Using the Windows Clipboard in FoxPro

The Windows Clipboard in easily accessed in FoxPro and Visual FoxPro (VFP). There are currently two commands that directly relate to it. These are _CLIPTEXT to copy and paste text and DataToClip() to copy values from a table. These are not highly sophisticated commands, but they are quick and straightforward and are often the simplest way to transfer data between applications.

Let us explore these two VFP commands further and provide some examples:

_CLIPTEXT System Variable

The _CLIPTEXT System Variable contains the content of the Windows Clipboard and can be engaged to write text to and read text from the Clipboard. This feature has been available since the earliest versions of FoxPro for Windows. The syntax is very simple:

_CLIPTEXT = cExpression && writes cExpression to the Clipboard

cExpression = _CLIPTEXT && stores the Clipboard content to cExpression

One of the most common uses of _CLIPTEXT is during program development. Long SQL statements, commands and other strings generated by programs at runtime are often difficult to debug using VFP’s standard tools. In the following code sample an SQL statement is copied to the Windows Clipboard so the developer can paste it into a wordprocessor or other application for additional analysis:

cSQL = cFields + cSource +cFilter + cOrder + cOutput

_CLIPTEXT = cSQL

SET STEP ON && opens the Trace window and suspends the program

DataToClip Method

DataToClip() copies a set of records to the Windows Clipboard. It is a method of the Application Object or the _VFP System Variable. The field names appear as the first line of the text copied to the Clipboard followed by a separate line for each record. This method has been available since VFP 5 and is only slightly more complicated:

Syntax

ApplicationObject.DataToClip([nWorkArea | cTableAlias] [, nRecords] [, nClipFormat])

Arguments

nWorkArea

Specifies the work area number of the table for which records are copied to the Clipboard. If you omit cTableAlias and nWorkArea, records are copied to the Clipboard for the table open in the current work area.

cTableAlias

Specifies the alias of the table for which the records are copied to the Clipboard.

nRecords

Specifies the number of records copied to the Clipboard. If nRecords is greater than the number of remaining records in the table, all the remaining records are copied to the Clipboard. If nRecords and nClipFormat are omitted, the current record and all remaining records are copied to the Clipboard.

nClipFormat

Specifies how fields are delimited. The settings for nClipFormat are:

nClipFormat	Description
1	(Default) Fields delimited with spaces
3	Fields delimited with tabs

If nClipFormat is omitted, fields are delimited with spaces.

This following copies the current work area from the current record to the end in tab-delimited format:

_VFP.DataToClip(,,3)

This following copies the current work area from the current record to the end in space-delimited format:

_VFP.DataToClip()

There are some important limitations with the DataToClip Method. Memo field content and General fields are not copied, there is no way to apply a filter or select which fields will be copied, and bugs have been found in the method’s implementation in VFP 5 and VFP 6. Also note executing DataToClip() does not move the record pointer.