# -*- coding: utf-8 -*-
__author__ = "Ngoc Huynh Bao"
__email__ = "ngoc.huynh.bao@nmbu.no"
from tensorflow.keras.layers import Layer
from tensorflow.keras.models import model_from_config
from ..utils import Singleton
from .activations import Activations
[docs]class Layers(metaclass=Singleton):
"""
A singleton that contains all the registered customized layers
"""
def __init__(self):
self._layers = {}
[docs] def register(self, key, layer):
if not issubclass(layer, Layer):
raise ValueError(
"The customized layer has to be a subclass"
+ " of keras.layers.Layer"
)
if key in self._layers:
raise KeyError(
"Duplicated key, please use another key name for this layer"
)
else:
self._layers[key] = layer
[docs] def unregister(self, key):
if key in self._layers:
del self._layers[key]
@property
def layers(self):
return self._layers
[docs]def register_layer(key, layer):
"""
Register the customized layer.
If the key name is already registered, it will raise a KeyError exception
Parameters
----------
key : str
The unique key-name of the layer
layer : tensorflow.keras.layers.Layer
The customized layer class
"""
Layers().register(key, layer)
[docs]def unregister_layer(key):
"""
Remove the registered layer with the key-name
Parameters
----------
key : str
The key-name of the layer to be removed
"""
Layers().unregister(key)
[docs]def layer_from_config(config):
if 'class_name' not in config:
raise ValueError('class_name is needed to define layer')
if 'config' not in config:
# auto add empty config for layer with only class_name
config['config'] = {}
if 'name' not in config['config'] and 'name' in config:
config['config']['name'] = config['name']
return model_from_config(
config,
custom_objects={**Layers().layers,
**Activations().activations})