Changeset 5848

Timestamp:

12 Mar 2011, 13:57:24 (14 years ago)

Author:

uli

Message:

Add helper functions to turn ReStructuredText? into HTML.

This can be nice to implement some poor-mans-editor. We can for
example define textareas in forms and render the input as
ReStructuredText? in other pages.

File:

• main/waeup.sirp/trunk/src/waeup/sirp/utils/helpers.py (modified) (2 diffs)

main/waeup.sirp/trunk/src/waeup/sirp/utils/helpers.py

@@ -6 +6 @@
 import shutil
 import grok
+from cStringIO import StringIO
+from docutils.core import publish_string
 from zope.component.interfaces import IFactory
 from zope.interface import implementedBy
@@ -233 +235 @@
         # Required by IFactory
         return implementedBy(self.factory)
+
+def ReST2HTML_w_warnings(source_string):
+    """Convert a reStructuredText string to HTML preserving warnings.
+
+    Returns a tuple ``(<HTML_CODE>, <WARNINGS>)``, both being
+    strings. Where ``<HTML_CODE>`` is the HTML code generated from the
+    source string, ``<WARNINGS>`` is a string containing any warning
+    messages or ``None``.
+    
+    Regular multi-line ReStructuredText strings will be returned as
+    HTML code:
+
+        >>> from waeup.sirp.utils.helpers import ReST2HTML
+        >>> source = '''
+        ... Headline
+        ... ========
+        ...
+        ... - A list item
+        ... - Another item
+        ...
+        ... Thanks for watching!
+        ... '''
+        >>> html, warnings = ReST2HTML_w_warnings(source)
+        >>> print html
+        <div class="document" id="headline">
+        <h1 class="title">Headline</h1>
+        <BLANKLINE>
+        <ul class="simple">
+        <li>A list item</li>
+        <li>Another item</li>
+        </ul>
+        <p>Thanks for watching!</p>
+        </div>
+
+    Here no warnings happened, so the `warnings` are ``None``:
+
+        >>> warnings is None
+        True
+        
+    If warnings happen then they can be retrieved in the returned
+    ``warnings``. We try to render an erraneous document:
+
+        >>> source = '''
+        ... Headline
+        ... ======
+        ...
+        ... Thanks for watching!
+        ... '''
+        >>> html, warnings = ReST2HTML_w_warnings(source)
+        >>> print html
+        <div class="document" id="headline">
+        <h1 class="title">Headline</h1>
+        <BLANKLINE>
+        <p>Thanks for watching!</p>
+        </div>
+
+        >>> print warnings
+        <string>:3: (WARNING/2) Title underline too short.
+        <BLANKLINE>
+        Headline
+        ======
+        <BLANKLINE>
+
+    As you can see, the warnings are not displayed inline the document
+    but can be retrieved from the returned warnings, which is a string
+    or ``None``.
+    """
+    warnings = StringIO()
+    fulldoc = publish_string(
+        source_string, writer_name='html4css1',
+        settings_overrides={
+            'report_level': 0,
+            'warning_stream': warnings,
+            })
+    warnings.seek(0)
+    warning_msgs = warnings.read()
+    if warning_msgs:
+        # Render again, this time with no warnings inline...
+        fulldoc =  publish_string(
+        source_string, writer_name='html4css1',
+        settings_overrides={
+            'report_level': 10000,
+            'halt_level': 10000,
+            'warning_stream': warnings,
+            })
+    if warning_msgs == '':
+        warning_msgs = None
+    return getInnerHTMLPart(fulldoc).strip(), warning_msgs
+
+def ReST2HTML(source_string):
+    """Render a string containing ReStructuredText to HTML.
+
+    Any warnings about too short headings, etc. are silently
+    discarded. Use :func:`ReST2HTML_w_warnings` if you want to get any
+    warnings.
+
+    A regular document will be rendered like this:
+
+        >>> source = '''
+        ... Headline
+        ... ========
+        ...
+        ... Thanks for watching!
+        ... '''
+        >>> html = ReST2HTML(source)
+        >>> print html
+        <div class="document" id="headline">
+        <h1 class="title">Headline</h1>
+        <BLANKLINE>
+        <p>Thanks for watching!</p>
+        </div>
+
+    A document with markup problems (here: the underline is too short)
+    will look similar:
+
+        >>> source = '''
+        ... Headline
+        ... ======
+        ...
+        ... Thanks for watching!
+        ... '''
+        >>> html = ReST2HTML(source)
+        >>> print html
+        <div class="document" id="headline">
+        <h1 class="title">Headline</h1>
+        <BLANKLINE>
+        <p>Thanks for watching!</p>
+        </div>
+        
+    """
+    html, warnings = ReST2HTML_w_warnings(source_string)
+    return html