FEATURE: Allow Text/Varchar fields to be configured to differentiate between NULL and empty string. (#4178, petebd)

git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@90036 467b73ca-7a2a-4603-9d3b-597d59a354a9

core/model/DataObject.php

@@ -3419,6 +3419,21 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		return $entities;
 	}
 	
+	/**
+ 	 * Returns true if the given method/parameter has a value
+ 	 * (Uses the DBField::hasValue if the parameter is a database field)
+ 	 * @param string $funcName The function name.
+ 	 * @param array $args The arguments.
+ 	 * @return boolean
+ 	 */
+ 	function hasValue($funcName, $args = null) {
+ 		$field = $this->dbObject($funcName);
+ 		if ( $field ) {
+ 			return $field->hasValue();
+ 		} else {
+ 			return parent::hasValue($funcName, $args);
+ 		}
+ 	}	
 }
 
 ?>

core/model/fieldtypes/StringField.php

@@ -0,0 +1,79 @@
+<?php
+/**
+ * An abstract base class for the string field types (i.e. Varchar and Text)
+ * @package silverstripe
+ * @subpackage model
+ * @author Pete Bacon Darwin
+ *
+ */
+abstract class StringField extends DBField {
+	protected $nullifyEmpty = true;
+
+	/**
+	 * Construct a string type field with a set of optional parameters
+	 * @param $name string The name of the field
+	 * @param $options array An array of options e.g. array('nullifyEmpty'=>false).  See {@link StringField::setOptions()} for information on the available options
+	 * @return unknown_type
+	 */
+	function __construct($name = null, $options = array()) {
+		// Workaround: The singleton pattern calls this constructor with true/1 as the second parameter, so we must ignore it
+		if(is_array($options)){
+			$this->setOptions($options);
+		}
+		parent::__construct($name);
+	}
+	
+	/**
+	 * Update the optional parameters for this field.
+	 * @param $options array of options
+	 * The options allowed are:
+	 *   <ul><li>"nullifyEmpty"
+	 *       This is a boolean flag.
+	 *       True (the default) means that empty strings are automatically converted to nulls to be stored in the database.
+	 *       Set it to false to ensure that nulls and empty strings are kept intact in the database.
+	 *   </li></ul>
+	 * @return unknown_type
+	 */
+	function setOptions(array $options = array()) {
+		if(array_key_exists("nullifyEmpty", $options)) {
+			$this->nullifyEmpty = $options["nullifyEmpty"] ? true : false;
+		}
+	}
+	
+	/**
+	 * Set whether this field stores empty strings rather than converting them to null
+	 * @param $value boolean True if empty strings are to be converted to null
+	 * @return 
+	 */
+	function setNullifyEmpty($value) {
+		$this->nullifyEmpty == $value ? true : false;
+	}
+	/**
+	 * Get whether this field stores empty strings rather than converting them to null
+	 * @return bool True if empty strings are to be converted to null
+	 */
+	function getNullifyEmpty() {
+		return $this->nullifyEmpty;
+	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see core/model/fieldtypes/DBField#hasValue()
+	 */
+	function hasValue() {
+		return ($this->value || $this->value == '0') || ( !$this->nullifyEmpty && $this->value === '');
+	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see core/model/fieldtypes/DBField#prepValueForDB($value)
+	 */
+	function prepValueForDB($value) {
+		if ( !$this->nullifyEmpty && $value === '' ) {
+			return "'" . Convert::raw2sql($value) . "'";
+		} else {
+			return parent::prepValueForDB($value);
+		}
+	}
+
+}

core/model/fieldtypes/Text.php

@@ -4,21 +4,21 @@
  * @package sapphire
  * @subpackage model
  */
-class Text extends DBField {
+class Text extends StringField {
 	static $casting = array(
 		"AbsoluteLinks" => "HTMLText",
 	);
 	
+ 	/**
+ 	 * (non-PHPdoc)
+ 	 * @see DBField::requireField()
+ 	 */
 	function requireField() {
 		$parts=Array('datatype'=>'mediumtext', 'character set'=>'utf8', 'collate'=>'utf8_general_ci', 'arrayValue'=>$this->arrayValue);
 		$values=Array('type'=>'text', 'parts'=>$parts);
 		DB::requireField($this->tableName, $this->name, $values, $this->default);
 	}
 	
