Fix bug with child node order when there are pattern nodes

Author: frmdstryr

CHANGELOG.md

@@ -1,3 +1,8 @@
+# 0.11.3
+
+- Include new index in added and moved modification events
+- Fix bug where pattern nodes caused nodes to be inserted in the incorrect order
+
 # 0.11.2
 
 - Fix error when `Raw` node source is empty string.

setup.py

@@ -15,7 +15,7 @@
 
 setup(
     name='enaml-web',
-    version='0.11.2',
+    version='0.11.3',
     author='CodeLV',
     author_email='[email protected]',
     url='https://github.com/codelv/enaml-web',

tests/test_html.py

@@ -678,6 +678,12 @@ def on_modified(change):
     r = [li.text for li in view.proxy.widget.xpath("/html/body/ul/li")]
     assert r == ["1", "2", "4", "5"]
 
+    # Trigger condition
     view.render(menu=["3", "4"])
     r = [li.text for li in view.proxy.widget.xpath("/html/body/ul/li")]
     assert r == ["1", "2", "3", "4", "5"]
+
+    # Remove condition
+    view.render(menu=["4", "3"])
+    r = [li.text for li in view.proxy.widget.xpath("/html/body/ul/li")]
+    assert r == ["1", "4", "3", "5"]

web/components/html.py

@@ -212,6 +212,7 @@ def child_added(self, child: Declarative):
                         "type": "added",
                         "name": "children",
                         "value": child.render(),
+                        "index": self._child_index(child),
                         "before": self._next_child_id(child),
                     },
                 )
@@ -231,6 +232,7 @@ def child_moved(self, child: Declarative):
                         "type": "moved",
                         "name": "children",
                         "value": child.id,
+                        "index": self._child_index(child),
                         "before": self._next_child_id(child),
                     },
                 )
@@ -266,6 +268,16 @@ def _notify_modified(self, root: Optional[Tag], change: ChangeDict):
         if root is not None:
             root.modified(change)
 
+    def _child_index(self, child: Tag) -> int:
+        """Find the index of the child ignoring any pattern nodes"""
+        i = 0
+        for c in self.children:
+            if c is child:
+                return i
+            elif isinstance(c, Tag):
+                i += 1
+        raise ValueError("Child not found")
+
     def _next_child_id(self, child: Tag) -> Optional[str]:
         """Find the id of the node after this child."""
         # Indicate where it was added

web/impl/lxml_toolkit_object.py

@@ -154,41 +154,34 @@ def destroy(self):
     def child_added(self, child: WebComponent):
         """Handle the child added event from the declaration.
 
-        This handler will insert the child toolkit widget in the correct.
-        position. Subclasses which need more control should reimplement this
-        method.
+        This handler will insert the child into the tree at the
+        appropriate index.
 
         """
+        w = self.widget
+        if w is None:
+            return
+
         # Use insert to put in the correct spot
         d = self.declaration
         assert d is not None
-        i = d.children.index(child.declaration)
-        widget = self.widget
-        if widget is None:
-            return False
-        widget.insert(i, child.widget)
+        i = d._child_index(child.declaration)
+        w.insert(i, child.widget)
 
-    def child_moved(self, child: WebComponent):
+    def child_moved(self, child: WebComponent) -> bool:
         """Handle the child moved event from the declaration.
 
         This handler will pop the child and insert it in the correct position
         if it isn't already there.
 
-        Subclasses which need more control should reimplement this method.
-
-        Returns
-        -------
-        was_moved: Bool
-            Whether a move was performed or not
-
         """
-        # Determine the new index
-        d = self.declaration
-        assert d is not None
-        i = d.children.index(child.declaration)
         w = self.widget
         if w is None:
             return False
+        # Determine the new index
+        d = self.declaration
+        assert d is not None
+        i = d._child_index(child.declaration)
         j = w.index(child.widget)
         if j == i:
             return False  # Already in the correct spot