cpython/Lib/idlelib/configHandler.py

##---------------------------------------------------------------------------##
##
## idle - configuration data handler, based on and replacing IdleConfig.py 
## elguavas
## 
##---------------------------------------------------------------------------##
"""
Provides access to configuration information
"""

import os
import sys
from ConfigParser import ConfigParser, NoOptionError, NoSectionError

class IdleConfParser(ConfigParser):
    """
    A ConfigParser specialised for idle configuration file handling
    """
    def __init__(self, cfgFile, cfgDefaults=None):
        """
        cfgFile - string, fully specified configuration file name
        """
        self.file=cfgFile
        ConfigParser.__init__(self,defaults=cfgDefaults)
    
    def Get(self, section, option, default=None, type=None):
        """
        Get an option value for given section/option or return default.
        If type is specified, return as type.
        """
        if type=='bool': 
            getVal=self.getboolean
        elif type=='int': 
            getVal=self.getint
        else: 
            getVal=self.get
        if self.has_option(section,option):
            #return getVal(section, option, raw, vars)
            return getVal(section, option)
        else:
            return default

    def GetOptionList(self,section):
        """
        Get an option list for given section
        """
        if self.has_section:
            return self.options(section)
        else:  #return a default value
            return []

    def Load(self):
        """ 
        Load the configuration file from disk 
        """
        self.read(self.file)
        
class IdleUserConfParser(IdleConfParser):
    """
    IdleConfigParser specialised for user configuration handling
    """
    def Save(self):
        """
        write loaded user configuration file back to disk
        """
        # this is a user config, it can be written to disk
        self.write()

class IdleConf:
    """
    holds config parsers for all idle config files:
    default config files
        (idle install dir)/config-main.def
        (idle install dir)/config-extensions.def
        (idle install dir)/config-highlight.def
        (idle install dir)/config-keys.def
    user config  files
        (user home dir)/.idlerc/idle-main.cfg
        (user home dir)/.idlerc/idle-extensions.cfg
        (user home dir)/.idlerc/idle-highlight.cfg
        (user home dir)/.idlerc/idle-keys.cfg
    """
    def __init__(self):
        self.defaultCfg={}
        self.userCfg={}
        self.cfg={}
        self.CreateConfigHandlers()
        self.LoadCfgFiles()
        #self.LoadCfg()
            
    def CreateConfigHandlers(self):
        """
        set up a dictionary config parsers for default and user 
        configurations respectively
        """
        #build idle install path
        if __name__ != '__main__': # we were imported
            idledir=os.path.dirname(__file__)
        else: # we were exec'ed (for testing only)
            idledir=os.path.abspath(sys.path[0])
        #print idledir
        try: #build user home path
            userdir = os.environ['HOME'] #real home directory
        except KeyError:
            userdir = os.getcwd() #hack for os'es without real homedirs
        userdir=os.path.join(userdir,'.idlerc')
        #print userdir
        if not os.path.exists(userdir):
            os.mkdir(userdir)
        configTypes=('main','extensions','highlight','keys')
        defCfgFiles={}
        usrCfgFiles={}
        for cfgType in configTypes: #build config file names
            defCfgFiles[cfgType]=os.path.join(idledir,'config-'+cfgType+'.def')                    
            usrCfgFiles[cfgType]=os.path.join(userdir,'idle-'+cfgType+'.cfg')                    
        for cfgType in configTypes: #create config parsers
            self.defaultCfg[cfgType]=IdleConfParser(defCfgFiles[cfgType])
            self.userCfg[cfgType]=IdleUserConfParser(usrCfgFiles[cfgType])
    
    def GetOption(self, configType, section, option, default=None, type=None):
        """
        Get an option value for given config type and given general 
        configuration section/option or return a default. If type is specified,
        return as type. Firstly the user configuration is checked, with a 
        fallback to the default configuration, and a final 'catch all' 
        fallback to a useable passed-in default if the option isn't present in 
        either the user or the default configuration.
        configType must be one of ('main','extensions','highlight','keys')
        """
        if self.userCfg[configType].has_option(section,option):
            return self.userCfg[configType].Get(section, option, type=type)
        elif self.defaultCfg[configType].has_option(section,option):
            return self.defaultCfg[configType].Get(section, option, type=type)
        else:
            return default
    
    def GetSectionList(self, configSet, configType):
        """
        Get a list of sections from either the user or default config for 
        the given config type.
        configSet must be either 'user' or 'default' 
        configType must be one of ('extensions','highlight','keys')
        """
        if not (configType in ('extensions','highlight','keys')):
            raise 'Invalid configType specified'
        if configSet == 'user':
            cfgParser=self.userCfg[configType]
        elif configSet == 'default':
            cfgParser=self.defaultCfg[configType]
        else:
            raise 'Invalid configSet specified'
        
        return cfgParser.sections()
    
    def GetHighlight(self, theme, element):
        fore = self.GetOption('highlight', theme, element + "-foreground")
        back = self.GetOption('highlight', theme, element + "-background")
        return {"foreground": fore,
                "background": back}

    def GetTheme(self, name=None):
        """
        Gets the requested theme or returns a final fallback theme in case 
        one can't be obtained from either the user or default config files.
        """
        pass
    
    def GetKeys(self, name=None):
        """
        Gets the requested keybindings or returns a final fallback keybinding 
        set in case one can't be obtained from either the user or default 
        config files.
        """
        pass
    
    def LoadCfgFiles(self):
        """ 
        load all configuration files.
        """
        for key in self.defaultCfg.keys():
            self.defaultCfg[key].Load()                    
            self.userCfg[key].Load() #same keys                    

    def SaveUserCfgFiles(self):
        """
        write all loaded user configuration files back to disk
        """
        for key in self.userCfg.keys():
            self.userCfg[key].Save()    

idleConf=IdleConf()

### module test
if __name__ == '__main__':
    def dumpCfg(cfg):
        print '\n',cfg,'\n'
        for key in cfg.keys():
            sections=cfg[key].sections()
            print key
            print sections
            for section in sections:
                options=cfg[key].options(section)
                print section    
                print options
                for option in options:
                    print option, '=', cfg[key].Get(section,option)
    dumpCfg(idleConf.defaultCfg)
    dumpCfg(idleConf.userCfg)
    print idleConf.userCfg['main'].Get('Theme','name')
    #print idleConf.userCfg['highlight'].GetDefHighlight('Foo','normal')