-	function hasValue() {
-		return ($this->value || $this->value == '0');
-	}
-	
 	/**
 	 * Limit this field's content by a number of words.
 	 * CAUTION: This is not XML safe. Please use
@@ -42,13 +42,25 @@ class Text extends DBField {
 		return $ret;
 	}
 	
+	/**
+	 * Return the value of the field stripped of html tags
+	 * @return string
+	 */
 	function NoHTML() {
 		return strip_tags($this->value);
 	}
+	/**
+	 * Return the value of the field with XML tags escaped.
+	 * @return string
+	 */
 	function EscapeXML() {
 		return str_replace(array('&','<','>','"'), array('&amp;','&lt;','&gt;','&quot;'), $this->value);
 	}
 	
+	/**
+	 * Return the value of the field with relative links converted to absolute urls.
+	 * @return string
+	 */
 	function AbsoluteLinks() {
 		return HTTP::absoluteURLs($this->value);
 	}
@@ -292,13 +304,26 @@ class Text extends DBField {
 		}
 	}
 	
+	/**
+	 * (non-PHPdoc)
+	 * @see DBField::scaffoldFormField()
+	 */
 	public function scaffoldFormField($title = null, $params = null) {
-		return new TextareaField($this->name, $title);
+		if($this->nullifyEmpty) {
+			// We can have an empty field so we need to let the user specifically set null value in the field.
+			return new NullableField(new TextareaField($this->name, $title));
+		} else {
+			return new TextareaField($this->name, $title);
+		}
 	}
 	
+	/**
+	 * (non-PHPdoc)
+	 * @see DBField::scaffoldSearchField()
+	 */
 	public function scaffoldSearchField($title = null, $params = null) {
 		return new TextField($this->name, $title);
 	}
 }
 
-?>
+?>

core/model/fieldtypes/Varchar.php

@@ -4,30 +4,48 @@
  * @package sapphire
  * @subpackage model
  */
-class Varchar extends DBField {
+class Varchar extends StringField {
 	
 	protected $size;
-	
-	function __construct($name, $size = 50) {
+	 
+ 	/**
+ 	 * Construct a new short text field
+ 	 * @param $name string The name of the field
+ 	 * @param $size int The maximum size of the field, in terms of characters
+ 	 * @param $options array Optional parameters, e.g. array("nullifyEmpty"=>false). See {@link StringField::setOptions()} for information on the available options
+ 	 * @return unknown_type
+ 	 */
+ 	function __construct($name, $size = 50, $options = array()) {
 		$this->size = $size ? $size : 50;
-		parent::__construct($name);
+		parent::__construct($name, $options);
 	}
 	
+ 	/**
+ 	 * (non-PHPdoc)
+ 	 * @see DBField::requireField()
+ 	 */
 	function requireField() {
-		$parts=Array('datatype'=>'varchar', 'precision'=>$this->size, 'character set'=>'utf8', 'collate'=>'utf8_general_ci', 'arrayValue'=>$this->arrayValue);
-		$values=Array('type'=>'varchar', 'parts'=>$parts);
+		$parts = array(
+			'datatype'=>'varchar',
+			'precision'=>$this->size,
+			'character set'=>'utf8',
+			'collate'=>'utf8_general_ci',
+			'arrayValue'=>$this->arrayValue
+		);
+		
+		$values = array(
+			'type' => 'varchar',
+			'parts' => $parts
+		);
+			
 		DB::requireField($this->tableName, $this->name, $values);
 	}
 	
-	function hasValue() {
-		return ($this->value || $this->value == '0');
-	}
-	
 	/**
 	 * Return the first letter of the string followed by a .
 	 */
 	function Initial() {
-		if($this->value) return $this->value[0] . '.';
+		if($this->hasValue()) return $this->value[0] . '.';
 	}
 	
