SD196926 - Using the Visual LISP Extension with AutoLISP

SD196926 - Using the Visual LISP

Extension with AutoLISP

Lee Ambrosius

Principal Learning Experience Designer

Where Am I and Who Should Be Here

You are in session:

• SD196926 - Using the Visual LISP Extension with AutoLISP

You should know:

• AutoCAD 2019 (or AutoCAD 2012 and later)

• Fundamentals of AutoLISP programming

You should want to:

• Automate tasks through programming

• Extend the functionality of existing AutoLISP programs

Who Am I?

My name is Lee Ambrosius:

• Principal Learning Experience Designer at Autodesk, Inc.

• Over 20+ years of AutoCAD customization and programming experience

• Customization, Developer, and CAD Administration documentation

• Author of the AutoCAD Customization Platform book series published by Wiley & Sons

My job in a nutshell:

• Document the past and present AutoCAD releases for the future

Session Rules

• Silence your mobile phone, tablet, and any other device

• If you have to leave, please do so quietly

• I will allow time to ask questions during the session unless we start getting behind

Enjoy the Journey

The path isn’t the same for everyone…

but the goal is often shared by many.

To the left and right of you is someone

with a shared interest, talk and learn from them.

Let’s Get Going

What You Will Learn Today

At the end of this session, you will know how to:

• Access objects in an open or closed drawing with the AutoCAD ActiveX/COM library

• Access and store values with Xdata, Dictionaries, and the Windows® Registry

• Monitor changes to objects in a drawing with reactors

• Manipulate the Windows environment

• Drive Microsoft® Office applications; Word, Excel, and Access

What You Need to Get Started

For the samples covered in this session, you will need:

• AutoCAD 2019 (AutoCAD 2012 or later)

• Notepad or the Visual LISP IDE

• Microsoft Office

• Windows 7 or later

Visual LISP Extension

Visual LISP Extension

Introduced back in AutoCAD 2000

Extends the AutoLISP programming language

• New geometric functions

• ActiveX/COM technologies

Loaded using the vl-load-com function

The Visual LISP IDE was introduced too… But isn’t the focus of Today.

AutoCAD ActiveX/COM Libraries

AutoCAD 2019 Type Library (acax23enu.tlb)

• Access to application, drawing windows, and objects in open drawings

• Imported with the vl-load-com function

AutoCAD/ObjectDBX Common 23.0 Type Library (axdb23enu.tlb)

• Access to files on disk without opening them in the application

• Imported with the vlax-import-type-library function

AutoCAD ActiveX/COM Libraries

Once loaded/imported, the AutoCAD ActiveX/COM libraries allow you to

• Create and modify objects in Model or Paper space

• Work with named objects; blocks, layers, and text styles

• Manipulate a subset of the AutoCAD application options

• Open and work drawings in memory

Members of a COM Object

Many AutoCAD COM related functions expect values of the vla-object data type

vla-object data type represents a COM object

vlax-dump-object function lists the methods/properties of a COM object

(vlax-dump-object obj [flag])

Example:

(vlax-dump-object (vlax-get-acad-object) T)

Members of a COM Object

; IAcadApplication: An instance of the AutoCAD application

; Property values:

; ActiveDocument = #<VLA-OBJECT IAcadDocument 0000023b4d814a78>

; Application (RO) = #<VLA-OBJECT IAcadApplication 00007ff7f2b1b0a8>

…

; Name (RO) = "AutoCAD"

; Path (RO) = "C:\\Program Files\\Autodesk\\AutoCAD 2019"

…

; Methods supported:

; Eval (1)

…

; Quit ()

; ZoomAll ()

…

Mixing “Legacy” AutoLISP and Visual LISP Functions

vla-object objects and entity names (ename) are not compatible

Must be transformed based on function usage:

• vlax-ename->vla-object – Transforms an ename into a vla-object

• vlax-vla-object->ename – Transforms a vla-object into an ename

ActiveX doesn’t know what a list is, but knows what an array is:

• vlax-make-safearray – Creates an array

• vlax-safearray-fill – Fills an array based on the values of a list

• vlax-safearray->list – Transforms an array to a list

Accessing Property Values without DXF or ActiveX

AutoCAD 2012 introduced four functions that simplified access to object properties:

• dumpallproperties – Outputs all the properties and their current value for the

specified entity

• getpropertyvalue – Returns the current value of the specified property for an entity

