Performance optimization by replacing is_null with === null

app/Mage.php

@@ -298,7 +298,7 @@ public static function objects($key = null)
         if (!self::$_objects) {
             self::$_objects = new Varien_Object_Cache;
         }
-        if (is_null($key)) {
+        if ($key === null) {
             return self::$_objects;
         } else {
             return self::$_objects->load($key);
@@ -730,7 +730,7 @@ public static function isInstalled()
      */
     public static function log($message, $level = null, $file = 'system.log', $forceLog = false)
     {
-        $level = is_null($level) ? Zend_Log::DEBUG : $level;
+        $level = $level === null ? Zend_Log::DEBUG : $level;
         if (empty($file) || $file == 'system.log') {
             $file = 'system.log';
             $key = Mage_Core_Model_Logger::LOGGER_SYSTEM;
@@ -865,7 +865,7 @@ public static function getScriptSystemUrl($folder, $exitIfNot = false)
             }
         }
 
-        if (is_null($baseUrl)) {
+        if ($baseUrl === null) {
             $errorMessage = "Unable detect system directory: $folder";
             if ($exitIfNot) {
                 // exit because of infinity loop

app/code/core/Mage/AdminNotification/Helper/Data.php

@@ -71,7 +71,7 @@ class Mage_AdminNotification_Helper_Data extends Mage_Core_Helper_Abstract
      */
     public function getLatestNotice()
     {
-        if (is_null($this->_latestNotice)) {
+        if ($this->_latestNotice === null) {
             $this->_latestNotice = Mage::getModel('Mage_AdminNotification_Model_Inbox')->loadLatestNotice();
         }
         return $this->_latestNotice;
@@ -85,7 +85,7 @@ public function getLatestNotice()
      */
     public function getUnreadNoticeCount($severity)
     {
-        if (is_null($this->_unreadNoticeCounts)) {
+        if ($this->_unreadNoticeCounts === null) {
             $this->_unreadNoticeCounts = Mage::getModel('Mage_AdminNotification_Model_Inbox')->getNoticeStatus();
         }
         return isset($this->_unreadNoticeCounts[$severity]) ? $this->_unreadNoticeCounts[$severity] : 0;
@@ -99,7 +99,7 @@ public function getUnreadNoticeCount($severity)
      */
     public function getPopupObjectUrl($withExt = false)
     {
-        if (is_null($this->_popupUrl)) {
+        if ($this->_popupUrl === null) {
             $sheme = Mage::app()->getFrontController()->getRequest()->isSecure()
                 ? 'https://'
                 : 'http://';

app/code/core/Mage/AdminNotification/Model/Feed.php

@@ -60,7 +60,7 @@ protected function _construct()
      */
     public function getFeedUrl()
     {
-        if (is_null($this->_feedUrl)) {
+        if ($this->_feedUrl === null) {
             $this->_feedUrl = (Mage::getStoreConfigFlag(self::XML_USE_HTTPS_PATH) ? 'https://' : 'http://')
                 . Mage::getStoreConfig(self::XML_FEED_URL_PATH);
         }

app/code/core/Mage/AdminNotification/Model/Inbox.php

@@ -74,7 +74,7 @@ public function getSeverities($severity = null)
             self::SEVERITY_NOTICE   => Mage::helper('Mage_AdminNotification_Helper_Data')->__('notice'),
         );
 
-        if (!is_null($severity)) {
+        if ($severity !== null) {
             if (isset($severities[$severity])) {
                 return $severities[$severity];
             }

app/code/core/Mage/AdminNotification/Model/Survey.php

@@ -107,7 +107,7 @@ public static function isSurveyViewed()
     public static function saveSurveyViewed($viewed)
     {
         $flagData = self::_getFlagModel()->getFlagData();
-        if (is_null($flagData)) {
+        if ($flagData === null) {
             $flagData = array();
         }
         $flagData = array_merge($flagData, array('survey_viewed' => (bool)$viewed));