 	/**
@@ -37,15 +55,38 @@ class Varchar extends DBField {
 		if(ereg('^[a-zA-Z]+://', $this->value)) return $this->value;
 		else return "http://" . $this->value;
 	}
-	
+
+	/**
+	 * Return the value of the field in rich text format
+	 * @return string
+	 */
 	function RTF() {
 		return str_replace("\n", '\par ', $this->value);
 	}
-	
+
+	/**
+	 * Returns the value of the string, limited to the specified number of characters
+	 * @param $limit int Character limit
+	 * @param $add string Extra string to add to the end of the limited string
+	 * @return string
+	 */
 	function LimitCharacters($limit = 20, $add = "...") {
 		$value = trim($this->value);
 		return (strlen($value) > $limit) ? substr($value, 0, $limit) . $add : $value;
 	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see DBField::scaffoldFormField()
+	 */
+	public function scaffoldFormField($title = null, $params = null) {
+		if ( !$this->nullifyEmpty ) {
+			// We can have an empty field so we need to let the user specifically set null value in the field.
+			return new NullableField(new TextField($this->name, $title));
+		} else {
+			return parent::scaffoldFormField($title);
+		}
+	}
 }
 
-?>
+?>

forms/NullableField.php

@@ -0,0 +1,118 @@
+<?php
+/**
+ * NullableField is a field that wraps other fields when you want to allow the user to specify whether the value of the field is null or not.
+ * 
+ * The classic case is to wrap a TextField so that the user can distinguish between an empty string and a null string.
+ * $a = new NullableField(new TextField("Field1", "Field 1", "abc"));
+ * 
+ * It displays the field that is wrapped followed by a checkbox that is used to specify if the value is null or not.
+ * It uses the Title of the wrapped field for its title.
+ * When a form is submitted the field tests the value of the "is null" checkbox and sets its value accordingly.
+ * You can retrieve the value of the wrapped field from the NullableField as follows:
+ * $field->Value() or $field->dataValue()
+ * 
+ * You can specify the label to use for the "is null" checkbox.  If you want to use I8N for this label then specify it like this:
+ * $field->setIsNullLabel(_T(SOME_MODULE_ISNULL_LABEL, "Is Null");
+ * 
+ * @author Pete Bacon Darwin
+ *
+ */
+class NullableField extends FormField {
+	/**
+	 * The field that holds the value of this field
+	 * @var FormField
+	 */
+	protected $valueField;
+		
+	/**
+	 * The label to show next to the is null check box.
+	 * @var string
+	 */
+	protected $isNullLabel;
+	
+
+	/**
+	 * Create a new nullable field
+	 * @param $valueField
+	 * @return NullableField
+	 */
+	function __construct(FormField $valueField, $isNullLabel = null) {
+		$this->valueField = $valueField;
+		$this->isNullLabel = $isNullLabel;
+		if ( is_null($this->isNullLabel) ) {
+			// Set a default label if one is not provided.
+			$this->isNullLabel = _t('NullableField.IsNullLabel', 'Is Null', PR_HIGH);
+		}
+		parent::__construct($valueField->Name(), $valueField->Title(), $valueField->Value(), $valueField->getForm(), $valueField->RightTitle());
+		$this->readonly = $valueField->isReadonly();
+	}
+	
+	/**
+	 * Get the label used for the Is Null checkbox.
+	 * @return string
+	 */
+	function getIsNullLabel() {
+		return $this->isNullLabel;
+	}
+	/**
+	 * Set the label used for the Is Null checkbox.
+	 * @param $isNulLabel string
+	 * @return 
+	 */
+	function setIsNullLabel(string $isNulLabel){
+		$this->isNullLabel = $isNulLabel;
+	}
+	
+	/**
+	 * Get the id used for the Is Null check box.
+	 * @return string
+	 */
+	function getIsNullId() {
+		return $this->Name() . "_IsNull";
+	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see sapphire/forms/FormField#Field()
+	 */
+	function Field() {
+		if ( $this->isReadonly()) {
+			$nullableCheckbox = new CheckboxField_Readonly($this->getIsNullId());
+		} else {
+			$nullableCheckbox = new CheckboxField($this->getIsNullId());
+		}
+		$nullableCheckbox->setValue(is_null($this->dataValue()));
+		return $this->valueField->Field() . ' ' . $nullableCheckbox->Field() . '&nbsp;<span>' . $this->getIsNullLabel().'</span>';
+	}
+
+	/**
+	 * Value is sometimes an array, and sometimes a single value, so we need to handle both cases
+	 */
+	function setValue($value, $data = null) {
+		if ( is_array($data) && array_key_exists($this->getIsNullId(), $data) && $data[$this->getIsNullId()] ) {
+			$value = null;
+		}
+		$this->valueField->setValue($value);
+		parent::setValue($value);
+	}
+	
+	/**
+	 * (non-PHPdoc)
+	 * @see forms/FormField#setName($name)
+	 */
+	function setName($name) {
+		// We need to pass through the name change to the underlying value field.
+		$this->valueField->setName($name);
+		parent::setName($name);
+	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see sapphire/forms/FormField#debug()
+	 */
+	function debug() {
+		$result = "$this->class ($this->name: $this->title : <font style='color:red;'>$this->message</font>) = ";
+		$result .= (is_null($this->value)) ? "<<null>>" : $this->value;
+		return result;
+	}
+}

