vl.json(…values)
Define a data source for json
format data.
The behavior of this method depends on the argument type:
Array
, sets the values
property.Iterable
, sets the values
property.Object
, sets the values
property.String
, sets the url
property.json
Method Overviewjson
API Reference# json.name(name)
A name for this data source. Use this name to update the data via the runtime API.
# json.parse(value)
If set to null
, disable type inference based on the spec and only use type inference based on the data. Alternatively, a parsing directive object can be provided for explicit data types. Each property of the object corresponds to a field name, and the value to the desired data type (one of "number"
, "boolean"
, "date"
, or null (do not parse the field)). For example, "parse": {"modified_on": "date"}
parses the modified_on
field in each input record a Date value.
For "date"
, we parse data based using JavaScript’s Date.parse()
. For Specific date formats can be provided (e.g., {foo: "date:'%m%d%Y'"}
), using the d3-time-format syntax. UTC date format parsing is supported similarly (e.g., {foo: "utc:'%m%d%Y'"}
). See more about UTC time
# json.property(value)
The JSON property containing the desired data. This parameter can be used when the loaded JSON file may have surrounding structure or meta-data. For example "property": "values.features"
is equivalent to retrieving json.values.features
from the loaded JSON object.
# json.type(value)
Type of input data: "json"
, "csv"
, "tsv"
, "dsv"
.
Default value: The default format type is determined by the extension of the file URL. If no extension is detected, "json"
will be used by default.
# json.url(url)
A URL from which to load the data.
# json.values(values)
Provide loaded data values directly.
The behavior of this method depends on the argument type:
values
property.