Level 14: custom data loader

Continuing from level 13, moban since v0.4.0 allows data loader extension. Due to the new capability overrides key word can override any data format:

overrides: yours.custom

or simple use .custom data instead of .yaml data.

However, you will need to provide a data loader for .custom yourselves.


Please change directory to docs/level-14-custom-data-loader directory.

In this tutorial, a custom data loader was provided to show case its dataloader extension. Here is the mobanfile:

    - custom-data-loader
  template: a.template
  - output: a.output
    configuration: child.custom
  - output: b.output
    configuration: override_custom.yaml

custom-data-loader is a directory where custom.py lives. The protocol is that the custom loader register itself to a file extension and return a data dictionary confirming mobanfile schema. On call, moban will provide an absolute file name for your loader to work on.

Here is the code to do the registration:

@PluginInfo(constants.DATA_LOADER_EXTENSION, tags=["custom"])

In order to evaluate, you can simply type:

$ moban
$ cat a.output

world from child.cusom

shijie from parent.json

$ cat b.output

world from override_custom.yaml

shijie from parent.custom



Python 2 dictates the existence of __init__.py in the plugin directory. Otheriwse your plugin won’t load