diff --git a/application/menunode.class.inc.php b/application/menunode.class.inc.php
index 60a0edef8..2e71abbc3 100644
--- a/application/menunode.class.inc.php
+++ b/application/menunode.class.inc.php
@@ -5,8 +5,6 @@
  */
 
 use Combodo\iTop\Application\Helper\WebResourcesHelper;
-use Combodo\iTop\Application\UI\Base\Component\Title\Title;
-use Combodo\iTop\Application\UI\Base\Component\Title\TitleUIBlockFactory;
 
 require_once(APPROOT.'/application/utils.inc.php');
 require_once(APPROOT.'/application/template.class.inc.php');
@@ -655,8 +653,7 @@ abstract class MenuNode
 		$this->sMenuId = $sMenuId;
 		$this->iParentIndex = $iParentIndex;
 		$this->aReflectionProperties = array();
-		if (utils::StrLen($sEnableClass) > 0)
-		{
+		if (utils::IsNotNullOrEmptyString($sEnableClass)) {
 			$this->aReflectionProperties['enable_class'] = $sEnableClass;
 			$this->aReflectionProperties['enable_action'] = $iActionCode;
 			$this->aReflectionProperties['enable_permission'] = $iAllowedResults;
diff --git a/application/utils.inc.php b/application/utils.inc.php
index ce2fc43a8..a9a4ce10c 100644
--- a/application/utils.inc.php
+++ b/application/utils.inc.php
@@ -2855,6 +2855,36 @@ HTML;
 		return strlen($sString ?? '');
 	}
 
+	/**
+	 * Helper around the native strlen() PHP method to test a string for null or empty value
+	 *
+	 * @link https://www.php.net/releases/8.1/en.php#deprecations_and_bc_breaks "Passing null to non-nullable internal function parameters is deprecated"
+	 *
+	 * @param string|null $sString
+	 *
+	 * @return boolean if string null or empty
+	 * @since 3.0.2 N°5302
+	 */
+	public static function IsNullOrEmptyString(?string $sString): boolean
+	{
+		return $sString == null || strlen($sString) == 0;
+	}
+
+	/**
+	 * Helper around the native strlen() PHP method to test a string not null or empty value
+	 *
+	 * @link https://www.php.net/releases/8.1/en.php#deprecations_and_bc_breaks "Passing null to non-nullable internal function parameters is deprecated"
+	 *
+	 * @param string|null $sString
+	 *
+	 * @return boolean if string is not null and not empty
+	 * @since 3.0.2 N°5302
+	 */
+	public static function IsNotNullOrEmptyString(?string $sString): boolean
+	{
+		return !static::IsNullOrEmptyString($sString);
+	}
+
 	//----------------------------------------------
 	// Environment helpers
 	//----------------------------------------------
diff --git a/core/metamodel.class.php b/core/metamodel.class.php
index 2d95a5bcd..658774d31 100644
--- a/core/metamodel.class.php
+++ b/core/metamodel.class.php
@@ -461,7 +461,7 @@ abstract class MetaModel
 			$oStyle = self::$m_aClassParams[$sClass]['style'];
 			$sIcon = $oStyle->GetIconAsAbsUrl();
 		}
-		if (utils::StrLen($sIcon) == 0) {
+		if (utils::IsNullOrEmptyString($sIcon)) {
 			$sParentClass = self::GetParentPersistentClass($sClass);
 			if (strlen($sParentClass) > 0) {
 				return self::GetClassIcon($sParentClass, $bImgTag, $sMoreStyles);
@@ -494,7 +494,7 @@ abstract class MetaModel
 			$oStyle = new ormStyle("ibo-class-style--$sClass", "ibo-class-style-alt--$sClass");
 		}
 
