Source code for parsel.xpathfuncs

import re
from typing import Any, Callable, Optional

from lxml import etree

from w3lib.html import HTML5_WHITESPACE

regex = f"[{HTML5_WHITESPACE}]+"
replace_html5_whitespaces = re.compile(regex).sub

[docs]def set_xpathfunc(fname: str, func: Optional[Callable]) -> None: # type: ignore[type-arg] """Register a custom extension function to use in XPath expressions. The function ``func`` registered under ``fname`` identifier will be called for every matching node, being passed a ``context`` parameter as well as any parameters passed from the corresponding XPath expression. If ``func`` is ``None``, the extension function will be removed. See more `in lxml documentation`_. .. _`in lxml documentation`: """ ns_fns = etree.FunctionNamespace(None) # type: ignore[attr-defined] if func is not None: ns_fns[fname] = func else: del ns_fns[fname]
def setup() -> None: set_xpathfunc("has-class", has_class) def has_class(context: Any, *classes: str) -> bool: """has-class function. Return True if all ``classes`` are present in element's class attr. """ if not context.eval_context.get("args_checked"): if not classes: raise ValueError( "XPath error: has-class must have at least 1 argument" ) for c in classes: if not isinstance(c, str): raise ValueError( "XPath error: has-class arguments must be strings" ) context.eval_context["args_checked"] = True node_cls = context.context_node.get("class") if node_cls is None: return False node_cls = " " + node_cls + " " node_cls = replace_html5_whitespaces(" ", node_cls) for cls in classes: if " " + cls + " " not in node_cls: return False return True