+});
+

thirdparty/jquery-ui/datepicker/i18n/jquery.ui.datepicker-de.js

@@ -0,0 +1,25 @@
+/*
+ * German (UTF-8) initialisation for the jQuery UI date picker plugin.
+ * Adapted to match the Zend Data localization for SilverStripe CMS
+ * See: README
+ */
+jQuery(function($){
+	$.datepicker.regional['de'] = {
+		closeText: 'schließen',
+		prevText: '<zurück',
+		nextText: 'Vor>',
+		currentText: 'heute',
+		monthNames: ['Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'],
+		monthNamesShort: ['Jan','Feb','Mär','Apr','Mai','Jun','Jul','Aug','Sep','Okt','Nov','Dez'],
+		dayNames: ['Sonntag','Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag'],
+		dayNamesShort: ['Son','Mon','Die','Mit','Don','Fre','Sam'],
+		dayNamesMin: ['So','Mo','Di','Mi','Do','Fr','Sa'],
+		weekHeader: 'Wo',
+		dateFormat: 'dd.mm.yy',
+		firstDay: 1,
+		isRTL: false,
+		showMonthAfterYear: false,
+		yearSuffix: ''};
+	$.datepicker.setDefaults($.datepicker.regional['de']);
+});
+

thirdparty/jquery-ui/datepicker/i18n/jquery.ui.datepicker-en-GB.js

@@ -0,0 +1,24 @@
+/*
+ * English/UK (UTF-8) initialisation for the jQuery UI date picker plugin.
+ * Adapted to match the Zend Data localization for SilverStripe CMS
+ * See: README
+ */
+jQuery(function($){
+	$.datepicker.regional['en-GB'] = {
+		closeText: 'Done',
+		prevText: 'Prev',
+		nextText: 'Next',
+		currentText: 'Today',
+		monthNames: ['January','February','March','April','May','June','July','August','September','October','November','December'], 
+		monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'], 
+		dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], 
+		dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'], 
+		dayNamesMin: ['Su','Mo','Tu','We','Th','Fr','Sa'],
+		weekHeader: 'Wk',
+		dateFormat: 'dd/mm/yy',
+		firstDay: 1,
+		isRTL: false,
+		showMonthAfterYear: false,
+		yearSuffix: ''};
+	$.datepicker.setDefaults($.datepicker.regional['en-GB']);
+});

thirdparty/jquery-ui/datepicker/i18n/jquery.ui.datepicker-en.js

@@ -0,0 +1,25 @@
+/*
+ * English (UTF-8) initialisation for the jQuery UI date picker plugin.
+ * Adapted to match the Zend Data localization for SilverStripe CMS
+ * See: README
+ */
+jQuery(function($){
+	$.datepicker.regional['en'] = {
+		closeText: 'Done',
+		prevText: 'Prev',
+		nextText: 'Next',
+		currentText: 'Today',
+		monthNames: ['January','February','March','April','May','June','July','August','September','October','November','December'], // For formatting
+		monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'], // For formatting
+		dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], // For formatting
+		dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'], // For formatting
+		dayNamesMin: ['Su','Mo','Tu','We','Th','Fr','Sa'],
+		weekHeader: 'Wk',
+		dateFormat: 'mm/dd/yy',
+		firstDay: 0,
+		isRTL: false,
+		showMonthAfterYear: false,
+		yearSuffix: ''
+	$.datepicker.setDefaults($.datepicker.regional['en']);
+});
+