-		if ((utils::StrLen($oStyle->GetMainColor()) > 0) && (utils::StrLen($oStyle->GetComplementaryColor()) > 0) && (utils::StrLen($oStyle->GetIconAsRelPath()) > 0)) {
+		if (utils::IsNotNullOrEmptyString($oStyle->GetMainColor()) && utils::IsNotNullOrEmptyString($oStyle->GetComplementaryColor()) && utils::IsNotNullOrEmptyString($oStyle->GetIconAsRelPath())) {
 			// all the parameters are set, no need to search in the parent classes
 			return $oStyle;
 		}
@@ -504,18 +504,18 @@ abstract class MetaModel
 		while (strlen($sParentClass) > 0) {
 			$oParentStyle = self::GetClassStyle($sParentClass);
 			if (!is_null($oParentStyle)) {
-				if (utils::StrLen($oStyle->GetMainColor()) == 0) {
+				if (utils::IsNullOrEmptyString($oStyle->GetMainColor())) {
 					$oStyle->SetMainColor($oParentStyle->GetMainColor());
 					$oStyle->SetStyleClass($oParentStyle->GetStyleClass());
 				}
-				if (utils::StrLen($oStyle->GetComplementaryColor()) == 0) {
+				if (utils::IsNullOrEmptyString($oStyle->GetComplementaryColor())) {
 					$oStyle->SetComplementaryColor($oParentStyle->GetComplementaryColor());
 					$oStyle->SetAltStyleClass($oParentStyle->GetAltStyleClass());
 				}
-				if (utils::StrLen($oStyle->GetIconAsRelPath()) == 0) {
+				if (utils::IsNullOrEmptyString($oStyle->GetIconAsRelPath())) {
 					$oStyle->SetIcon($oParentStyle->GetIconAsRelPath());
 				}
-				if ((utils::StrLen($oStyle->GetMainColor()) > 0) && (utils::StrLen($oStyle->GetComplementaryColor()) > 0) && (utils::StrLen($oStyle->GetIconAsRelPath()) > 0)) {
+				if (utils::IsNotNullOrEmptyString($oStyle->GetMainColor()) && utils::IsNotNullOrEmptyString($oStyle->GetComplementaryColor()) && utils::IsNotNullOrEmptyString($oStyle->GetIconAsRelPath())) {
 					// all the parameters are set, no need to search in the parent classes
 					return $oStyle;
 				}
@@ -523,7 +523,7 @@ abstract class MetaModel
 			$sParentClass = self::GetParentPersistentClass($sParentClass);
 		}
 
-		if ((utils::StrLen($oStyle->GetMainColor()) == 0) && (utils::StrLen($oStyle->GetComplementaryColor()) == 0) && (utils::StrLen($oStyle->GetIconAsRelPath()) == 0)) {
+		if (utils::IsNullOrEmptyString($oStyle->GetMainColor()) && utils::IsNullOrEmptyString($oStyle->GetComplementaryColor()) && utils::IsNullOrEmptyString($oStyle->GetIconAsRelPath())) {
 			return null;
 		}
 
diff --git a/core/ormStyle.class.inc.php b/core/ormStyle.class.inc.php
index 8f3b02abf..dabbd59bd 100644
--- a/core/ormStyle.class.inc.php
+++ b/core/ormStyle.class.inc.php
@@ -50,7 +50,7 @@ class ormStyle
 	 */
 	public function HasMainColor(): bool
 	{
-		return utils::StrLen($this->sMainColor) > 0;
+		return utils::IsNotNullOrEmptyString($this->sMainColor);
 	}
 
 	/**
@@ -68,7 +68,7 @@ class ormStyle
 	 */
 	public function SetMainColor(?string $sMainColor)
 	{
-		$this->sMainColor = (utils::StrLen($sMainColor) === 0) ? null : $sMainColor;
+		$this->sMainColor = utils::IsNullOrEmptyString($sMainColor) ? null : $sMainColor;
 		return $this;
 	}
 
@@ -78,7 +78,7 @@ class ormStyle
 	 */
 	public function HasComplementaryColor(): bool
 	{
-		return utils::StrLen($this->sComplementaryColor) > 0;
+		return utils::IsNotNullOrEmptyString($this->sComplementaryColor);
 	}
 
 	/**
@@ -96,7 +96,7 @@ class ormStyle
 	 */
 	public function SetComplementaryColor(?string $sComplementaryColor)
 	{
-		$this->sComplementaryColor = (utils::StrLen($sComplementaryColor) === 0) ? null : $sComplementaryColor;
+		$this->sComplementaryColor = utils::IsNullOrEmptyString($sComplementaryColor) ? null : $sComplementaryColor;
 		return $this;
 	}
 
@@ -116,7 +116,7 @@ class ormStyle
 	 */
 	public function HasStyleClass(): bool
 	{
-		return utils::StrLen($this->sStyleClass) > 0;
+		return utils::IsNotNullOrEmptyString($this->sStyleClass);
 	}
 
