Function _vdom_attr_to_html_str

src/py/reactpy/reactpy/utils.py:266–299

(key: str, value: Any)

def _vdom_attr_to_html_str(key: str, value: Any) -> tuple[str, str]:
    if key == "style":
        if isinstance(value, dict):
            value = ";".join(
                # We lower only to normalize - CSS is case-insensitive:
                # https://www.w3.org/TR/css-fonts-3/#font-family-casing
                f"{_CAMEL_CASE_SUB_PATTERN.sub('-', k).lower()}:{v}"
                for k, v in value.items()
            )
    elif (
        # camel to data-* attributes
        key.startswith("data_")
        # camel to aria-* attributes
        or key.startswith("aria_")
        # handle special cases
        or key in DASHED_HTML_ATTRS
    ):
        key = key.replace("_", "-")
    elif (
        # camel to data-* attributes
        key.startswith("data")
        # camel to aria-* attributes
        or key.startswith("aria")
        # handle special cases
        or key in DASHED_HTML_ATTRS
    ):
        key = _CAMEL_CASE_SUB_PATTERN.sub("-", key)

    if callable(value):  # nocov
        raise TypeError(f"Cannot convert callable attribute {key}={value} to HTML")

    # Again, we lower the attribute name only to normalize - HTML is case-insensitive:
    # http://w3c.github.io/html-reference/documents.html#case-insensitivity
    return key.lower(), str(value)


# see list of HTML attributes with dashes in them: