@@ -64,3 +64,82 @@ var b strings.Builder
 	_ = c.Render(&b)
 	return b.String()
 }
+
+// JoinAttrs with the given name only on the first level of the given nodes.
+// This means that attributes on non-direct descendants are ignored.
+// Attribute values are joined by spaces.
+// Note that this renders all first-level attributes to check whether they should be processed.
+func JoinAttrs(name string, children ...g.Node) g.Node {
+	var attrValues []string
+	var result []g.Node
+	firstAttrIndex := -1
+
+	// Process all children
+	for _, child := range children {
+		// Handle groups explicitly because they may contain attributes
+		if group, ok := child.(g.Group); ok {
+			for _, groupChild := range group {
+				isGivenAttr, attrValue := extractAttrValue(name, groupChild)
+				if !isGivenAttr || attrValue == "" {
+					result = append(result, groupChild)
+					continue
+				}
+
+				attrValues = append(attrValues, attrValue)
+				if firstAttrIndex == -1 {
+					firstAttrIndex = len(result)
+					result = append(result, nil)
+				}
+			}
+
+			continue
+		}
+
+		// Handle non-group nodes essentially the same way
+		isGivenAttr, attrValue := extractAttrValue(name, child)
+		if !isGivenAttr || attrValue == "" {
+			result = append(result, child)
+			continue
+		}
+
+		attrValues = append(attrValues, attrValue)
+		if firstAttrIndex == -1 {
+			firstAttrIndex = len(result)
+			result = append(result, nil)
+		}
+	}
+
+	// If no attributes were found, just return the result now
+	if firstAttrIndex == -1 {
+		return g.Group(result)
+	}
+
+	// Insert joined attribute at the position of the first attribute
+	result[firstAttrIndex] = g.Attr(name, strings.Join(attrValues, " "))
+	return g.Group(result)
+}
+
+type nodeTypeDescriber interface {
+	Type() g.NodeType
+}
+
+func extractAttrValue(name string, n g.Node) (bool, string) {
+	// Ignore everything that is not an attribute
+	if n, ok := n.(nodeTypeDescriber); !ok || n.Type() == g.ElementType {
+		return false, ""
+	}
+
+	var b strings.Builder
+	if err := n.Render(&b); err != nil {
+		return false, ""
+	}
+
+	rendered := b.String()
+	if !strings.HasPrefix(rendered, " "+name+`="`) || !strings.HasSuffix(rendered, `"`) {
+		return false, ""
+	}
+
+	v := strings.TrimPrefix(rendered, " "+name+`="`)
+	v = strings.TrimSuffix(v, `"`)
+	return true, v
+}