3 files changed, 32 insertions, 0 deletions
diff --git a/htmtl/htmtl.py b/htmtl/htmtl.py
index 885fe94..7732f06 100644
--- a/htmtl/htmtl.py
+++ b/htmtl/htmtl.py
@@ -11,6 +11,8 @@ from .parsers.outer_text import OuterText
 from .modifier import Modifier
 from .modifiers.truncate import Truncate
 from .expression_parser import ExpressionParser
+from .parsers.when import When
+from .parsers.when_not import WhenNot
 
 
 class Htmtl:
@@ -32,6 +34,8 @@ class Htmtl:
             OuterHtml,
             OuterPartial,
             GenericValue,
+            When,
+            WhenNot,
         ]
 
         # set default expression modifiers
diff --git a/htmtl/parsers/when.py b/htmtl/parsers/when.py
new file mode 100644
index 0000000..57a965a
--- /dev/null
+++ b/htmtl/parsers/when.py
@@ -0,0 +1,14 @@
+from typing import Optional
+from dompa.nodes import Node
+from ..parser import Parser
+
+
+class When(Parser):
+    def traverse(self, node: Node) -> Optional[Node]:
+        if "when" in node.attributes:
+            if not self.expression(node.attributes["when"]):
+                return None
+
+            node.attributes.pop("when")
+
+        return node
+\ No newline at end of file
diff --git a/htmtl/parsers/when_not.py b/htmtl/parsers/when_not.py
new file mode 100644
index 0000000..68e3d09
--- /dev/null
+++ b/htmtl/parsers/when_not.py
@@ -0,0 +1,14 @@
+from typing import Optional
+from dompa.nodes import Node
+from ..parser import Parser
+
+
+class WhenNot(Parser):
+    def traverse(self, node: Node) -> Optional[Node]:
+        if "when-not" in node.attributes:
+            if self.expression(node.attributes["when-not"]):
+                return None
+
+            node.attributes.pop("when-not")
+
+        return node
+\ No newline at end of file