Add online commenting support

This patch adds support for online commenting. A new template
``com_form.html`` to customize the commenting form is added. Online
commenting is only available if ``enable_comments`` is True, and you need
to let the web server write to the ``comments_path`` directory.

Note that this patch exposes the race in the CommentDB.save() method
(described in the previous commit), but since this event is unlikely
enough, we don't care at the moment and can be fixed later if needed.

diff --git a/blitiri.cgi b/blitiri.cgi
index 161449a1f73abbc961851d88d851434c2aa77679..22532edc1c28ee5b578a9d019561ed10f2c17efd 100755 (executable)
--- a/blitiri.cgi
+++ b/blitiri.cgi
@@ -48,6 +48,8 @@ encoding = "utf8"
 
 import sys
 import os
+import errno
+import shutil
 import time
 import datetime
 import calendar
@@ -150,6 +152,47 @@ default_comment_footer = """
 </div>
 """
 
+default_comment_form = """
+<div class="comform">
+<a name="comment" />
+<h3 class="comform"><a href="#comment">Your comment</a></h3>
+<div class="comforminner">
+<form method="%(form_method)s" action="%(form_action)s">
+<div class="comformauthor">
+  <label for="comformauthor">Your name</label>
+  <input type="text" class="comformauthor" id="comformauthor"
+         name="comformauthor" />
+</div>
+<div class="comformlink">
+  <label for="comformlink">Your link
+    <span class="comformoptional">(optional, will be published)</span></label>
+  <input type="text" class="comformlink" id="comformlink"
+         name="comformlink" />
+  <div class="comformhelp">
+    like <span class="formurlexample">http://www.example.com/</span>
+    or <span class="formurlexample">mailto:you@example.com</span>
+  </div>
+</div>
+<div class="comformbody">
+  <label for="comformbody" class="comformbody">The comment</label>
+  <textarea class="comformbody" id="comformbody" name="comformbody" rows="15"
+            cols="80"></textarea>
+  <div class="comformhelp">
+    in
+    <a href="http://docutils.sourceforge.net/docs/user/rst/quickref.html">\
+RestructuredText</a> format, please
+  </div>
+</div>
+<div class="comformsend">
+  <button type="submit" class="comformsend" id="comformsend" name="comformsend">
+    Send comment
+  </button>
+</div>
+</form>
+</div>
+</div>
+"""
+
 
 # Default CSS
 default_css = """
@@ -234,6 +277,57 @@ div.comment {
        margin-bottom: 1em;
 }
 
+div.comforminner {
+       margin-left: 2em;
+}
+
+div.comform {
+       margin-left: 1em;
+       margin-bottom: 1em;
+}
+
+div.comform label {
+       display: block;
+       border-bottom: 1px solid #99C;
+       margin-top: 0.5em;
+       clear: both;
+}
+
+div.comform span.comformoptional {
+       font-size: xx-small;
+       color: #666;
+}
+
+div.comform input {
+       font-size: small;
+       width: 99%;
+}
+
+div.comformhelp {
+       font-size: xx-small;
+       text-align: right;
+       float: right;
+}
+
+span.formurlexample {
+       color: #111;
+       background-color: #EEF;
+       font-family: monospace;
+       padding-left: 0.2em;
+       padding-right: 0.2em;
+}
+
+textarea.comformbody {
+       font-family: monospace;
+       font-size: small;
+       width: 99%;
+       height: 15em;
+}
+
+button.comformsend {
+       margin-top: 0.5em;
+}
+
 hr {
        float: left;
        height: 2px;
@@ -270,11 +364,20 @@ def rst_to_html(rst):
        settings = {
                'input_encoding': encoding,
                'output_encoding': 'utf8',
+               'halt_level': 1,
+               'traceback':  1,
        }
        parts = publish_parts(rst, settings_overrides = settings,
                                writer_name = "html")
        return parts['body'].encode('utf8')
 
+def valid_rst(rst):
+       try:
+               rst_to_html(rst)
+               return True
+       except:
+               return False
+
 def sanitize(obj):
        if isinstance(obj, basestring):
                return cgi.escape(obj, True)
@@ -348,6 +451,13 @@ class Templates (object):
                return self.get_template(
                        'com_footer', default_comment_footer, comment.to_vars())
 
+       def get_comment_form(self, article, method, action):
+               vars = article.to_vars()
+               vars['form_method'] = method
+               vars['form_action'] = action
+               return self.get_template(
+                       'com_footer', default_comment_form, vars)
+
 
 class Comment (object):
        def __init__(self, article, number, created = None):
@@ -385,6 +495,14 @@ class Comment (object):
        raw_content = property(fget = get_raw_content)
 
 
+       def set(self, author, raw_content, link = '', created = None):
+               self.loaded = True
+               self._author = author
+               self._raw_content = raw_content
+               self._link = link
+               self.created = created or datetime.datetime.now()
+
+
        def load(self):
                filename = os.path.join(comments_path, self.article.uuid,
                                        str(self.number))
@@ -408,6 +526,19 @@ class Comment (object):
                self._raw_content = ''.join(raw[count + 1:])
                self.loaded = True
 