• ispropertyreadonly – Returns T or nil of the specified property for an entity is read-

only or not

• setpropertyvalue – Sets the specified property to a new value for an entity

Access Objects in an Open Drawing


Sample Code: Create a blue circle in the current space and drawing

• CreateCircle-Cmds – Using commands

• CreateCircle-Dxf – Using DXF code values and no commands

• CreateCircle-SetProp – No commands or DXF manipulation

• CreateCircle-VL – Using the ActiveX via the Visual LISP extension


Sample Code: Set color, linetype, and lineweight properties of objects to ByLayer

• ChangeAll2ByLayer-Cmds – Using commands

• ChangeAll2ByLayer-Dxf – Using DXF code values and no commands

• ChangeAll2ByLayer-SetProp – No commands or DXF manipulation

• ChangeAll2ByLayer-VL – Using the ActiveX via the Visual LISP extension

Open and Close External Drawings

Access Objects in an External Drawing File

AutoCAD/ObjectDBX Common 23.0 Type Library must be imported first

COM library is imported using the vlax-import-type-library function

(vlax-import-type-library :tlb-filename filename

[:methods-prefix mprefix

:properties-prefix pprefix

:constants-prefix cprefix])

vlax-create-object function is used to create an instance of a COM object

(vlax-create-object prog-id)


Example:

(vlax-import-type-library

:tlb-filename "C:\\Program Files\\Common Files

\\Autodesk Shared\\axdb23enu.tlb"

:methods-prefix "acdbm-"

:properties-prefix "acdbp-"

:constants-prefix "acdbc-"

)

(vlax-create-object "ObjectDBX.AxDbDocument.23")


Sample Code: Copy all dimension styles into the current drawing from an external

drawing

• AccessExternalDrawing

Store and Access Information Later

Store and Access Information Later

You can store values in different ways:

• Local variables hold values while a function is executing

• Global variables can hold information while a drawing remains open

• Variables can be defined on the blackboard and accessed across open drawings

• Windows Registry allows you to store and access information between different sessions

• Xdata, custom dictionaries, and xrecords can be used to store data in a drawing which

can be accessed when the drawing is opened

Visual LISP Blackboard

Blackboard allows you to store and access values across all open drawings

• vl-bb-set – Assigns a value to a variable on the blackboard

• vl-bb-ref – Returns the value of a variable on the blackboard

Variables on the blackboard don’t affect local or global variables

Sample Code: Store and retrieve values from the blackboard

• Blackboard

Windows Registry

Values in the Windows Registry persist between sessions; great for app settings

• vl-registry-write – Writes a value to a key

• vl-registry-read – Returns the value assigned to a key

• vl-registry-delete – Removes a key in the Registry

• vl-registry-descendents – Returns a list of subkeys

Note: PList files on the Mac OS mimic the Windows Registry to some extent

Windows Registry

Sample Code: Read and write values stored in the Windows Registry

• WinReg

eXtended Data (Xdata)

Custom data attached directly to a graphical object

Must be associated with a registered application

• Registration of an application is done with the regapp function

(regapp app_name)

Structured data based on DXF data type and value pairings

(-3 ("ACAD" (1000 . "DSTYLE") (1002 . "{") (1070 . 347)

(1005 . "220") (1002 . "}"))


Xdata can be managed with these Visual LISP functions

• vla-getxdata – Returns two arrays that represent DXF data type and value pairings

