Handle ?_labels=on

[simonw]

Handle ?_labels=on

[simonw]

This fix fails if the first row of the returned data has any null values for anything that should have been expanded - e.g.:

{
  "rowid": 1,
  "TreeID": 141565,
  "qLegalStatus": {
    "value": 1,
    "label": "Permitted Site"
  },
  "qSpecies": {
    "value": 1,
    "label": "Myoporum laetum :: Myoporum"
  },
  "qAddress": "501X Baker St",
  "SiteOrder": 1,
  "qSiteInfo": {
    "value": 1,
    "label": "Sidewalk: Curb side : Cutout"
  },
  "PlantType": {
    "value": 1,
    "label": "Tree"
  },
  "qCaretaker": {
    "value": 1,
    "label": "Private"
  },
  "qCareAssistant": null,
  "PlantDate": "07/21/1988 12:00:00 AM",
  "DBH": 21,
  "PlotSize": "Width 0ft",
  "PermitNotes": "Permit Number 25401",
  "XCoord": 6000609,
  "YCoord": 2110829,
  "Latitude": 37.7759676911831,
  "Longitude": -122.441396661871,
  "Location": "(37.7759676911831, -122.441396661871)"
}

Because this first row has "qCareAssistant": null the code will not correctly identify that as a column which has a label, and hence attempting to graph against that column will fail.

[simonw]

I can fix this by inspecting every row of the data rather than just looking at data[0]

[simonw]

Here's a demo of a scatter graph against a correctly identified column:

https://datasette-vega-latest.datasette.io/?url=https%3A%2F%2Fsan-francisco.datasettes.com%2Fsf-trees-ebc2ad9%2FStreet_Tree_List.json%3F_labels%3Don#g.mark=circle&g.x_column=TreeID&g.x_type=ordinal&g.y_column=qCaretaker.label&g.y_type=ordinal

And here's the same demo against the incorrectly identified qCareAssistant:

https://datasette-vega-latest.datasette.io/?url=https%3A%2F%2Fsan-francisco.datasettes.com%2Fsf-trees-ebc2ad9%2FStreet_Tree_List.json%3F_labels%3Don#g.mark=circle&g.x_column=TreeID&g.x_type=ordinal&g.y_column=qCareAssistant&g.y_type=ordinal

[simonw]

https://datasette-vega-latest.datasette.io/?url=https%3A%2F%2Fsan-francisco.datasettes.com%2Fsf-trees-ebc2ad9%2FStreet_Tree_List.json%3F_labels%3Don#g.mark=circle&g.x_column=TreeID&g.x_type=ordinal&g.y_column=qCareAssistant.label&g.y_type=ordinal now works: