data model visualization is broken

[nhoening]

The command make show-data-model seems to have stopped working - I suspect that a dependency upgrade has caused this, maybe in the PIL package. Error message is below.
Some debugging might be helpful.

I could get the image creation going by removing the command argument from Image.open(iostream).show(). I'd look up why this parameter is gone. Is this function now better at guessing how to show a plot? Maybe we should remove FALLBACK_VIEWER_CMD ....

Also make a changelog entry!

./flexmeasures/data/scripts/visualize_data_model.py --uml --dev
DEBUG is on
CREATING UML CODE DIAGRAM ...
Finding all the relevant mappers in our model...
Relevant tables: ['role', 'account', 'account_role', 'fm_user', 'data_source', 'latest_task_run', 'generic_asset_type', 'generic_asset', 'sensor', 'timed_belief', 'timed_value']
Relevant models: {'latesttaskrun': <class 'flexmeasures.data.models.task_runs.LatestTaskRun'>, 'datasource': <class 'flexmeasures.data.models.data_sources.DataSource'>, 'genericasset': <class 'flexmeasures.data.models.generic_assets.GenericAsset'>, 'genericassettype': <class 'flexmeasures.data.models.generic_assets.GenericAssetType'>, 'market': <class 'flexmeasures.data.models.markets.Market'>, 'markettype': <class 'flexmeasures.data.models.markets.MarketType'>, 'price': <class 'flexmeasures.data.models.markets.Price'>, 'sensor': <class 'flexmeasures.data.models.time_series.Sensor'>, 'timedbelief': <class 'flexmeasures.data.models.time_series.TimedBelief'>, 'asset': <class 'flexmeasures.data.models.assets.Asset'>, 'assettype': <class 'flexmeasures.data.models.assets.AssetType'>, 'power': <class 'flexmeasures.data.models.assets.Power'>, 'user': <class 'flexmeasures.data.models.user.User'>, 'annotation': <class 'flexmeasures.data.models.annotations.Annotation'>, 'weather': <class 'flexmeasures.data.models.weather.Weather'>, 'weathersensor': <class 'flexmeasures.data.models.weather.WeatherSensor'>, 'weathersensortype': <class 'flexmeasures.data.models.weather.WeatherSensorType'>, 'account': <class 'flexmeasures.data.models.user.Account'>, 'accountannotationrelationship': <class 'flexmeasures.data.models.annotations.AccountAnnotationRelationship'>, 'accountrole': <class 'flexmeasures.data.models.user.AccountRole'>, 'role': <class 'flexmeasures.data.models.user.Role'>, 'rolesaccounts': <class 'flexmeasures.data.models.user.RolesAccounts'>, 'rolesusers': <class 'flexmeasures.data.models.user.RolesUsers'>, 'sensorannotationrelationship': <class 'flexmeasures.data.models.annotations.SensorAnnotationRelationship'>}
Loading class LatestTaskRun ...
Loading class DataSource ...
Loading class GenericAsset ...
Loading class GenericAssetType ...
Loading class Sensor ...
Loading class TimedBelief ...
Loading class User ...
Loading class Account ...
Loading class AccountRole ...
Loading class Role ...
Creating diagram ...
Creating the pydot graph object...
Creating PNG stream ...
Showing image ...
(fallback viewer is gwenview)
Traceback (most recent call last):
  File "/home/nicolas/workspace/seita/flexmeasures/./flexmeasures/data/scripts/visualize_data_model.py", line 286, in <module>
    create_uml_pic(store=args.store, dev=args.dev)
  File "/home/nicolas/workspace/seita/flexmeasures/./flexmeasures/data/scripts/visualize_data_model.py", line 103, in wrapper
    return func(*args, **kwargs)
  File "/home/nicolas/workspace/seita/flexmeasures/./flexmeasures/data/scripts/visualize_data_model.py", line 195, in create_uml_pic
    show_image(graph, fb_viewer_command=FALLBACK_VIEWER_CMD)
  File "/home/nicolas/workspace/seita/flexmeasures/./flexmeasures/data/scripts/visualize_data_model.py", line 103, in wrapper
    return func(*args, **kwargs)
  File "/home/nicolas/workspace/seita/flexmeasures/./flexmeasures/data/scripts/visualize_data_model.py", line 224, in show_image
    Image.open(iostream).show(command=fb_viewer_command)
TypeError: show() got an unexpected keyword argument 'command'

[nhoening]

It seems indeed that PIL changed and now is making its own guess how to render an image on the various platforms, see here.

The UnixViewer and its various subclasses are how it gets decided on Linux, but they also have classes for Windows and Mac.