gUpdateDataMessage-class {iSPlot} | R Documentation

## Class "gUpdateDataMessage": A class to represent an update data message

### Description

`gUpdateDataMessage` is a class to represent an update data message. When either the controller or the views (i.e. the control window or the views) want to update the data, a `gUpdateDataMessage` object is created. gUpdateDataMessage is inherited from the class, gUpdateMessage, which inherits from the virtual class, gMessage. Whenever a gUpdateDataMessage is created (initialized), the next step is to call the handleMessage method to act upon that message and update the data.

### Objects from the Class

Objects can be created by calls of the form `new("gUpdateDataMessage", from, where, ...)`. When creating a gUpdateDataMessage object, the `from` parameter is the object that is telling the data to be updated. Currently, the `from` parameter will be an object of class sPlotView or spreadView. The where parameter is what point of the data should be updated (this is returned by the function, identifyPoint). The initialize method for gUpdateDataMessage will call the method, `viewUpdateData`, to ensure that the message is properly initialized when it is created.

### Slots

`to`:
  which data set is to be updated; a character string
`type`:
  the type of update to be performed; one of the following strings: "add", "reset", "modify", or "delete"
`mData`:
  the data needed to perform the update; will be a list that may contain the data name, the row name, the column name and/or the new data

### Extends

Class `"gUpdateMessage"`, directly. Class `"gMessage"`, by class `"gUpdateMessage"`.

### Methods

handleMessage
  Updates the named data and then if views are present, calls the function, updateViews, to update any views that depend on the changed data
initialize
  Creates a gUpdateDataMessage object
to
  Returns the `to` slot
to<-
  Sets the `to` slot

### Author(s)

Elizabeth Whalen

### See Also

`updateViews`, `gMessage-class`, `gUpdateMessage-class`, `gUpdateViewMessage-class`

### Examples

      if (interactive())
      {
        createControlWindow()
        # should load data through Open Data or Open File under the File menu
        data(USArrests)
        loadDFData(USArrests,"USArrests")
        # plotting the data should occur through Plot Data under the
        # Display menu
        createView(type = "plotView", dataName = "USArrests",
                   plotType = "sPlotView", dfRows = 1:nrow(USArrests),
                   dfColumns = 1:2)
        # should set highlight mode through Highlight under the ViewMode menu
        setHighlightMode()
        # should create a gUpdateDataMessage object by clicking on the plot
        curpt<-identifyPoint(curplot=getActivePlot(),xyloc=list(x=2.7,y=72))
        dMessage<-new("gUpdateDataMessage",from=getActivePlot(),
                      where=curpt)
        handleMessage(dMessage)
      }

[Package iSPlot version 1.0.7 Index]