vl.topojsonFormat(…values)
Specify parsing of topojson
format data.
topojsonFormat
Method OverviewtopojsonFormat
API Reference# topojsonFormat.feature(value)
The name of the TopoJSON object set to convert to a GeoJSON feature collection. For example, in a map of the world, there may be an object set named "countries"
. Using the feature property, we can extract this set and generate a GeoJSON feature object for each country.
# topojsonFormat.mesh(value)
The name of the TopoJSON object set to convert to mesh. Similar to the feature
option, mesh
extracts a named TopoJSON object set. Unlike the feature
option, the corresponding geo data is returned as a single, unified mesh instance, not as individual GeoJSON features. Extracting a mesh is useful for more efficiently drawing borders or other geographic elements that you do not need to associate with specific regions such as individual countries, states or counties.
# topojsonFormat.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
# topojsonFormat.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.