Chapter 19 Referencing Other Drawings 549

Figure 19-12: The clipped xref.

Managing Xrefs

If you have many xrefs in a drawing, you need a way to keep track of them and their relationships to your drawing. You have several techniques for managing xrefs. The Xref Manager, DesignCenter, and xref notification feature are all tools to help you with this task.

Tip Though it may be obvious, the first principle of managing xrefs is to keep them simple. Overly complex nested configurations are hard to manage, no matter what you do.

The Xref Manager

The Xref Manager dialog box is designed to let you manage xrefs from one place. This Xref Manager has the following features, explained in Table 19-2.

	Table 19-2: External Reference Dialog Box Features
Feature	What It Does
Attach	Opens the Attach Xref dialog box and enables you to specify an xref to attach to
	your drawing, as explained earlier in this chapter.
Detach	Detaches an xref. The xref is not displayed, and the xref definition is no longer
	saved in the drawing.
Reload	Reloads the most recent version of the xref. Use this whenever the xref has
	changed during a session (because someone else on a networked system has
	edited the xref drawing) or after unloading an xref.
Unload	Unloads the xref without detaching it. The xref is not displayed, but the xref
	definition is still saved in the drawing. You can then use Reload to display the
	xref again.

Continued

550 Part III Working with Data

			Table 19-2 (continued)
	Feature	What It Does
	Bind	Changes the xref to a block. Opens the Bind Xrefs dialog box, which enables you to
		choose to either bind or insert the xref.
		Bind	When creating a block from the xref, this feature changes named layers,
			text styles, dimension styles, and so on (called symbols) from the format
			xref_name|symbol_name to drawing_name$#$symbol_name,
			where # is 0 if the same name does not exist in the current drawing or
			1 if it already exists. In this way, no symbol names are duplicated. This
			method enables you to keep track of where the symbols came from.
		Insert	When creating a block from the xref, this feature removes the
			xref_name| portion of symbol names. For example, if a layer of that
			name already exists in your drawing, objects on that layer take on the
			properties of that layer, as defined in your drawing. The same applies
			to text styles, dimension styles, and so on. This method removes the
			complexity that arises with the xref naming of these symbols.
	Open	Opens the selected xref in a new drawing window.
	Xref Found At	Specifies where the xref was actually found, which may be different from the saved
		path. You can then click Save Path to save the current path. If the location of an xref
		is changed and is not in the Support Files or Project Files search path, the status of
		the xref displays as Not Found. Use the Browse button to find and open the xref
		and click Save Path. Click OK to automatically reload the xref.
Note
	You cannot bind or detach nested xrefs without binding the parent xref.

The Xref Manager is resizable so that you can easily see all the columns.

Express Tools offer two commands that can help you work with xrefs. XLIST (choose Express Blocks List Xref/Block Properties) lists properties of xrefs and blocks such as object type, layer, object, and linetype. BLOCKTOXREF (choose Express Blocks Convert Block to Xref) replaces a block with an xref (that is, another drawing file).

Xref notification

If an xref is moved or renamed while you have it displayed in an open drawing, you need to reload it. An xref can change if someone else on your network opens and edits it while you’re using it. External Reference Notification offers instant notification if an xref changes.

When you open a drawing with an xref, the status bar displays the Manage Xrefs icon. When an xref changes, a “balloon message” or window appears to notify you, including the name of the drawing and the person who changed it, as shown in Figure 19-13. Click the icon to open the Xref Manager, where you can reload the xref. You may have to browse to find its new location.

Chapter 19 Referencing Other Drawings 551

Figure 19-13: If an xref changes, the balloon message appears on the status bar to notify you.

In AutoCAD only, you can control and turn off notification using the XREFNOTIFY system variable.

DesignCenter

As explained in earlier chapters, you can use the DesignCenter to move named objects, including xrefs, from one drawing to another. To insert an xref from another drawing, choose DesignCenter from the Standard toolbar. Navigate to the drawing and double-click it to open the list of named objects. Double-click Xrefs to see a list of xrefs in the right pane as shown in Figure 19-14.

Figure 19-14: You can use the DesignCenter to insert xrefs into your drawing.

Double-click the xref that you want to insert. The External Reference dialog box opens (refer to Figure 19-2) so that you can insert the xref.

552 Part III Working with Data

The xref log file

If you set the XREFCTL system variable to 1 (by default, it’s set to 0), a copy of all xref activity for your current drawing is saved in an ASCII text file. You can read the log to troubleshoot problems that may occur. Figure 19-15 shows part of an xref log file. The log file goes in the same folder as your drawing and uses your drawing name with the .xlg filename extension.

This file can get long. Therefore, once in a while, you should delete all or part of the file.

Figure 19-15: An xref log file.

Cross-

Reference

On the

CD-ROM

The Reference Manager is a stand-alone program that manages xrefs, images, fonts, and plot configurations — outside files that are referenced in your drawing. See Chapter 26 for full coverage of the Reference Manager.

The drawing used in the following Step-by-Step exercise on managing xrefs, ab19-05.dwg, is in the Results folder on the CD-ROM.

STEP-BY-STEP: Managing Xrefs

1.Use ab19-05.dwg from your AutoCAD Bible folder if you did the previous exercise. Otherwise, open it from the Results folder of the CD-ROM.

2.Save it as ab19-06.dwg in your AutoCAD Bible folder.

3.Do one of the following:

•If you have AutoCAD: Choose Modify Clip Xref. At the Select objects: prompt, pick the xref anywhere. Press Enter. At the Enter clipping option [ON/OFF/ Clipdepth/Delete/generate Polyline/New boundary] <New>: prompt, right-click and choose Delete to delete the clip and restore the entire view of both xrefs.