TFMA UI widgets fail to render in nbconvert HTML conversion

[kwlzn]

System information

• Have I written custom code (as opposed to using a stock example script
  provided in TensorFlow Model Analysis): N/A
• OS Platform and Distribution (e.g., Linux Ubuntu 16.04): CentOS 7
• TensorFlow Model Analysis installed from (source or binary): 0.27.0
• TensorFlow Model Analysis version (use command below): 0.27.0
• Python version: 3.7
• Jupyter Notebook version: JupyterLab 2.2.9
• Exact command to reproduce: nbconvert --to html

Describe the problem

Currently, TFDV, Tensorboard and other TFX UI elements that are rendered inline in a Jupyter notebook convert and are usable interactively in an HTML export/render of the notebook. This is highly useful when e.g. publishing a static HTML snapshot of a notebook for sharing with others.

However, the TFMA output widget seems to render as a blank output in this mode. This presents a UX gap in the E2E sharing of TFX pipelines inside Jupyter notebooks.

It is potentially related to #112 (which supercedes #56).

Source code / logs

eval_result = tfma.load_eval_result(eval_result_uri)
tfma.view.render_slicing_metrics(eval_result)

[ZxMYS]

It seems like the rendered view (its html) is not saved in the notebook. The output of the corresponding cell is an empty array in the notebook file.