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Allegro CL version 8.2
Unrevised from 8.1 to 8.2.
8.1 version

data-writer

Arguments: grid-column

Returns (or sets with setf) a function that takes a value that has been entered interactively into a grid cell and writes the value into the application object that is being represented in the grid cell. This function is called by the default write-cell-value method, and supplying a data-writer function and a data-object function is an alernative to writing your own write-cell-value method. The data-writer may be nil if this facility is not used. The default value is nil.

The data-writer function is a property of a grid-column, and is called whenever the user enters a value into a cell of that column. The function should take two arguments, which are (1) the value that has been entered by the user and optionally converted by the grid-column's data-write-converter function, and (2) the grid-row's data-object. The function is typically simply the writer function of the data-object for the attribute represented by this grid-column.

For example, in the employee grid example, each row represents an employee, and the Department column represents the department attribute of each employee. The data-writer function of the Department column is (setf department), which is simply the writer method for the department slot of an employee instance. If the user enters "Sleeping" in a cell of the Department column, then the Department column's data-writer function, (setf employee-department), is called on the data-object (an employee) of the grid-row that the modified cell is in. The employee grid example can be found on the Examples tab of the Navigator.

NOTE: Your application does not call the data-writer function; it supplies the data-writer function which is then called automatically by the system as needed.

data-writer is a property of the grid-column and row-header-column classes.

See the grid-widget class for an overview of writing grid-widget code.


Copyright (c) 1998-2012, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 8.2. This page was not revised from the 8.1 page.
Created 2010.1.21.

ToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 8.2
Unrevised from 8.1 to 8.2.
8.1 version