+       def save(self):
+               filename = os.path.join(comments_path, self.article.uuid,
+                                       str(self.number))
+               try:
+                       f = open(filename, 'w')
+                       f.write('Author: %s\n' % self.author)
+                       f.write('Link: %s\n' % self.link)
+                       f.write('\n')
+                       f.write(self.raw_content)
+               except:
+                       return
+
+
        def to_html(self):
                return rst_to_html(self.raw_content)
 
@@ -533,6 +664,13 @@ class Article (object):
                return cmp(self.title, other.title)
 
 
+       def add_comment(self, author, raw_content, link = ''):
+               c = Comment(self, len(self.comments))
+               c.set(author, raw_content, link)
+               self.comments.append(c)
+               return c
+
+
        def load(self):
                # XXX this tweak is only needed for old DB format, where
                # article's paths started with a slash
@@ -690,9 +828,14 @@ class ArticleDB (object):
 #
 
 
-def render_html(articles, db, actyear = None, show_comments = False):
+def render_html(articles, db, actyear = None, show_comments = False,
+               redirect =  None):
+       if redirect is not None:
+               print 'Status: 303 See Other\r\n',
+               print 'Location: %s\r\n' % redirect,
+       print 'Content-type: text/html; charset=utf-8\r\n',
+       print '\r\n',
        template = Templates(templates_path, db, actyear)
-       print 'Content-type: text/html; charset=utf-8\n'
        print template.get_main_header()
        for a in articles:
                print template.get_article_header(a)
@@ -706,6 +849,8 @@ def render_html(articles, db, actyear = None, show_comments = False):
                                print template.get_comment_header(c)
                                print c.to_html()
                                print template.get_comment_footer(c)
+                       print template.get_comment_form(a, 'post',
+                                       blog_url + '/comment/' + a.uuid)
        print template.get_main_footer()
 
 def render_artlist(articles, db, actyear = None):
@@ -786,6 +931,7 @@ def handle_cgi():
        style = False
        post = False
        artlist = False
+       comment = False
 
        if os.environ.has_key('PATH_INFO'):
                path_info = os.environ['PATH_INFO']
@@ -794,8 +940,9 @@ def handle_cgi():
                tag = path_info.startswith('/tag/')
                post = path_info.startswith('/post/')
                artlist = path_info.startswith('/list')
+               comment = path_info.startswith('/comment/') and enable_comments
                if not style and not atom and not post and not tag \
-                               and not artlist:
+                               and not comment and not artlist:
                        date = path_info.split('/')[1:]
                        try:
                                if len(date) > 1 and date[0]:
@@ -814,6 +961,12 @@ def handle_cgi():
                        t = t.replace('/', '')
                        t = urllib.unquote_plus(t)
                        tags = set((t,))
+               elif comment:
+                       uuid = path_info.replace('/comment/', '')
+                       uuid = uuid.replace('/', '')
+                       author = form.getfirst('comformauthor', '')
+                       link = form.getfirst('comformlink', '')
+                       body = form.getfirst('comformbody', '')
 
        db = ArticleDB(os.path.join(data_path, 'db'))
        if atom:
@@ -828,6 +981,21 @@ def handle_cgi():
                articles = db.get_articles()
                articles.sort(cmp = Article.title_cmp)
                render_artlist(articles, db)
+       elif comment:
+               author = author.strip().replace('\n', ' ')
+               link = link.strip().replace('\n', ' ')
+               body = body.strip()
+               article = db.get_article(uuid)
+               redirect = blog_url + '/post/' + uuid + '#comment'
+               if author and body and valid_rst(body):
+                       c = article.add_comment(author, body, link)
+                       c.save()
+                       cdb = CommentDB(article)
+                       cdb.comments = article.comments
+                       cdb.save()
+                       redirect += '-' + str(c.number)
+               render_html( [article], db, year, enable_comments,
+                               redirect = redirect )
        else:
                articles = db.get_articles(year, month, day, tags)
                articles.sort(reverse = True)
@@ -867,6 +1035,17 @@ def handle_cmd():
                                return 1
                db.articles.append(article)
                db.save()
+               if enable_comments:
+                       comment_dir = os.path.join(comments_path, article.uuid)
+                       try:
+                               os.mkdir(comment_dir, 0775)
+                       except OSError, e:
+                               if e.errno != errno.EEXIST:
+                                       print "Error: can't create comments " \
+                                               "directory %s (%s)" \
+                                                       % (comment_dir, e)
+                               # otherwise is probably a removed and re-added
+                               # article
        elif cmd == 'rm':
                article = Article(art_path)
                for a in db.articles:
@@ -875,8 +1054,12 @@ def handle_cmd():
                else:
                        print "Error: no such article"
                        return 1
+               if enable_comments:
+                       r = raw_input('Remove comments [y/N]? ')
                db.articles.remove(a)
                db.save()
+               if enable_comments and r.lower() == 'y':
+                       shutil.rmtree(os.path.join(comments_path, a.uuid))
        elif cmd == 'update':
                article = Article(art_path)
                for a in db.articles: