Add render_orphans() to render elements without parents.

Fixes #22.

docs/usage.md

@@ -290,6 +290,19 @@ snippets as attributes:
 <ul data-li-template="&lt;li class=&#34;bar&#34;&gt;&lt;/li&gt;"></ul>
 ```
 
+## Render elements without a parent (orphans)
+
+In some cases such as returning partial content it is useful to render elements
+without a parent element. This is useful in HTMX partial responses.
+
+You may use `render_orphans` to achieve this:
+
+```pycon title="Render orphan elements without a parent"
+>>> from htpy import render_orphans, tr
+>>> print(render_orphans([tr["a"], tr["b"]]))
+<tr>a</tr><tr>b</tr>
+```
+
 ## Iterating of the Output
 
 Iterating over a htpy element will yield the resulting contents in chunks as

htpy/__init__.py

@@ -217,6 +217,10 @@ def __iter__(self) -> Iterator[str]:
         yield f"<{self._name}{_attrs_string(self._attrs)}>"
 
 
+def render_orphans(orhpans: Iterable[BaseElement]) -> _Markup:
+    return "".join(_iter_children(orhpans))
+
+
 class _HasHtml(Protocol):
     def __html__(self) -> str: ...
 

tests/test_render_orphans.py

@@ -0,0 +1,7 @@
+from htpy import render_orphans, tr
+
+
+def test_render_orphan() -> None:
+    result = render_orphans([tr["a"], tr["b"]])
+
+    assert result == "<tr>a</tr><tr>b</tr>"