| # |
| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You under the Apache License, Version 2.0 |
| # (the "License"); you may not use this file except in compliance with |
| # the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # |
| |
| """For rendering pipeline graph in HTML-compatible format. |
| |
| This module is experimental. No backwards-compatibility guarantees. |
| """ |
| |
| from __future__ import absolute_import |
| from __future__ import division |
| from __future__ import print_function |
| |
| import abc |
| import os |
| import subprocess |
| |
| from future.utils import with_metaclass |
| |
| from apache_beam.utils.plugin import BeamPlugin |
| |
| |
| class PipelineGraphRenderer(with_metaclass(abc.ABCMeta, BeamPlugin)): |
| """Abstract class for renderers, who decide how pipeline graphs are rendered. |
| """ |
| |
| @classmethod |
| @abc.abstractmethod |
| def option(cls): |
| """The corresponding rendering option for the renderer. |
| """ |
| raise NotImplementedError |
| |
| @abc.abstractmethod |
| def render_pipeline_graph(self, pipeline_graph): |
| """Renders the pipeline graph in HTML-compatible format. |
| |
| Args: |
| pipeline_graph: (pipeline_graph.PipelineGraph) the graph to be rendererd. |
| |
| Returns: |
| unicode, str or bytes that can be expressed as HTML. |
| """ |
| raise NotImplementedError |
| |
| |
| class MuteRenderer(PipelineGraphRenderer): |
| """Use this renderer to mute the pipeline display. |
| """ |
| |
| @classmethod |
| def option(cls): |
| return 'mute' |
| |
| def render_pipeline_graph(self, pipeline_graph): |
| return '' |
| |
| |
| class TextRenderer(PipelineGraphRenderer): |
| """This renderer simply returns the dot representation in text format. |
| """ |
| |
| @classmethod |
| def option(cls): |
| return 'text' |
| |
| def render_pipeline_graph(self, pipeline_graph): |
| return pipeline_graph.get_dot() |
| |
| |
| class PydotRenderer(PipelineGraphRenderer): |
| """This renderer renders the graph using pydot. |
| |
| It depends on |
| 1. The software Graphviz: https://www.graphviz.org/ |
| 2. The python module pydot: https://pypi.org/project/pydot/ |
| """ |
| |
| @classmethod |
| def option(cls): |
| return 'graph' |
| |
| def render_pipeline_graph(self, pipeline_graph): |
| return pipeline_graph._get_graph().create_svg().decode("utf-8") # pylint: disable=protected-access |
| |
| |
| def get_renderer(option=None): |
| """Get an instance of PipelineGraphRenderer given rendering option. |
| |
| Args: |
| option: (str) the rendering option. |
| |
| Returns: |
| (PipelineGraphRenderer) |
| """ |
| if option is None: |
| if os.name == 'nt': |
| exists = subprocess.call(['where', 'dot.exe']) == 0 |
| else: |
| exists = subprocess.call(['which', 'dot']) == 0 |
| |
| if exists: |
| option = 'graph' |
| else: |
| option = 'text' |
| |
| renderer = [r for r in PipelineGraphRenderer.get_all_subclasses() |
| if option == r.option()] |
| if len(renderer) == 0: |
| raise ValueError() |
| elif len(renderer) == 1: |
| return renderer[0]() |
| else: |
| raise ValueError('Found more than one renderer for option: %s', |
| option) |