PropertySet-class: PropertySet-class

In objectProperties: A Factory of Self-Describing Properties

PropertySet-class

Description

The PropertySet class is a collection of properties and is useful as a data model, e.g., for storing the parameters of some operation.

setPropertySet is a simple wrapper around setRefClass for creating subclasses of PropertySet. It ensures that all fields of the subclass are defined via properties.

Usage

setPropertySet(Class, fields=list(), prototype=list(), contains="PropertySet", ...,
    where=topenv(parent.frame()))

Arguments

Class	class name
fields	list of fields
prototype	list of default values, as in setClass.
contains	superclasses, one of which must extend PropertySet
...	additional arguments to setRefClass
where	the environment in which to define the class

Details

PropertySet-class: PropertySet object has following methods, where x is a PropertySet object:

x$properties()

Return the classes of the properties as a named character vector. Compare to the fields method on a reference class generator

.

as.list(x)

Returns a named list of the property values.

When any property in the set changes, the changed(name) signal is emitted, where name is the name of the property that changed.

Value

setPropertySet: the class generator object

Author(s)

Michael Lawrence, Tengfei Yin

Examples

filt.gen <- setRefClass("Filter", properties(fields = list(cutoff = "numeric",
                                                           weight = "numeric"),
                                  prototype = list(cutoff = 0, weight = 1)),
                                  contains = "PropertySet")
obj <- filt.gen$new()
obj
obj$properties()
as.list(obj)
obj$changed$connect(function(name) print(name))
obj$cutoffChanged$connect(function() print(paste("change to", obj$cutoff)))
obj$cutoff <- 0
obj$cutoff <- 2
obj$weight <- 3


## use setPropertySet, the same thing as above
filt.gen <- setPropertySet("Filter", fields = list(cutoff = "numeric",
                                         weight = "numeric"),
                           prototype = list(cutoff = 0, weight = 1))

obj <- filt.gen$new()
obj
obj$properties()
as.list(obj)
obj$changed$connect(function(name) print(name))
obj$cutoffChanged$connect(function() print(paste("change to", obj$cutoff)))
obj$cutoff <- 0
obj$cutoff <- 2
obj$weight <- 3

objectProperties documentation built on May 3, 2022, 1:08 a.m.