Source Code for Module fuzz.visualization

  1  """\ 
  2  Visualization manager for FuzzPy. This submodule allows the dispatch of any 
  3  supported fuzzpy datatypes to an arbitrary visualization plugin. All available 
  4  visualization plugins are located in the L{visplugins} submodule. 
  5   
  6  The manager provides a helper function to discover installed plugins as well 
  7  as a visualization backend factory. 
  8   
  9  @author: Xavier Spriet 
 10  @contact: linkadmin@gmail.com 
 11  @license: LGPL-3 
 12  """ 
 13   
 14  import warnings 
 15   
 16  from . import visplugins 
 17   
 18 -class VisManager(object): 
 19      """\ 
 20      Visualization plugin factory class. 
 21           
 22      Provides plugin management methods and a helper method to dispatch 
 23      a FuzzPy object to a plugin. 
 24      """ 
 25       
 26      @staticmethod 
 27 -    def get_supported_plugins(datatype=None): 
 28          """\ 
 29          Returns a list of plugins supported by the current system. 
 30           
 31          If L{datatype} is specified, try to find supported plugins that can 
 32          be used to represent the specified datatype. Otherwise, return a list 
 33          of all plugins that can run on that system. 
 34           
 35          If any type of exception is raised during the C{is_supported()} call, 
 36          the plugin will B{not} be included in the resulting list. 
 37           
 38          @param datatype: fuzzpy datatype to look for supported plugins. 
 39          @type datatype: C{str} 
 40          @rtype: C{list} 
 41          @return: list of plugins that can run in the current environment 
 42          """ 
 43          supported = [] 
 44           
 45          for plugin in visplugins.__all__: 
 46              # Try to import the plugin 
 47              try: 
 48                  plugin_mod = __import__("visplugins.%s" % plugin, 
 49                          globals(), locals(), fromlist=[plugin]) 
 50              except ImportError as ex: 
 51                  warnings.warn(ex) 
 52                  continue 
 53                   
 54              # Extract plugin class name (or raise AttributeError) 
 55              if not getattr(plugin_mod, 'VIS_PLUGIN'): 
 56                  raise AttributeError(("Plugin %s is missing VIS_PLUGIN " 
 57                                        "property") % plugin) 
 58              plugin_class = getattr(plugin_mod, plugin_mod.VIS_PLUGIN) 
 59               
 60              if (getattr(plugin_class, 'is_supported')() == True) and \ 
 61                  (datatype in [None] + getattr(plugin_mod, 'VIS_TYPES')): 
 62                  supported.append(plugin) 
 63   
 64          return supported 
 65       
 66      @staticmethod 
 67 -    def create_backend(obj, plugin=None, *args, **kwargs): 
 68          """\ 
 69          Visualization plugin factory method. 
 70           
 71          Returns a new instance of the appropriate visualization plugin. 
 72          If no 'plugin' argument is specified as the preferred visualization 
 73          backend, the first plugin that supports visualization for 'obj's 
 74          class name will be used as the backend. 
 75           
 76          @param obj: Object to draw 
 77          @type obj: Object 
 78          @param plugin: Name of the plugin to use 
 79          @type plugin: C{str} 
 80          @returns: The return value of the plugin's visualize() method 
 81          @rtype: C{tuple} (format, payload) 
 82          """ 
 83           
 84          # Pick a supported plugin if none is specified 
 85          if None == plugin: 
 86              try: 
 87                  plugin = VisManager.get_supported_plugins(obj.__class__)[0] 
 88              except IndexError: 
 89                  raise ImportError(("Unable to load any plugin to handle the " 
 90                                     "specified object type")) 
 91           
 92          plugin_mod = __import__("visplugins.%s" % plugin, globals(), locals(), 
 93                  fromlist=[plugin]) 
 94           
 95          # Extract plugin class name 
 96          plugin_name = getattr(plugin_mod, 'VIS_PLUGIN') 
 97           
 98          return getattr(plugin_mod, plugin_name)\ 
 99              (obj=obj, args=args, kwargs=kwargs) 
100