Added os.path.join() to a few filesystem related string operations.

[cmless] / bin / misc.py

# (c) 2017 Aaron Taylor <ataylor at subgeniuskitty dot com>
# See LICENSE file for copyright and license details.

# Python imports
import os, sys, subprocess, configparser

# CMless imports
import debug, config, template

def load_file(path):
   """Open the text file at 'path' and return the contents as a string."""
   try:
       with open(path) as f:
           contents = f.read()
   except:
       if debug.print_to_browser: print("Unable to open " + path + " for reading.")
       sys.exit("Unable to open " + path + " for reading.")
   return contents

def process_markup(text):
   """Execute external markup processor and return processed 'text'.

   Markup processor is specified by config.markup_processor variable
   and should accept markup on stdin while returning HTML on stdout.
   """
   try:
       p = subprocess.Popen(config.markup_processor,
               stdout=subprocess.PIPE,stdin=subprocess.PIPE)
   except:
       if debug.print_to_browser: print("Unable to open markup processor: " +
               config.markup_processor)
       sys.exit("Unable to open markup processor: " + config.markup_processor)
   text = p.communicate(text.encode('UTF-8'))[0]
   return(text.decode('UTF-8'))

def strip_page_metadata(content):
   """Strip metadata from the beginning of 'content' and return whatever remains."""
   keyword = template.add_delimiter("END_PAGE_METADATA")
   index = content.find(keyword)
   if index != -1:
       return content[index+len(keyword):]
   else:
       return content

def lookup_current_metadata(key):
   """Wrapper for lookup_file_metadata() supplying the current REQUEST_URI as 'file'."""
   file = os.path.join(config.site_data_prefix + os.environ['REQUEST_URI'] +
           config.markup_file_extension)
   return lookup_file_metadata(key,file)

def lookup_file_metadata(key,file):
   """Read 'key' metadata in 'file' and return corresponding value.

   Assumes key is contained in the [DEFAULT] category.
   Returns empty string if key is not present.
   """
   page_file = load_file(file)

   # Extract just the metadata block so we can pass it to ConfigParser.
   keyword_begin = template.add_delimiter("BEGIN_PAGE_METADATA")
   keyword_end = template.add_delimiter("END_PAGE_METADATA")
   index = page_file.find(keyword_end)
   if index != -1:
       page_file = page_file[len(keyword_begin):index]
   else:
       # ConfigParser will accept an empty string so use that as fallback.
       page_file = ""

   page_metadata = configparser.ConfigParser()
   page_metadata.read_string(page_file)

   if 'DEFAULT' in page_metadata and key in page_metadata['DEFAULT']:
       return page_metadata['DEFAULT'][key]
   else:
       # An empty string is technically a valid value for a key but we will
       # overload it as also indicating 'key' wasn't present since a key
       # without a value is functionally equivalent to no key at all for our
       # purposes.
       return ""