How do I control the prompt order for attributes?

When building the block definition, the selection order is the key.  If you simply window off the geometry there is a good possibility the prompt order will not be as desired.  When selecting objects for a block definition, first individually pick the attribute definitions individually in the order you want to be prompted, then select the rest of the geometry.

Importing Block Definitions

If you want to bring in only the definition of a block (such as a symbol on disk), you can use this little known trick.  After issuing the insert command and selecting the file, press the ESC key at the first (insertion point) prompt.  You will have the definition in the current drawing for latter use.

Add Descriptions to Blocks

Later versions of AutoCAD have the ability to add descriptions to the block definitions in the drawing.

• Issue the BLOCK command.

• Select the block from the list at top.

• Click in the lower 'Description' section and enter the description.

• Choose OK to redefine the block with the new description.

Building a block with fields (2006+)

This procedure will explain how to create a coordinate label block that updates as you move or copy it.

• Issue the BEDIT (block edit) command.

• Enter the desired name, like COORDBLOCK and chose OK.

• Draw the desired point identifying geometry, such as a circle at 0,0 with a radius of 0.25.

• Issue the ATTDEF command.

• Turn on the Preset toggle in the upper left, this makes for faster inserts as AutoCAD won't prompt for the attribute values (which is automatic anyway).

• Enter NORTHING for the tag and prompt fields.

• To the right of the Value field, click the 'Insert Field' button.

• In the Field Names list on the left, click 'BlockPlaceholder', this is a special area only available during block building.

• In the middle column, choose the 'Position' property.

• In the right column, format your output as desired. In this example turn off the X & Z fields and 'Current Units' is the recommended value. While you can lock the precision to a fixed number of places, it's not easy to modify a field based attribute later.

• Choose OK after completing the field formatting.

• Change 'Text Options' as desired. For this example we are only changing the height to 1.0.

• Most likely you will want to turn off the 'Lock Position' toggle so you can move the attribute after the insert.

• Choose OK to complete the first attribute. When prompted for the insertion point, pick a location or enter coordinates such as 1.0,1.2 for this example.

• Repeat at step 5 for the EASTING & ELEVATION field attributes, the only other difference being that the 'Align below previous' toggle should be turned on to make positioning easier.

• Issue the BCLOSE command or choose the 'Close Block Editor' button at the top.

• Choose Yes to save the changes.

At this point the COORDBLOCK is defined and ready to insert. As you insert them into the drawing the coordinates are filled in automatically. After moving an insert issue the REGEN command to update the values.  To make the block available for inserting into other drawings, it will need to be WBLOCKED to a separate DWG file.

• Issue the WBLOCK command.

• Choose the Block button and select COORDBLOCK in the list.

• Click the [...] in lower right to specify a filename.

• Changing the Insert Units to 'Unitless' is recommended.

Adding Attributes to Blocks

To add an attribute to a block that's already defined (and used) in the drawing, simply issue the BEDIT command, select the block defined and use the ATTDEF command. It's likely you will want to turn on the "Align below previous attribute definition" toggle. Then close the Block Editor and Save Changes.

The most important consideration now is that existing inserts don't have a placeholder for your new attribute! AutoCAD's built in ATTSYNC command can correct this. Issue the command, press enter to <Select> and pick any insert of your block, press enter to confirm. All the instances of your insert now display the newly added attribute with the default value. You can now simply double-click an insert to change the value in the enhanced attribute editor.

Block Base

When designing blocks, it's always best to create the geometry centered around the origin of 0,0. Sometimes users can create a block from geometry in model space and it ends up difficult to use when inserting the block.

To correct this, issue the BEDIT command, select the misbehaving block, then use the move command to move the block elements to 0,0. You may need to use a specific base point (such as the midpoint of a feature) to 0,0.

Block Geometry Properties

The component geometry used to create blocks should be created with a layer of 0, and other properties (especially color) set to a BYBLOCK setting. That way it will take on the properties of the layer it's inserted onto, or the specific properties you specify in the properties dialog.

Failure to do this can mean confusion. For example if you create your block geometry on layer BLOCKGEOM, then insert them on a layer like INSERTS, you will find that layer INSERTS cannot be purged, even though there are no visible objects (when the layer BLOCKGEOM is frozen). In this case the invisible insertion point prevents the layer purging.

Cloning Blocks

You can use AutoCAD's Block Editor to create copies of a block. Simply issue the BEDIT command, choose the source block, then use the Block Editors 'Save Block As' icon and designate the new name.