Move yaml loading functions from DataLoader into a utility module.

lib/ansible/parsing/utils/yaml.py

@@ -0,0 +1,91 @@
+# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
+# Copyright: (c) 2017, Ansible Project
+# Copyright: (c) 2018, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import json
+
+from yaml import YAMLError
+
+from ansible.errors import AnsibleParserError
+from ansible.errors.yaml_strings import YAML_SYNTAX_ERROR
+from ansible.module_utils.six import text_type
+from ansible.module_utils._text import to_native
+from ansible.parsing.yaml.loader import AnsibleLoader
+from ansible.parsing.yaml.objects import AnsibleBaseYAMLObject, AnsibleUnicode
+
+
+__all__ = ('from_yaml',)
+
+
+def _handle_error(yaml_exc, file_name, show_content):
+    '''
+    Optionally constructs an object (AnsibleBaseYAMLObject) to encapsulate the
+    file name/position where a YAML exception occurred, and raises an AnsibleParserError
+    to display the syntax exception information.
+    '''
+
+    # if the YAML exception contains a problem mark, use it to construct
+    # an object the error class can use to display the faulty line
+    err_obj = None
+    if hasattr(yaml_exc, 'problem_mark'):
+        err_obj = AnsibleBaseYAMLObject()
+        err_obj.ansible_pos = (file_name, yaml_exc.problem_mark.line + 1, yaml_exc.problem_mark.column + 1)
+
+    err_msg = getattr(yaml_exc, 'problem', '')
+
+    raise AnsibleParserError(YAML_SYNTAX_ERROR % to_native(err_msg), obj=err_obj, show_content=show_content, orig_exc=yaml_exc)
+
+
+def _safe_load(stream, file_name=None, vault_secrets=None):
+    ''' Implements yaml.safe_load(), except using our custom loader class. '''
+
+    loader = AnsibleLoader(stream, file_name, vault_secrets)
+    try:
+        return loader.get_single_data()
+    finally:
+        try:
+            loader.dispose()
+        except AttributeError:
+            pass  # older versions of yaml don't have dispose function, ignore
+
+
+def from_yaml(data, file_name='<string>', show_content=True):
+    '''
+    Creates a python datastructure from the given data, which can be either
+    a JSON or YAML string.
+    '''
+    new_data = None
+
+    if isinstance(data, AnsibleUnicode):
+        # The PyYAML's libyaml bindings use PyUnicode_CheckExact so
+        # they are unable to cope with our subclass.
+        # Unwrap and re-wrap the unicode so we can keep track of line
+        # numbers
+        # Note: Cannot use to_text() because AnsibleUnicode is a subclass of the text_type.
+        # Should not have to worry about tracebacks because python's text constructors (unicode() on
+        # python2 and str() on python3) can handle a subtype of themselves.
+        in_data = text_type(data)
+    else:
+        in_data = data
+
+    try:
+        # we first try to load this data as JSON.  Fixes issues with extra vars json strings not
+        # being parsed correctly by the yaml parser
+        new_data = json.loads(in_data)
+    except Exception:
+        # must not be JSON, let the rest try
+        try:
+            new_data = _safe_load(in_data, file_name=file_name)
+        except YAMLError as yaml_exc:
+            _handle_error(yaml_exc, file_name, show_content)
+
+        if isinstance(data, AnsibleUnicode):
+            new_data = AnsibleUnicode(new_data)
+            new_data.ansible_pos = data.ansible_pos
+
+    return new_data