tests/fieldtypes/DBFieldTest.php

@@ -1,5 +1,12 @@
 <?php
 
+/**
+ * 
+ * Tests for DBField objects.
+ * @package sapphire
+ * @subpackage tests
+ *
+ */
 class DBFieldTest extends SapphireTest {
 	
 	/**
@@ -57,6 +64,22 @@ class DBFieldTest extends SapphireTest {
 		$this->assertEquals("'test'", singleton('Varchar')->prepValueForDB('test'));
 		$this->assertEquals("'123'", singleton('Varchar')->prepValueForDB(123));
 
+		/* AllowEmpty Varchar behaviour */
+		$varcharField = new Varchar("testfield", 50, array("nullifyEmpty"=>false));
+		$this->assertSame("'0'", $varcharField->prepValueForDB(0));
+		$this->assertSame("null", $varcharField->prepValueForDB(null));
+		$this->assertSame("null", $varcharField->prepValueForDB(false));
+		$this->assertSame("''", $varcharField->prepValueForDB(''));
+		$this->assertSame("'0'", $varcharField->prepValueForDB('0'));
+		$this->assertSame("'1'", $varcharField->prepValueForDB(1));
+		$this->assertSame("'1'", $varcharField->prepValueForDB(true));
+		$this->assertSame("'1'", $varcharField->prepValueForDB('1'));
+		$this->assertSame("'00000'", $varcharField->prepValueForDB('00000'));
+		$this->assertSame("'0'", $varcharField->prepValueForDB(0000));
+		$this->assertSame("'test'", $varcharField->prepValueForDB('test'));
+		$this->assertSame("'123'", $varcharField->prepValueForDB(123));
+		unset($varcharField);
+		
 		/* Text behaviour */
 		$this->assertEquals("'0'", singleton('Text')->prepValueForDB(0));
 		$this->assertEquals("null", singleton('Text')->prepValueForDB(null));
@@ -70,6 +93,22 @@ class DBFieldTest extends SapphireTest {
 		$this->assertEquals("'0'", singleton('Text')->prepValueForDB(0000));
 		$this->assertEquals("'test'", singleton('Text')->prepValueForDB('test'));
 		$this->assertEquals("'123'", singleton('Text')->prepValueForDB(123));
+
+		/* AllowEmpty Text behaviour */
+		$textField = new Text("testfield", array("nullifyEmpty"=>false));
+		$this->assertSame("'0'", $textField->prepValueForDB(0));
+		$this->assertSame("null", $textField->prepValueForDB(null));
+		$this->assertSame("null", $textField->prepValueForDB(false));
+		$this->assertSame("''", $textField->prepValueForDB(''));
+		$this->assertSame("'0'", $textField->prepValueForDB('0'));
+		$this->assertSame("'1'", $textField->prepValueForDB(1));
+		$this->assertSame("'1'", $textField->prepValueForDB(true));
+		$this->assertSame("'1'", $textField->prepValueForDB('1'));
+		$this->assertSame("'00000'", $textField->prepValueForDB('00000'));
+ 		$this->assertSame("'0'", $textField->prepValueForDB(0000));
+		$this->assertSame("'test'", $textField->prepValueForDB('test'));
+		$this->assertSame("'123'", $textField->prepValueForDB(123));
+		unset($textField);
 		
