Re: Plugin implementation help

"Igor Khavkine" <[email protected]> Tue, 18 May 2004 01:22:34 -0400

Newsgroups	gmane.comp.web.pyblosxom.user
Organization	Lycos Mail (http://www.mail.lycos.com:80)
Message-ID	<[email protected]>

--------- Original Message ---------
DATE: Mon, 17 May 2004 20:23:06
From: will guaraldi <[email protected]>
To: Igor Khavkine <[email protected]>
Cc: 

>On Mon, 17 May 2004, Igor Khavkine wrote:
>>
>> Ah. So at the point of cb_story(), the entry text has been processed and
>> has become an HTML fragment, and only the overall style of the blog page
>> has not yet been determined. Right?
>
>Yeah--you've totally got it.  All the template variables for the entry are
>available in the entry object.

Ok, thanks for your help. I managed to implement what
I wanted. I can now just put my images in the same
directory as the entry that uses them. In case anyone
else finds this little hack useful, I'm attaching
the code.

>> I'm still not very clear how to get the category of the story from
>> cb_story(args). I presume that I have to look in args['entry'], but what
>> am I looking for? How do I get the category and the filename?

For some reason args['entry']['story'] didn't work
for me. I had to use args['entry']['body'].

>Though I would grab the wbgdebug plugin at
>http://bluesock.org/~willg/dev/pyblosxom/ which enables you to force the
>debug renderer to kick in on your own blog when you do "?debug=yes".

Hm... This plugin didn't work out of the box for me,
but I havn't really checked why.

Igor



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showimg.py (text/x-python, 3.2 KB)

# vim: ts=2 sw=2 tw=72 expandtab
"""
This plugin changes references in <img/> tags so that entries could
refer to them without specifying the absolute path. The plugin requires
a special variable to be set in the config file: py['data_base_uri'].

If py['data_base_uri'] is set to '/~user/blog/data', then for an entry
in category 'cat' the tag '<img src="image.png"/>' would be replaced by
'<img src="/~user/blog/data/cat/image.png"/>'. Basically, with this
plugin, as long as py['datadir'] is web accessible, it is possible to
include images in entries by specifying their location relative to the
entry file.

One caveat is that <img/> replacement is done using an HTML parser, so
invalid HTML code produces errors which are not handled gracefully (yet).
"""

__author__ = "Igor Khavkine <k_igor_k AT lycos DOT com>"
__version__ = "0.1"

import Pyblosxom, os, re
from HTMLParser import HTMLParser

# global variables
base_uri = ""
data_dir = ""
category = ""

def relocate(uri):
  """
  This function checks whether the category-relative uri points to an
  actual file.

  @param uri: relative location of file with respect to the category
  @type uri: string
  """
  path = os.path.join(data_dir, category, uri)
  if os.path.exists(path):
    return base_uri + "/" + category + "/" + uri
  # more tests can go here
  else:
    return uri
  

class IMGReplacer(HTMLParser):
  """
  This class parses an HTML fragmet and replaces <img/> tags when
  possible.
  """
  filtered_text = ''
  def reset(self):
    filtered_text = ''
    HTMLParser.reset(self)

  def handle_starttag(self, tag, attrs):
    self.filtered_text += "<" + tag
    for (attr, val) in attrs:
      self.filtered_text += " " + attr + '="' + val.replace('"',r'\"') + '"'
    self.filtered_text += '>'

  def handle_startendtag(self, tag, attrs):
    self.filtered_text += "<" + tag
    for (attr, val) in attrs:
      if (tag == "img" and attr == "src"):
        val = relocate(val)
      self.filtered_text += " " + attr + '="' + val.replace('"',r'\"') + '"'
    self.filtered_text += '/>'

  def handle_endtag(self, tag):
    self.filtered_text += "</" + tag + ">"

  def handle_data(self, data):
    self.filtered_text += data

  def handle_charref(self, name):
    self.filtered_text += "&#" + name + ";"

  def handle_entityref(self, name):
    self.filtered_text += "&" + name + ";"

  def handle_comment(self, data):
    self.filtered_text += "<!--" + data + "-->"


def replace_img(text):
  """
  Replace relative references in <img/> tags by absolute ones.

  @param text: an HTML fragment
  @type text: string
  """
  ir = IMGReplacer()
  ir.feed(text)
  ir.close()
  return ir.filtered_text

def cb_story(args):
  """
  Story callback. It is run after the story has been processed and
  just before the blog page style is rendered.

  @param args: a dict with 'entry' Entry object
  @type args: dict
  """
  global category, data_dir, base_uri
  # set some global vars to be used in replaced paths
  entry = args['entry']
  data_dir = entry['datadir']
  base_uri = entry.get('data_base_uri', '')
  category = entry.get('absolute_path', '')
  # perhaps 'file_path' is also useful

  story = replace_img(entry['body'])
  entry['body'] = story
  
  return args