app/code/core/Mage/Adminhtml/Block/Catalog/Category/Abstract.php

@@ -81,11 +81,11 @@ public function getStore()
 
     public function getRoot($parentNodeCategory=null, $recursionLevel=3)
     {
-        if (!is_null($parentNodeCategory) && $parentNodeCategory->getId()) {
+        if ($parentNodeCategory !== null && $parentNodeCategory->getId()) {
             return $this->getNode($parentNodeCategory, $recursionLevel);
         }
         $root = Mage::registry('root');
-        if (is_null($root)) {
+        if ($root === null) {
             $storeId = (int) $this->getRequest()->getParam('store');
 
             if ($storeId) {
@@ -191,7 +191,7 @@ public function getEditUrl()
     public function getRootIds()
     {
         $ids = $this->getData('root_ids');
-        if (is_null($ids)) {
+        if ($ids === null) {
             $ids = array();
             foreach (Mage::app()->getGroups() as $store) {
                 $ids[] = $store->getRootCategoryId();

app/code/core/Mage/Adminhtml/Block/Catalog/Category/Tab/General.php

@@ -116,7 +116,7 @@ protected function _getAdditionalElementTypes()
 
     protected function _getParentCategoryOptions($node=null, &$options=array())
     {
-        if (is_null($node)) {
+        if ($node === null) {
             $node = $this->getRoot();
         }
 

app/code/core/Mage/Adminhtml/Block/Catalog/Category/Tab/Product.php

@@ -151,7 +151,7 @@ public function getGridUrl()
     protected function _getSelectedProducts()
     {
         $products = $this->getRequest()->getPost('selected_products');
-        if (is_null($products)) {
+        if ($products === null) {
             $products = $this->getCategory()->getProductsPosition();
             return array_keys($products);
         }

app/code/core/Mage/Adminhtml/Block/Catalog/Category/Tree.php

@@ -90,7 +90,7 @@ public function getCategoryCollection()
     {
         $storeId = $this->getRequest()->getParam('store', $this->_getDefaultStoreId());
         $collection = $this->getData('category_collection');
-        if (is_null($collection)) {
+        if ($collection === null) {
             $collection = Mage::getModel('Mage_Catalog_Model_Category')->getCollection();
 
             /* @var $collection Mage_Catalog_Model_Resource_Category_Collection */
@@ -187,7 +187,7 @@ public function getLoadTreeUrl($expanded=null)
     {
         $params = array('_current'=>true, 'id'=>null,'store'=>null);
         if (
-            (is_null($expanded) && Mage::getSingleton('Mage_Backend_Model_Auth_Session')->getIsTreeWasExpanded())
+            ($expanded === null && Mage::getSingleton('Mage_Backend_Model_Auth_Session')->getIsTreeWasExpanded())
             || $expanded == true) {
             $params['expand_all'] = true;
         }

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Attribute/Set/Main.php

@@ -362,7 +362,7 @@ protected function _getSetId()
     public function getIsCurrentSetDefault()
     {
         $isDefault = $this->getData('is_current_set_default');
-        if (is_null($isDefault)) {
+        if ($isDefault === null) {
             $defaultSetId = Mage::getModel('Mage_Eav_Model_Entity_Type')
                 ->load(Mage::registry('entityType'))
                 ->getDefaultAttributeSetId();

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Composite/Fieldset/Configurable.php

@@ -44,7 +44,7 @@ public function getProduct()
             $this->setData('product', Mage::registry('product'));
         }
         $product = $this->getData('product');
-        if (is_null($product->getTypeInstance()->getStoreFilter($product))) {
+        if ($product->getTypeInstance()->getStoreFilter($product) === null) {
             $product->getTypeInstance()->setStoreFilter(Mage::app()->getStore($product->getStoreId()), $product);
         }
 

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Composite/Fieldset/Grouped.php