 		/* Time behaviour */
 		$time = singleton('Time');
@@ -91,9 +130,45 @@ class DBFieldTest extends SapphireTest {
 		$this->assertEquals("00:00:00", $time->getValue());
 		$time->setValue('00:00:00');
 		$this->assertEquals("00:00:00", $time->getValue());
-
 	}
 	
+	function testHasValue() {
+		$varcharField = new Varchar("testfield");
+		$this->assertTrue($varcharField->getNullifyEmpty());
+		$varcharField->setValue('abc');
+		$this->assertTrue($varcharField->hasValue());
+		$varcharField->setValue('');
+		$this->assertFalse($varcharField->hasValue());
+		$varcharField->setValue(null);
+		$this->assertFalse($varcharField->hasValue());
+		
+		$varcharField = new Varchar("testfield", 50, array('nullifyEmpty'=>false));
+		$this->assertFalse($varcharField->getNullifyEmpty());
+		$varcharField->setValue('abc');
+		$this->assertTrue($varcharField->hasValue());
+		$varcharField->setValue('');
+		$this->assertTrue($varcharField->hasValue());
+		$varcharField->setValue(null);
+		$this->assertFalse($varcharField->hasValue());
+
+		$textField = new Text("testfield");
+		$this->assertTrue($textField->getNullifyEmpty());
+		$textField->setValue('abc');
+		$this->assertTrue($textField->hasValue());
+		$textField->setValue('');
+		$this->assertFalse($textField->hasValue());
+		$textField->setValue(null);
+		$this->assertFalse($textField->hasValue());
+		
+		$textField = new Text("testfield", array('nullifyEmpty'=>false));
+		$this->assertFalse($textField->getNullifyEmpty());
+		$textField->setValue('abc');
+		$this->assertTrue($textField->hasValue());
+		$textField->setValue('');
+		$this->assertTrue($textField->hasValue());
+		$textField->setValue(null);
+		$this->assertFalse($textField->hasValue());
+	}
 }
 
-?>
+?>

tests/forms/FormFieldTest.php

@@ -34,8 +34,11 @@ class FormFieldTest extends SapphireTest {
 			if($constructor->getNumberOfRequiredParameters() > 1) continue;
 			if($fieldClass == 'CompositeField' || is_subclass_of($fieldClass, 'CompositeField')) continue;
 			
-			$instance = new $fieldClass("{$fieldClass}_instance");
-			
+			if ( $fieldClass = 'NullableField' ) {
+				$instance = new $fieldClass(new TextField("{$fieldClass}_instance"));
+			} else {
+				$instance = new $fieldClass("{$fieldClass}_instance");
+			}
 			$isReadonlyBefore = $instance->isReadonly();
 			$readonlyInstance = $instance->performReadonlyTransformation();
 			$this->assertEquals(
@@ -64,8 +67,12 @@ class FormFieldTest extends SapphireTest {
 			if($constructor->getNumberOfRequiredParameters() > 1) continue;
 			if($fieldClass == 'CompositeField' || is_subclass_of($fieldClass, 'CompositeField')) continue;
 			
-			$instance = new $fieldClass("{$fieldClass}_instance");
-			
+			if ( $fieldClass = 'NullableField' ) {
+				$instance = new $fieldClass(new TextField("{$fieldClass}_instance"));
+			} else {
+				$instance = new $fieldClass("{$fieldClass}_instance");
+			}
+						
 			$isDisabledBefore = $instance->isDisabled();
 			$disabledInstance = $instance->performDisabledTransformation();
 			$this->assertEquals(

