vl.param(name)
Define or reference a variable parameter.
param Method Overviewparam API Reference# param.bind(bind)
Input element bindings for this parameter.
See: bind documentation.
The behavior of this method depends on the argument type:
EventTarget, sets the bind.element property.bind property.# param.expr(value)
An expression for the value of the parameter. This expression may include other parameters, in which case the parameter will automatically update in response to upstream parameter changes.
# param.name(value)
A unique name for the variable parameter. Parameter names should be valid JavaScript identifiers: they should contain only alphanumeric characters (or “$”, or “_”) and may not start with a digit. Reserved keywords that may not be used as parameter names are “datum”, “event”, “item”, and “parent”.
# param.value(value)
The initial value of the parameter.
Default value: undefined