[jaladh-singhal]

Fixes FIREFLY-2076

A period (.) in a tbl_id passed to show_table() caused the table's chart and coverage image not to display. The cause is in Firefly's JS code: some reducers use IDs as lodash string paths (lodash set/get treat a dot as a nesting separator), so my.table gets stored under my → table instead of as one key. Rather than fixing every such call in Firefly, the python client now rejects these IDs early with a clear error.

• Added validate_id() in fc_utils.py, which raises a ValueError if an ID contains a period (suggesting _ instead)
• Called it in every method that takes a user-supplied ID that Firefly code uses as a string path:
  • tbl_id: show_table, fetch_table (the table's default chart ID is 'default-' + tbl_id, which is why the chart disappeared)
  • chartId: show_chart (ChartsCntlr.js)
  • plot_id: show_fits_image/show_fits, show_fits_3color, show_hips, show_image_or_hips (RegionPlot.js, ImageLineBasedFootprint.js: region/footprint layers on the plot can break)
• Noted the restriction in each affected parameter's docstring

Other IDs (viewer_id, group_id, cell_id, region_layer_id, mask_id, extension IDs) are only used as array paths or plain keys in Firefly, so they're safe.

Testing

Install Python package from this branch:

pip install git+https://github.com/Caltech-IPAC/firefly_client@FIREFLY-2076-period-in-id-bug

1. Run examples/reference-guide.ipynb and change any tbl_id or plot_id to contain a period (e.g. cutout_image_plot_id = 'wise.cutout'). That cell should raise ValueError: plot_id 'wise.cutout' must not contain a period ('.'); use another character such as '_' instead, without sending anything to Firefly.
2. Revert the ID to use _ or -. The notebook should run as before, with tables showing their default chart and coverage image.

[stargaser]

The code changes work. I was only having trouble with tbl_ids originally, not with plot_ids. If plot_ids with periods don't cause problems, can we have them? In my scripts I use filenames like ztf_20171101229433_907017_zr_c16_o_q3_sciimg_ra338.9963_dec33.9586_asec600.fits so with this PR I'll have to change those all to underscores.