tests/forms/NullableFieldTests.php

@@ -0,0 +1,124 @@
+<?php
+/**
+ * Tests the NullableField form field class.
+ * @package sapphire
+ * @subpackage tests
+ * @author Pete Bacon Darwin
+ *
+ */
+class NullableFieldTests extends SapphireTest {
+	
+	/**
+	 * Test that the NullableField works when it wraps a TextField containing actual content
+	 */
+	function testWithContent() {
+		$a = new NullableField(new TextField("Field1", "Field 1", "abc"));
+		$this->assertEquals("Field1", $a->Name());
+		$this->assertEquals("Field 1", $a->Title());
+		$this->assertSame("abc", $a->Value());
+		$this->assertSame("abc", $a->dataValue());
+		$field = $a->Field();
+		$this->assertTag(array(
+			'tag'=>'input',
+			'id'=>'Field1',
+			'attributes'=>array('type'=>'text', 'name'=>'Field1', 'value'=>'abc'),
+		), $field);
+		$this->assertTag(array(
+			'tag'=>'input',
+			'id'=>'Field1_IsNull',
+			'attributes'=>array('type'=>'checkbox', 'name'=>'Field1_IsNull', 'value'=>'1'),
+		), $field);
+	}
+	/**
+	 * Test that the NullableField works when it wraps a TextField containing an empty string
+	 */
+	function testWithEmpty() {
+		$a = new NullableField(new TextField("Field1", "Field 1", ""));
+		$this->assertEquals("Field1", $a->Name());
+		$this->assertEquals("Field 1", $a->Title());
+		$this->assertSame("", $a->Value());
+		$this->assertSame("", $a->dataValue());
+		$field = $a->Field();
+		$this->assertTag(array(
+			'tag'=>'input',
+			'id'=>'Field1',
+			'attributes'=>array('type'=>'text', 'name'=>'Field1', 'value'=>''),
+		), $field);
+		$this->assertTag(array(
+			'tag'=>'input',
+			'id'=>'Field1_IsNull',
+			'attributes'=>array('type'=>'checkbox', 'name'=>'Field1_IsNull', 'value'=>'1'),
+		), $field);
+	}
+	/**
+	 * Test that the NullableField works when it wraps a TextField containing a null string
+	 */
+	function testWithNull() {
+		$a = new NullableField(new TextField("Field1", "Field 1", null));
+		$this->assertEquals("Field1", $a->Name());
+		$this->assertEquals("Field 1", $a->Title());
+		$this->assertSame(null, $a->Value());
+		$this->assertSame(null, $a->dataValue());
+		$field = $a->Field();
+		$this->assertTag(array(
+			'tag'=>'input',
+			'id'=>'Field1',
+			'attributes'=>array('type'=>'text', 'name'=>'Field1', 'value'=>''),
+		), $field);
+		$this->assertTag(array(
+			'tag'=>'input',
+			'id'=>'Field1_IsNull',
+			'attributes'=>array('type'=>'checkbox', 'name'=>'Field1_IsNull', 'value'=>'1', 'checked'=>'checked'),
+		), $field);
+		unset($a);
+	}
+	
+	/**
+	 * Test NullableField::setValue works when passed simple values
+	 */
+	function testSetValueSimple() {
+		$a = new NullableField(new TextField("Field1", "Field 1"));
+		$a->setValue("abc");
+		$this->assertSame("abc", $a->dataValue());
+		
+		$a = new NullableField(new TextField("Field1", "Field 1"));
+		$a->setValue(null);
+		$this->assertSame(null, $a->dataValue());
+		
+		$a = new NullableField(new TextField("Field1", "Field 1", "abc"));
+		$a->setValue(null);
+		$this->assertSame(null, $a->dataValue());
+
+		$a = new NullableField(new TextField("Field1", "Field 1", "abc"));
+		$a->setValue("xyz");
+		$this->assertSame("xyz", $a->dataValue());
+		
+		$a = new NullableField(new TextField("Field1", "Field 1"));
+		$a->setValue("");
+		$this->assertSame("", $a->dataValue());
+		
+		$a = new NullableField(new TextField("Field1", "Field 1", "abc"));
+		$a->setValue("");
+		$this->assertSame("", $a->dataValue());
+	}
+	
+	/**
+	 * Test NullableField::setValue works when passed an array values,
+	 * which happens when the form submits.
+	 */
+	function testSetValueArray() {
+		$a = new NullableField(new TextField("Field1", "Field 1"));
+		$a->setValue("abc", array("Field1_IsNull"=>false));
+		$this->assertSame("abc", $a->dataValue());
+
+		$a = new NullableField(new TextField("Field1", "Field 1"));
+		$a->setValue("", array("Field1_IsNull"=>false));
+		$this->assertSame("", $a->dataValue());
+
+		$a = new NullableField(new TextField("Field1", "Field 1"));
+		$a->setValue("", array("Field1_IsNull"=>true));
+		$this->assertSame(null, $a->dataValue());
+	}
+
+}
+