Removed `yaml` option from meta-data extension.

The option was buggy. Rather than try to fix it, it is being removed.
This feeture should exist as a seperate extension. Fixes #390.

4 files changed, 16 insertions, 74 deletions

diff --git a/docs/extensions/meta_data.txt b/docs/extensions/meta_data.txt
index 3057bfa..4a4fe62 100644
--- a/docs/extensions/meta_data.txt
+++ b/docs/extensions/meta_data.txt
@@ -47,10 +47,11 @@ many lines as desired.
 The first blank line ends all meta-data for the document. Therefore, the first
 line of a document must not be blank.
 
-Alternatively, if the first line in the document is `---`, a YAML document
-separator, then the meta-data is searched for between it and the next `---`
-(or `...`) line. Even though YAML deliminators are supported, meta-data is
-not parsed as YAML unless the `yaml` option is set (see below).
+Alternatively, You may use YAML style deliminators to mark the start and/or end
+of your meta-data. When doing so, the first line of your document must be `---`.
+The meta-data ends at the first blank line or the first line containing an end
+deliminator (either `---` or `...`), whichever comes first. Even though YAML
+deliminators are supported, meta-data is not parsed as YAML.
 
 All meta-data is stripped from the document prior to any further processing
 by Markdown.
@@ -61,16 +62,6 @@ Usage
 See [Extensions](index.html) for general extension usage, specify `markdown.extensions.meta`
 as the name of the extension.
 
-The following options are provided to configure the output:
-
-* **`yaml`**: Support meta-data specified in YAML format.
-
-    Default: `False`
-
-    If `yaml` is set to `True`, the lines between `---` separators are parsed
-    as a full YAML object. PyYAML is required for this, and a warning is
-    issued if PyYAML (or equivalent) is not available.
-
 Accessing the Meta-Data
 -----------------------
 
@@ -100,11 +91,6 @@ line breaks if desired. Or the items could be joined where appropriate. No
 assumptions are made regarding the data. It is simply passed as found to the 
 `Meta` attribute.
 
-Note, if `yaml` option is set, the resulting `Meta` attribute is the object as
-returned by `yaml.load()` and may deviate significantly from the above
-description (e.g. may be a list of dictionaries, with value objects other than
-strings, ...).
-
 Perhaps the meta-data could be passed into a template system, or used by
 various Markdown extensions. The possibilities are left to the imagination of
 the developer.
diff --git a/docs/release-2.6.txt b/docs/release-2.6.txt
index f79e357..747c81c 100644
--- a/docs/release-2.6.txt
+++ b/docs/release-2.6.txt
@@ -198,11 +198,15 @@ meta-data. By default, the YAML deliminators are recognized, however, the
 actual data is parsed as previously.  This follows the syntax of
 [MultiMarkdown], which inspired this extension.
 
-Alternatively, if the `yaml` option is set, then the data is parsed as YAML.
+<del>Alternatively, if the `yaml` option is set, then the data is parsed as YAML.</del>
+<ins>As the `yaml` option was buggy, it was removed in 2.6.1. It is suggested that a third
+party extension be used if you want true YAML support. See [Issue #390][#390] for a full
+explanation.</ins>
 
 [MultiMarkdown]: http://fletcherpenney.net/MultiMarkdown_Syntax_Guide#metadata
 [Meta-Data]: extensions/meta_data.html
 [YAML]: http://yaml.org/
+[#390]: https://github.com/waylan/Python-Markdown/issues/390
 
 ### Table of Contents Extension Refactored
 
diff --git a/markdown/extensions/meta.py b/markdown/extensions/meta.py
index cf8074f..711235e 100644
--- a/markdown/extensions/meta.py
+++ b/markdown/extensions/meta.py
@@ -22,66 +22,40 @@ from ..preprocessors import Preprocessor
 import re
 import logging
 
-try:  # pragma: no cover
-    import yaml
-    try:
-        from yaml import CSafeLoader as SafeLoader
-    except ImportError:
-        from yaml import SafeLoader
-except ImportError:
-    yaml = None
-
 log = logging.getLogger('MARKDOWN')
 
