Separate fields and their format in options

[light-and-salt]

Currently, the complete structure of options look like this:

var options = {
  showFields: [{ // specify data fields to be shown in the tooltip
    field: ..., // field name in the dataset
    fieldTitle: ..., // (optional) field title the tooltip should display
    type: 'date' | 'number' | 'string',
    format: timeUnit | string specifier
  }],
  offset: { // x and y offset (in pixels) of the tooltip
    x: 10,
    y: 10
  },
  colorTheme: 'light' | 'dark' // specify a color theme the tooltip should use
}

For both Vega-Lite and Vega tooltips, if you want to specify the format of a field you have to put an object like {field:..., format: ...} into options.showFields[], and if you put in an object for one field you have to put in objects for all the other fields that you want to display in the tooltip (because the tooltip plugin right now assumes you only want to display the fields in the showFields array).

It's better to separate fields and their formats. If a user wants to specify a format, she specifies the format -- it doesn't affect the "which fields get displayed" decision.

var options = {
  showFields: ['field1', 'field2', 'field3'],
  fieldsConfig: {
    field1: {
      fieldTitle: ..., // (optional) field title the tooltip should display
      type: 'time' | 'number' | 'string',
      format: timeUnit | string specifier
    }
  },
  offset: { // x and y offset (in pixels) of the tooltip
    x: 10,
    y: 10
  },
  colorTheme: 'light' | 'dark' // specify a color theme the tooltip should use
}

[domoritz]

@kanitw I suggested this because otherwise it's hard to distinguish between e.g. configuring the formatter and saying that a particular field should be displayed.

[kanitw]

I don't know what you two mean "name the field". (Is this VL or VG?)

[domoritz]

This mainly applies to vl but imaging in vg if you want to specify the format of one field but still display all fields in the tooltip.

[light-and-salt]

Sorry for the confusion. I just updated my original comment. By "name the field" I mean putting a field in options.showField[]

[light-and-salt]

Close as we discussed in #34: we will combine fields and fieldConfigs with an showAllFields: boolean option