 	/**
@@ -134,7 +134,7 @@ class ormStyle
 	 */
 	public function SetStyleClass(?string $sStyleClass)
 	{
-		$this->sStyleClass = (utils::StrLen($sStyleClass) === 0) ? null : $sStyleClass;
+		$this->sStyleClass = utils::IsNullOrEmptyString($sStyleClass) ? null : $sStyleClass;
 		return $this;
 	}
 
@@ -144,7 +144,7 @@ class ormStyle
 	 */
 	public function HasAltStyleClass(): bool
 	{
-		return utils::StrLen($this->sAltStyleClass) > 0;
+		return utils::IsNotNullOrEmptyString($this->sAltStyleClass);
 	}
 
 	/**
@@ -162,7 +162,7 @@ class ormStyle
 	 */
 	public function SetAltStyleClass(?string $sAltStyleClass)
 	{
-		$this->sAltStyleClass = (utils::StrLen($sAltStyleClass) === 0) ? null : $sAltStyleClass;
+		$this->sAltStyleClass = utils::IsNullOrEmptyString($sAltStyleClass) ? null : $sAltStyleClass;
 		return $this;
 	}
 
@@ -172,7 +172,7 @@ class ormStyle
 	 */
 	public function HasDecorationClasses(): bool
 	{
-		return utils::StrLen($this->sDecorationClasses) > 0;
+		return utils::IsNotNullOrEmptyString($this->sDecorationClasses);
 	}
 
 	/**
@@ -190,7 +190,7 @@ class ormStyle
 	 */
 	public function SetDecorationClasses(?string $sDecorationClasses)
 	{
-		$this->sDecorationClasses = (utils::StrLen($sDecorationClasses) === 0) ? null : $sDecorationClasses;
+		$this->sDecorationClasses = utils::IsNullOrEmptyString($sDecorationClasses) ? null : $sDecorationClasses;
 		return $this;
 	}
 
@@ -200,7 +200,7 @@ class ormStyle
 	 */
 	public function HasIcon(): bool
 	{
-		return utils::StrLen($this->sIcon) > 0;
+		return utils::IsNotNullOrEmptyString($this->sIcon);
 	}
 
 	/**
@@ -210,7 +210,7 @@ class ormStyle
 	 */
 	public function SetIcon(?string $sIcon)
 	{
-		$this->sIcon = (utils::StrLen($sIcon) === 0) ? null : $sIcon;
+		$this->sIcon = utils::IsNullOrEmptyString($sIcon) ? null : $sIcon;
 		return $this;
 	}
 
diff --git a/sources/application/UI/Base/Component/Button/ButtonUIBlockFactory.php b/sources/application/UI/Base/Component/Button/ButtonUIBlockFactory.php
index fa03c643d..0b9d5b875 100644
--- a/sources/application/UI/Base/Component/Button/ButtonUIBlockFactory.php
+++ b/sources/application/UI/Base/Component/Button/ButtonUIBlockFactory.php
@@ -424,11 +424,11 @@ class ButtonUIBlockFactory extends AbstractUIBlockFactory
 		$oButton->SetActionType($sActionType)
 			->SetColor($sColor);
 
-		if (utils::StrLen($sValue) > 0) {
+		if (utils::IsNotNullOrEmptyString($sValue)) {
 			$oButton->SetValue($sValue);
 		}
 
-		if (utils::StrLen($sName) > 0) {
+		if (utils::IsNotNullOrEmptyString($sName)) {
 			$oButton->SetName($sName);
 		}
 
diff --git a/sources/application/UI/Base/Component/Input/InputWithLabel.php b/sources/application/UI/Base/Component/Input/InputWithLabel.php
index b7ce8f4d9..09931a4f6 100644
--- a/sources/application/UI/Base/Component/Input/InputWithLabel.php
+++ b/sources/application/UI/Base/Component/Input/InputWithLabel.php
@@ -135,7 +135,7 @@ class InputWithLabel extends UIBlock
 	 */
 	public function HasDescription(): bool
 	{
-		return utils::StrLen($this->sDescription) > 0;
+		return utils::IsNotNullOrEmptyString($this->sDescription);
 	}
 
 }
\ No newline at end of file