 # Global Vars
 META_RE = re.compile(r'^[ ]{0,3}(?P<key>[A-Za-z0-9_-]+):\s*(?P<value>.*)')
 META_MORE_RE = re.compile(r'^[ ]{4,}(?P<value>.*)')
-YAML_BEGIN_RE = re.compile(r'^-{3}(\s.*)?')
-YAML_END_RE = re.compile(r'^(-{3}|\.{3})(\s.*)?')
+BEGIN_RE = re.compile(r'^-{3}(\s.*)?')
+END_RE = re.compile(r'^(-{3}|\.{3})(\s.*)?')
 
 
 class MetaExtension (Extension):
     """ Meta-Data extension for Python-Markdown. """
-    def __init__(self, *args, **kwargs):
-        self.config = {
-            'yaml': [False, "Parse meta data specified as a "
-                            "'---' delimited YAML front matter"],
-            }
-        super(MetaExtension, self).__init__(*args, **kwargs)
 
     def extendMarkdown(self, md, md_globals):
         """ Add MetaPreprocessor to Markdown instance. """
         md.preprocessors.add("meta",
-                             MetaPreprocessor(md, self.getConfigs()),
+                             MetaPreprocessor(md),
                              ">normalize_whitespace")
 
 
 class MetaPreprocessor(Preprocessor):
     """ Get Meta-Data. """
 
-    def __init__(self, md, config):
-        self.config = config
-        super(MetaPreprocessor, self).__init__(md)
-
     def run(self, lines):
         """ Parse Meta-Data and store in Markdown.Meta. """
         meta = {}
         key = None
-        yaml_block = []
-        have_yaml = False
-        if lines and YAML_BEGIN_RE.match(lines[0]):
-            have_yaml = True
+        if lines and BEGIN_RE.match(lines[0]):
             lines.pop(0)
-            if self.config['yaml'] and not yaml:  # pragma: no cover
-                log.warning('Document with YAML header, but PyYAML unavailable')
         while lines:
             line = lines.pop(0)
             m1 = META_RE.match(line)
-            if line.strip() == '' or have_yaml and YAML_END_RE.match(line):
+            if line.strip() == '' or END_RE.match(line):
                 break  # blank line or end of YAML header - done
-            elif have_yaml and self.config['yaml'] and yaml:
-                yaml_block.append(line)
-            elif m1:
+            if m1:
                 key = m1.group('key').lower().strip()
                 value = m1.group('value').strip()
                 try:
@@ -96,8 +70,6 @@ class MetaPreprocessor(Preprocessor):
                 else:
                     lines.insert(0, line)
                     break  # no meta data - done
-        if yaml_block:
-            meta = yaml.load('\n'.join(yaml_block), SafeLoader)
         self.markdown.Meta = meta
         return lines
 
diff --git a/tests/test_extensions.py b/tests/test_extensions.py
index 6a57878..38f0be3 100644
--- a/tests/test_extensions.py
+++ b/tests/test_extensions.py
@@ -8,7 +8,6 @@ continue to work as advertised. This used to be accomplished by doctests.
 """
 
 from __future__ import unicode_literals
-import datetime
 import unittest
 import markdown
 
@@ -510,25 +509,6 @@ The body. This is paragraph one.'''
         self.assertEqual(self.md.convert(text), '')
         self.assertEqual(self.md.Meta, {'title': ['No newline']})
 
-    def testYamlObjectMetaData(self):
-        """ Test metadata specified as a complex YAML object. """
-        md = markdown.Markdown(extensions=[markdown.extensions.meta.MetaExtension(yaml=True)])
-        text = '''---
-Author: John Doe
-Date: 2014-11-29 14:15:16
-Integer: 0x16
----
-
-Some content.'''
-        self.assertEqual(md.convert(text), '<p>Some content.</p>')
-        self.assertEqual(
-            md.Meta, {
-                'Author': 'John Doe',
-                'Date': datetime.datetime(2014, 11, 29, 14, 15, 16),
-                'Integer': 22
-            }
-        )
-
 
 class TestWikiLinks(unittest.TestCase):
     """ Test Wikilinks Extension. """