Programming Mechworks PDM > DBWCommandShell > Programmer's Guide

available from build: 20040906

Description

It is possible to launch .VBS scripts from MechworksPDM in an asynchronous way.
In order to have a script be launched asynchronously, the special keyword:

.ASYNCH

must be declared as comment in the head of the script ( see the example below ).

Remarks

Asynchronous scripts are designed for launching tasks that do not modify the database and/or the models; typically they can be used for scripts making reports or queries that can take a long time to be executed. Due to the asynchronous way of starting the scripts, any call to functions related to the current selection in the browser may give unexpected results. Only functions addressing the document through the UNIQUE_ID must be used in an asynchronous script. Please consider the following case:

1.select document with unique_id=100 in the browser

2.start an asynchronous script

3.while the script is starting change the current selection to a document with unique_id=101

4.the script started, and calls the DBWShell("CurrentDocument"): the current document is now 101, and not 100 as when the script was asked to start

To help in this situations, a set of constants is available for asynchronous scripts:

const DBWorksCurrentDocumentUniqueId

const DBWorksCurrentDocumentType
const DBWorksCurrentDocumentId
const DBWorksCurrentDocumentIdNoSpace
const DBWorksCurrentSelection

They contains the same strings as the parameters returned from the commands

DBWShell("CurrentDocument")

and

DBWShell("GetSelection")

and can help in getting the correct current selection in the browser.

For example, a script code written as:

call DBWShell( "CurrentDocument" )

docUID = DBWResult("@DOCUMENT_UNIQUE_ID")

should be rewritten as

docUID = DBWorksCurrentDocumentUniqueId

and

DBWShell("GetSelection")

selection = DBWResult("@SELECTION")

should be rewritten as

selection = DBWorksCurrentSelection

Example

Please note you should not invoke commands belonging to MechworksPDM environment, otherwise the asynchonicity wont' be maintained.

In the below case it's used a MsgBox instead of a DBWMsgBox

'.ASYNCH

Sub Main()
DBWInit(TRUE)
MsgBox "I am an asynchronous script!"
End Sub