lodel2_mirror/lodel/settings/settings_loader.py

#-*- coding: utf-8 -*-
import configparser
import os
import glob
import copy

from lodel.settings.utils import *

   
##@brief Merges and loads configuration files
class SettingsLoader(object):
    
    ## To avoid the DEFAULT section whose values are found in all sections, we
    # have to give it an unsual name
    DEFAULT_SECTION = 'lodel2_default_passaway_tip'

    ##@brief Constructor
    # @param conf_path str : conf.d path
    def __init__(self,conf_path):
        self.__conf_path=conf_path
        self.__conf_sv=dict()
        self.__conf=self.__merge()
    
    ##@brief Lists and merges files in settings_loader.conf_path
    # @return dict()
    def __merge(self):
        conf = dict()
        l_dir = glob.glob(self.__conf_path+'/*.ini')  

        for f_ini in l_dir:  
            config = configparser.ConfigParser(default_section = self.DEFAULT_SECTION ,interpolation=None)
            config.read(f_ini)
            for section in [ s for s in config if s != self.DEFAULT_SECTION ]:
                if section not in conf:
                    conf[section] = dict()
                for param in config[section]:
                    if param not in conf[section]: 
                        conf[section][param] = config[section][param]
                        self.__conf_sv[section + ':' + param]=f_ini
                    else:
                        raise SettingsError("Error redeclaration of key %s in section %s. Found in %s and %s" % (
            section,
            param,
            f_ini,
            self.__conf_sv[section + ':' + param]))
        return conf
    
    ##@brief Returns option if exists default_value else and validates
    # @param section str : name of the section
    # @param keyname str
    # @param validator callable : takes one argument value and raises validation fail
    # @param default_value *
    # @param mandatory bool
    # @return the option
    def getoption(self,section,keyname,validator,default_value=None,mandatory=False):
        conf=copy.copy(self.__conf)
        sec=conf[section]
        if keyname in sec:
            optionstr=sec[keyname]
            option=validator(sec[keyname])
            try:
                del self.__conf_sv[section + ':' + keyname]
            except KeyError: #allready fetched
                pass
            return option
        elif mandatory:
             raise SettingsError("Default value mandatory for option %s" % keyname)
        else:
             return default_value
    
    ##@brief Returns the section to be configured
    # @param section_prefix str
    # @param default_section str
    # @return the section as dict()
    def getsection(self,section_prefix,default_section=None):
        conf=copy.copy(self.__conf)
       
        sections=[]
        if section_prefix in conf:
            sections.append(section_prefix)
        for sect_names in conf:
            if sect_names in sections:
                pass
            elif sect_names.startswith(section_prefix + '.'):
                sections.append(sect_names)
        if sections == [] and default_section: 
             sections.append(section_prefix + '.' + default_section)
        elif sections == []:
            raise NameError("Not existing settings section : %s" % section__prefix)
            
        return sections;
    
    ## @brief Returns invalid settings
    #
    # This method returns all the settings that was not fecthed by 
    # getsection() method. For the Settings object it allows to know
    # the list of invalids settings keys
    # @return a dict with SECTION_NAME+":"+KEY_NAME as key and the filename
    # where the settings was found as value
    def getremains(self):
        return self.__conf_sv