• vla-setxdata – Assigns the xdata to an object defined in two arrays


In comparison, Xdata can be managed with these “Legacy” AutoLISP functions

• entget – Gets the entity data associated with an object including its xdata

• assoc – Searches a list for an element and returns the associated element list

• subst – Substitutes an item in a list

• cons – Creates a dotted pair

• list – Creates a new list

• append – Combines two lists together

• entmod – Modifies an entity’s definition

• entupd – Updates the on-screen graphics for an entity


Sample Code: Assign and remove Xdata with Visual LISP functions

• SetXdata-VL

• RemoveXdata-VL

Sample Code: Retrieve and list assigned Xdata

• ListXdata

Sample Code: Assign and remove Xdata with “Legacy” AutoLISP

• SetXdata

• RemoveXdata

Dictionaries and Xrecords

Custom data that can be

• Stored in the named dictionary collection of a

drawing

• Attached to a graphical or non-graphical object

via an extension dictionary

Doesn’t require an application to be registered

Structured data based on DXF data type and

value pairings


Dictionaries and Xrecords can be managed with these Visual LISP functions

• vla-get-dictionaries – Gets the Dictionaries collection of a drawing

• vla-addxrecord – Adds an xrecord to a dictionary

• vla-setxrecorddata – Sets the data for an xrecord

• vla-getxrecorddata – Gets the data assigned to an xrecord

• vla-getextensiondictionary – Returns an object’s extension dictionary

• vla-get-hasextensiondictionary – Returns :vlax-true or :vlax-false

whether an object has an extension dictionary


Xrecords and dictionaries can be managed with these “Legacy” AutoLISP functions

• namedobjdict – Returns the named object dictionary for the drawing

• dictadd – Adds a custom dictionary or xrecord to the specified entity

• dictremove – Removes a custom dictionary

• dictnext – Returns the next entry in a dictionary

• dictrename – Renames a dictionary from the old name to a new name

• dictsearch – Searches a dictionary for an entry

• entmakex – Creates a new graphical or non-graphical object in memory

Note: Functions previously mentioned for working with Xdata are also required


Sample Code: Create and remove a custom dictionary with Visual LISP functions

• CreateDictionary-VL

• DeleteDictionary-VL

Sample Code: Retrieve and print an xrecord attached to a dictionary

• PrintXrec-VL

• PrintXrec

Sample Code: Create and remove a custom dictionary with “Legacy” AutoLISP

• CreateDictionary

• DeleteDictionary

Monitoring Activities in AutoCAD

Reactors

Reactors watch for and react to certain situations that occur

• in a drawing database

• to an object

• at the application level

Must be registered with a callback function before they can be used

Callback functions define what happens when the reactor is fired by the application

command function CAN’T be used in a reactor

Reactors

Registered using functions that start with vlr-

• VLR-Editor-Reactor - Drawing reactor (opening or closing a drawing file)

• VLR-Insert-Reactor - Block insertion reactor

• VLR-Command-Reactor - Command reactor (command starts, ends, and fails)

• VLR-Lisp-Reactor - LISP reactor

• …

Sample Code: Monitors for the use of the Qdim, Hatch, Batch, and Gradient

commands

Working with Windows


Some of the Windows COM libraries available allow you to:

• Create file shortcuts

• Access special named folders; Documents, Pictures, …

• Query and set environment variables

• Access the drive, folder, and file structures of Windows

• Identify installed printers


Two of the most useful Windows COM libraries are:

• Windows Host Scripting Object (wshom.ocx)

• Microsoft Scripting Runtime libraries (scrrun.dll)

Libraries are located in c:\windows\system32


Sample Code: Create a shortcut on the Desktop

• CreateDesktopShortcut

Sample Code: Get, set, and expand environment variables

• GetEnvStr

• SetEnvStr

• ExpEnvStr

Sample Code: List available drives

• ListDrives

Working with Microsoft Office


Microsoft provides a number of COM libraries to interact with Microsoft Office:

• Print a Microsoft Word document to the default printer

• Create a new Microsoft Word document based on information in an AutoCAD drawing

• Push and pull information from an Microsoft Excel spreadsheet to modify content in a

drawing

• Query and modify information in a Microsoft Access (MDB) database


Most common COM libraries associated with the applications in Microsoft Office:

• Microsoft Word 16.0 Object Library (msword.olb)

• Microsoft Excel 16.0 Object Library(excel.exe)

• Microsoft ActiveX Data Objects 6.1 Library (msado15.dll)

Libraries are located in the

• Microsoft Office installation folder

• Program Files\Common Files folder


Sample Code: Print and create Microsoft Word documents

• PrintMSWordDoc

• CreateMSWordDoc

Sample Code: Extract and update object property values with Microsoft Excel

• ExtractDrawingToExcel

• UpdateDrawingFromExcel

Sample Code: List available drives

• AccessDatabaseADO

Final Thoughts and Questions

Final Thoughts and Questions

Customization and programming can:

• Enhance productivity

• Improve or introduce new workflows

Customizing has many similarities to Wonderland in

Lewis Caroll’s Alice’s Adventures. Both

• are virtually endless

• hold many mysteries waiting to be discovered

Closing Remarks

Thanks for choosing this session.

Don’t forget to complete this session’s survey.

If you have any further questions, contact me via:

email: [email protected]

twitter: @leeambrosius

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