Keep the same type as result of If, to avoid types matchers to fail

class.go

@@ -4,19 +4,11 @@ package gomplements
 type Class string
 
 // If allows to add a CSS class to an Element, only if a condition is met.
-func (c Class) If(condition bool) ParentModifier {
-	return &conditionalClass{class: c, cond: condition}
-}
-
-type conditionalClass struct {
-	class Class
-	cond  bool
-}
-
-func (c *conditionalClass) ModifyParent(p Element) {
-	if c.cond {
-		p.With(c.class)
+func (c Class) If(condition bool) Class {
+	if condition {
+		return c
 	}
+	return ""
 }
 
 // Classes contains multiple CSS classes to be applied in the class attribute of an Element.
@@ -28,8 +20,11 @@ func (c Classes) Classes() []Class {
 }
 
 // If allows to add multiple CSS classes to an Element, only if a condition is met.
-func (c Classes) If(condition bool) ParentModifier {
-	return &conditionalClasses{classes: c, cond: condition}
+func (c Classes) If(cond bool) Classes {
+	if cond {
+		return c
+	}
+	return []Class{}
 }
 
 type conditionalClasses struct {

elem.go

@@ -74,38 +74,67 @@ func (e *elem) With(children ...any) Element {
 	for _, c := range children {
 		switch c := c.(type) {
 		case func(...gomponents.Node) gomponents.Node:
+			if c == nil {
+				continue
+			}
 			e.elemFn = c
 		case Class:
-			e.classes[c] = true
+			if c != "" {
+				e.classes[c] = true
+			}
 		case Classer:
-			e.classes[c.Class()] = true
+			cl := c.Class()
+			if cl != "" {
+				e.classes[cl] = true
+			}
 		case Classeser:
 			for _, cl := range c.Classes() {
-				e.classes[cl] = true
+				if cl != "" {
+					e.classes[cl] = true
+				}
 			}
 		case Styles:
 			for prop, val := range c {
 				e.styles[prop] = val
 			}
 		case ParentModifierAndNode:
+			if c == nil {
+				continue
+			}
 			c.ModifyParent(e)
 			e.elements = append(e.elements, c)
 		case ParentModifier:
+			if c == nil {
+				continue
+			}
 			c.ModifyParent(e)
 		case Element:
+			if c == nil {
+				continue
+			}
 			e.elements = append(e.elements, c)
 		case gomponents.Node:
+			if c == nil {
+				continue
+			}
 			if IsAttribute(c) {
 				e.attributes = append(e.attributes, c)
 			} else {
 				e.elements = append(e.elements, c)
 			}
 		case ID:
-			e.attributes = append(e.attributes, html.ID(string(c)))
+			if c != "" {
+				e.attributes = append(e.attributes, html.ID(string(c)))
+			}
 		case string:
-			e.elements = append(e.elements, gomponents.Text(c))
+			if c != "" {
+				e.elements = append(e.elements, gomponents.Text(c))
+			}
 		case fmt.Stringer:
-			e.elements = append(e.elements, gomponents.Text(c.String()))
+			s := c.String()
+			if s != "" {
+				e.elements = append(e.elements, gomponents.Text(s))
+			}
 		case []any:
 			e.With(c...)
 		}

styles.go

@@ -4,17 +4,9 @@ package gomplements
 type Styles map[string]string
 
 // If allows to apply CSS styles to an Element, only if a condition is met.
-func (s Styles) If(cond bool) ParentModifier {
-	return &conditionalStyles{styles: s, cond: cond}
-}
-
-type conditionalStyles struct {
-	styles Styles
-	cond   bool
-}
-
-func (c *conditionalStyles) ModifyParent(p Element) {
-	if c.cond {
-		p.With(c.styles)
+func (s Styles) If(cond bool) Styles {
+	if cond {
+		return s
 	}
+	return Styles{}
 }