@@ -61,7 +61,7 @@ public function getProduct()
             $this->setData('product', Mage::registry('product'));
         }
         $product = $this->getData('product');
-        if (is_null($product->getTypeInstance()->getStoreFilter($product))) {
+        if ( $product->getTypeInstance()->getStoreFilter($product) === null) {
             $product->getTypeInstance()->setStoreFilter(Mage::app()->getStore($product->getStoreId()), $product);
         }
 

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Composite/Fieldset/Options.php

@@ -60,7 +60,7 @@ public function getOptionHtml(Mage_Catalog_Model_Product_Option $option)
         $renderer = $this->getOptionRender(
             $this->getGroupOfOption($option->getType())
         );
-        if (is_null($renderer['renderer'])) {
+        if ($renderer['renderer'] === null) {
             $renderer['renderer'] = $this->getLayout()->createBlock($renderer['block'])
                 ->setTemplate($renderer['template'])
                 ->setSkipJsReloadPrice(1);

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Edit/Tab/Attributes/Create.php

@@ -47,7 +47,7 @@ class Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Attributes_Create extends Ma
      */
     public function getConfig()
     {
-        if (is_null($this->_config)) {
+        if ($this->_config === null) {
            $this->_config = new Varien_Object();
         }
 

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Edit/Tab/Options/Option.php

@@ -237,8 +237,8 @@ public function getOptionValues()
 
                 if ($this->getProduct()->getStoreId() != '0') {
                     $value['checkboxScopeTitle'] = $this->getCheckboxScopeHtml($option->getOptionId(), 'title',
-                        is_null($option->getStoreTitle()));
-                    $value['scopeTitleDisabled'] = is_null($option->getStoreTitle())?'disabled':null;
+                        $option->getStoreTitle() === null);
+                    $value['scopeTitleDisabled'] = $option->getStoreTitle() === null?'disabled':null;
                 }
 
                 if ($option->getGroupByType() == Mage_Catalog_Model_Product_Option::OPTION_GROUP_SELECT) {
@@ -263,15 +263,15 @@ public function getOptionValues()
 
                         if ($this->getProduct()->getStoreId() != '0') {
                             $value['optionValues'][$i]['checkboxScopeTitle'] = $this->getCheckboxScopeHtml(
-                                $_value->getOptionId(), 'title', is_null($_value->getStoreTitle()),
+                                $_value->getOptionId(), 'title', $_value->getStoreTitle() === null,
                                 $_value->getOptionTypeId());
-                            $value['optionValues'][$i]['scopeTitleDisabled'] = is_null($_value->getStoreTitle())
+                            $value['optionValues'][$i]['scopeTitleDisabled'] = $_value->getStoreTitle() === null
                                 ? 'disabled' : null;
                             if ($scope == Mage_Core_Model_Store::PRICE_SCOPE_WEBSITE) {
                                 $value['optionValues'][$i]['checkboxScopePrice'] = $this->getCheckboxScopeHtml(
-                                    $_value->getOptionId(), 'price', is_null($_value->getstorePrice()),
+                                    $_value->getOptionId(), 'price', $_value->getstorePrice() === null,
                                     $_value->getOptionTypeId());
-                                $value['optionValues'][$i]['scopePriceDisabled'] = is_null($_value->getStorePrice())
+                                $value['optionValues'][$i]['scopePriceDisabled'] = $_value->getStorePrice() === null
                                     ? 'disabled' : null;
                             }
                         }
@@ -289,8 +289,8 @@ public function getOptionValues()
                     if ($this->getProduct()->getStoreId() != '0' &&
                         $scope == Mage_Core_Model_Store::PRICE_SCOPE_WEBSITE) {
                         $value['checkboxScopePrice'] = $this->getCheckboxScopeHtml($option->getOptionId(),
-                            'price', is_null($option->getStorePrice()));
-                        $value['scopePriceDisabled'] = is_null($option->getStorePrice())?'disabled':null;
+                            'price', $option->getStorePrice() === null);
+                        $value['scopePriceDisabled'] = $option->getStorePrice() === null?'disabled':null;
                     }
                 }
                 $values[] = new Varien_Object($value);

