Source code for apache_beam.runners.interactive.display.pipeline_graph_renderer

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"""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


[docs]class PipelineGraphRenderer(with_metaclass(abc.ABCMeta, BeamPlugin)): """Abstract class for renderers, who decide how pipeline graphs are rendered. """
[docs] @classmethod @abc.abstractmethod def option(cls): """The corresponding rendering option for the renderer. """ raise NotImplementedError
[docs] @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
[docs]class MuteRenderer(PipelineGraphRenderer): """Use this renderer to mute the pipeline display. """
[docs] @classmethod def option(cls): return 'mute'
[docs] def render_pipeline_graph(self, pipeline_graph): return ''
[docs]class TextRenderer(PipelineGraphRenderer): """This renderer simply returns the dot representation in text format. """
[docs] @classmethod def option(cls): return 'text'
[docs] def render_pipeline_graph(self, pipeline_graph): return pipeline_graph.get_dot()
[docs]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/ """
[docs] @classmethod def option(cls): return 'graph'
[docs] def render_pipeline_graph(self, pipeline_graph): return pipeline_graph._get_graph().create_svg().decode("utf-8") # pylint: disable=protected-access
[docs]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)