--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.7/site-packages/planemo/xml/validation.py	Sat May 02 07:14:21 2020 -0400
@@ -0,0 +1,92 @@
+"""Module describing abstractions for validating XML content."""
+import abc
+import subprocess
+from collections import namedtuple
+
+from galaxy.tool_util.deps.commands import which
+from galaxy.util import unicodify
+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'.")
+
+
+class XsdValidator(object):
+    """Class allowing validation of XML files against XSD schema."""
+
+    __metaclass__ = abc.ABCMeta
+
+    @abc.abstractmethod
+    def validate(self, schema_path, target_path):
+        """Validate ``target_path`` against ``schema_path``.
+
+        :return type: ValidationResult
+        """
+
+    @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()]
+
+
+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",
+)