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Edit/Tab/Price/Group/Abstract.php

@@ -200,7 +200,7 @@ public function isMultiWebsites()
      */
     public function getWebsites()
     {
-        if (!is_null($this->_websites)) {
+        if ($this->_websites !== null) {
             return $this->_websites;
         }
 

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Edit/Tabs.php

@@ -182,7 +182,7 @@ public function getProduct()
      */
     public function getAttributeTabBlock()
     {
-        if (is_null(Mage::helper('Mage_Adminhtml_Helper_Catalog')->getAttributeTabBlock())) {
+        if (Mage::helper('Mage_Adminhtml_Helper_Catalog')->getAttributeTabBlock() === null) {
             return $this->_attributeTabBlock;
         }
         return Mage::helper('Mage_Adminhtml_Helper_Catalog')->getAttributeTabBlock();

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Helper/Form/BaseImage.php

@@ -88,7 +88,7 @@ public function __construct(array $attributes = array())
     public function getDefaultHtml()
     {
         $html = $this->getData('default_html');
-        if (is_null($html)) {
+        if ($html === null) {
             $html = ($this->getNoSpan() === true) ? '' : '<span class="field-row">' . "\n";
             $html .= $this->getLabelHtml();
             $html .= $this->getElementHtml();

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Helper/Form/Msrp/Enabled.php

@@ -40,7 +40,7 @@ class Mage_Adminhtml_Block_Catalog_Product_Helper_Form_Msrp_Enabled extends Vari
      */
     public function getElementHtml()
     {
-        if (is_null($this->getValue())) {
+        if ($this->getValue() === null) {
             $this->setValue(Mage_Catalog_Model_Product_Attribute_Source_Msrp_Type_Enabled::MSRP_ENABLE_USE_CONFIG);
         }
         return parent::getElementHtml();

app/code/core/Mage/Adminhtml/Block/Catalog/Product/Helper/Form/Msrp/Price.php

@@ -40,7 +40,7 @@ class Mage_Adminhtml_Block_Catalog_Product_Helper_Form_Msrp_Price extends Varien
      */
     public function getElementHtml()
     {
-        if (is_null($this->getValue())) {
+        if ($this->getValue() === null) {
             $this->setValue(Mage_Catalog_Model_Product_Attribute_Source_Msrp_Type_Price::TYPE_USE_CONFIG);
         }
         return parent::getElementHtml();

app/code/core/Mage/Adminhtml/Block/Customer/Edit/Tab/Account.php

@@ -241,7 +241,7 @@ protected function _addNewCustomerFormFields($form, $fieldset)
 
             $websites = array();
             foreach (Mage::app()->getWebsites(true) as $website) {
-                $websites[$website->getId()] = !is_null($website->getDefaultStore());
+                $websites[$website->getId()] = $website->getDefaultStore() !== null;
             }
             $prefix = $form->getHtmlIdPrefix();
 

app/code/core/Mage/Adminhtml/Block/Customer/Edit/Tab/Newsletter/Grid/Filter/Status.php

@@ -61,7 +61,7 @@ protected function _getOptions()
 
     public function getCondition()
     {
-        if(is_null($this->getValue())) {
+        if($this->getValue() === null) {
             return null;
         }
 

app/code/core/Mage/Adminhtml/Block/Customer/Edit/Tab/View/Sales.php

@@ -72,7 +72,7 @@ public function _beforeToHtml()
         $this->_groupedCollection = array();
 
         foreach ($this->_collection as $sale) {
-            if (!is_null($sale->getStoreId())) {
+            if ($sale->getStoreId() !== null) {
                 $store      = Mage::app()->getStore($sale->getStoreId());
                 $websiteId  = $store->getWebsiteId();
                 $groupId    = $store->getGroupId();

app/code/core/Mage/Adminhtml/Block/Customer/Form/Element/File.php

@@ -202,7 +202,7 @@ public function getEscapedValue($index = null)
             return false;
         }
         $value = $this->getValue();
-        if (is_array($value) && is_null($index)) {
+        if (is_array($value) && $index === null) {
             $index = 'value';
         }
 

