skills/tableau-workbook-authoring/resources/examples/parameter.json

{
  "_description": "Parameter definition and usage in a calculated field. Parameters live in a special datasource named 'Parameters'. Reference with [Parameters].[Parameter N].",
  "_feature": "parameter,calculated-field",
  "parameter_datasource": {
    "_description": "The Parameters datasource is a special built-in datasource. Add parameter columns to it.",
    "type": "datasource",
    "attrs": {
      "name": "Parameters",
      "inline": "true"
    },
    "children": [
      {
        "type": "column",
        "attrs": {
          "caption": "Top N",
          "datatype": "integer",
          "name": "[Parameter 1]",
          "param-domain-type": "range",
          "role": "measure",
          "type": "quantitative",
          "value": "10"
        },
        "children": [
          {
            "type": "calculation",
            "attrs": {
              "class": "tableau",
              "formula": "10"
            }
          },
          {
            "type": "range",
            "attrs": {
              "granularity": "1",
              "max": "100",
              "min": "1"
            }
          }
        ]
      }
    ]
  },
  "calc_using_parameter": {
    "_description": "A calculated field in a regular datasource that references the parameter",
    "type": "column",
    "attrs": {
      "caption": "Is Top N",
      "datatype": "boolean",
      "name": "[Calculation_TopN_Check]",
      "role": "dimension",
      "type": "nominal"
    },
    "children": [
      {
        "type": "calculation",
        "attrs": {
          "class": "tableau",
          "formula": "RANK(SUM([Sales])) <= [Parameters].[Parameter 1]"
        }
      }
    ]
  },
  "parameter_types": {
    "integer_range": { "datatype": "integer", "param-domain-type": "range", "min": "1", "max": "100" },
    "float_range": { "datatype": "real", "param-domain-type": "range", "min": "0.0", "max": "1.0" },
    "string_list": { "datatype": "string", "param-domain-type": "list" },
    "boolean": { "datatype": "boolean", "param-domain-type": "all" },
    "all_values": { "datatype": "integer", "param-domain-type": "all", "note": "No min/max/list constraint" }
  },
  "notes": {
    "datasource_name": "Parameters datasource name is ALWAYS exactly 'Parameters' (capital P)",
    "column_name_format": "[Parameter 1], [Parameter 2], etc. — Tableau auto-numbers them",
    "reference_in_calc": "[Parameters].[Parameter N] — always reference by datasource name + column name",
    "value_attr": "Current parameter value is stored in the 'value' attribute of the column node",
    "param_domain_type_values": ["all", "list", "range"],
    "formula_attr": "The calculation formula just echoes the default value: formula='10' for default=10"
  }
}