Source code for planemo.xml.validation

"""Module describing abstractions for validating XML content."""
import abc
import subprocess
from collections import namedtuple

from galaxy.util import unicodify
from galaxy.util.commands import which

try:
    from lxml import etree
except ImportError:
    etree = None

XMLLINT_COMMAND = "xmllint --noout --schema {0} {1} 2>&1"
INSTALL_VALIDATOR_MESSAGE = (
    "This feature requires an external dependency "
    "to function, pleaes install xmllint (e.g 'brew "
    "install libxml2' or 'apt-get install "
    "libxml2-utils'."
)


[docs]class XsdValidator(metaclass=abc.ABCMeta): """Class allowing validation of XML files against XSD schema."""
[docs] @abc.abstractmethod def validate(self, schema_path, target_path): """Validate ``target_path`` against ``schema_path``. :return type: ValidationResult """
[docs] @abc.abstractmethod def enabled(self): """Return True iff system has dependencies for this validator. :return type: bool """
ValidationResult = namedtuple("ValidationResult", ["passed", "output"]) class LxmlValidator(XsdValidator): """Validate XSD files using lxml library.""" def validate(self, schema_path, target_path): try: xsd_doc = etree.parse(schema_path) xsd = etree.XMLSchema(xsd_doc) xml = etree.parse(target_path) passed = xsd.validate(xml) return ValidationResult(passed, xsd.error_log) except etree.XMLSyntaxError as e: return ValidationResult(False, unicodify(e)) def enabled(self): return etree is not None class XmllintValidator(XsdValidator): """Validate XSD files with the external tool xmllint.""" def validate(self, schema_path, target_path): command = XMLLINT_COMMAND.format(schema_path, target_path) p = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True) stdout, _ = p.communicate() passed = p.returncode == 0 return ValidationResult(passed, stdout) def enabled(self): return bool(which("xmllint")) VALIDATORS = [LxmlValidator(), XmllintValidator()]
[docs]def get_validator(require=True): """Return a :class:`XsdValidator` object based on available dependencies.""" for validator in VALIDATORS: if validator.enabled(): return validator if require: raise Exception(INSTALL_VALIDATOR_MESSAGE) return None
__all__ = ( "get_validator", "XsdValidator", )