app/code/core/Mage/Adminhtml/Block/Customer/Group/Edit.php

@@ -52,7 +52,7 @@ protected function _construct()
 
     public function getHeaderText()
     {
-        if(!is_null(Mage::registry('current_group')->getId())) {
+        if(Mage::registry('current_group')->getId() !== null) {
             return Mage::helper('Mage_Customer_Helper_Data')->__('Edit Customer Group "%s"', $this->escapeHtml(Mage::registry('current_group')->getCustomerGroupCode()));
         } else {
             return Mage::helper('Mage_Customer_Helper_Data')->__('New Customer Group');

app/code/core/Mage/Adminhtml/Block/Customer/Group/Edit/Form.php

@@ -72,7 +72,7 @@ protected function _prepareLayout()
             )
         );
 
-        if (!is_null($customerGroup->getId())) {
+        if ($customerGroup->getId() !== null) {
             // If edit add id
             $form->addField('id', 'hidden',
                 array(

app/code/core/Mage/Adminhtml/Block/Customer/Sales/Order/Address/Form/Renderer/Vat.php

@@ -50,7 +50,7 @@ class Mage_Adminhtml_Block_Customer_Sales_Order_Address_Form_Renderer_Vat
      */
     public function getValidateButton()
     {
-        if (is_null($this->_validateButton)) {
+        if ($this->_validateButton === null) {
             /** @var $form Varien_Data_Form */
             $form = $this->_element->getForm();
 

app/code/core/Mage/Adminhtml/Block/Dashboard/Bar.php

@@ -93,7 +93,7 @@ public function setCurrency($currency)
      */
     public function getCurrency()
     {
-        if (is_null($this->_currentCurrencyCode)) {
+        if ($this->_currentCurrencyCode === null) {
             if ($this->getRequest()->getParam('store')) {
                 $this->_currentCurrencyCode = Mage::app()->getStore($this->getRequest()->getParam('store'))->getBaseCurrency();
             } else if ($this->getRequest()->getParam('website')){

app/code/core/Mage/Adminhtml/Block/Dashboard/Graph.php

@@ -532,7 +532,7 @@ protected function getHeight()
      */
     protected function _prepareData()
     {
-        if (!is_null($this->getDataHelperName())) {
+        if ($this->getDataHelperName() !== null) {
             $availablePeriods = array_keys($this->helper('Mage_Adminhtml_Helper_Dashboard_Data')->getDatePeriods());
             $period = $this->getRequest()->getParam('period');
             $this->getDataHelper()->setParam('period',

app/code/core/Mage/Adminhtml/Block/Media/Uploader.php

@@ -103,7 +103,7 @@ public function getConfigJson()
      */
     public function getConfig()
     {
-        if(is_null($this->_config)) {
+        if($this->_config === null) {
             $this->_config = new Varien_Object();
         }
 

app/code/core/Mage/Adminhtml/Block/Newsletter/Subscriber.php

@@ -64,7 +64,7 @@ protected function _beforeToHtml()
      */
     public function getQueueCollection()
     {
-        if(is_null($this->_queueCollection)) {
+        if($this->_queueCollection === null) {
             /** @var $this->_queueCollection Mage_Newsletter_Model_Resource_Queue_Collection */
             $this->_queueCollection = Mage::getResourceSingleton('Mage_Newsletter_Model_Resource_Queue_Collection')
                 ->addTemplateInfo()

app/code/core/Mage/Adminhtml/Block/Newsletter/Subscriber/Grid/Filter/Website.php

@@ -45,7 +45,7 @@ protected function _getOptions()
 
     public function getCollection()
     {
-        if(is_null($this->_websiteCollection)) {
+        if($this->_websiteCollection === null) {
             $this->_websiteCollection = Mage::getResourceModel('Mage_Core_Model_Resource_Website_Collection')
                 ->load();
         }