Function _add_vdom_to_etree

src/py/reactpy/reactpy/utils.py:159–199

(parent: etree._Element, vdom: VdomDict | dict[str, Any])

def _add_vdom_to_etree(parent: etree._Element, vdom: VdomDict | dict[str, Any]) -> None:
    try:
        tag = vdom["tagName"]
    except KeyError as e:
        msg = f"Expected a VDOM dict, not {vdom}"
        raise TypeError(msg) from e
    else:
        vdom = cast(VdomDict, vdom)

    if tag:
        element = etree.SubElement(parent, tag)
        element.attrib.update(
            _vdom_attr_to_html_str(k, v) for k, v in vdom.get("attributes", {}).items()
        )
    else:
        element = parent

    for c in vdom.get("children", []):
        if isinstance(c, dict):
            _add_vdom_to_etree(element, c)
        else:
            """
            LXML handles string children by storing them under `text` and `tail`
            attributes of Element objects. The `text` attribute, if present, effectively
            becomes that element's first child. Then the `tail` attribute, if present,
            becomes a sibling that follows that element. For example, consider the
            following HTML:

                <p><a>hello</a>world</p>

            In this code sample, "hello" is the `text` attribute of the `<a>` element
            and "world" is the `tail` attribute of that same `<a>` element. It&#x27;s for
            this reason that, depending on whether the element being constructed has
            non-string a child element, we need to assign a `text` vs `tail` attribute
            to that element or the last non-string child respectively.
            """
            if len(element):
                last_child = element[-1]
                last_child.tail = f"{last_child.tail or ''}{c}"
            else:
                element.text = f"{element.text or ''}{c}"


def _mutate_vdom(vdom: VdomDict) -> None: