Missing Attribute definations

[NikhilSP]

A few of the spec texts are missing in my dxf. After debugging I found that there is no attribute in dxf.Entities.AttributeDefinitions which has the handle value as same as of those text. I have attached the part of dxf below. Text "NIC2324" is not getting displayed on screen. What could be the possible reason for missing attribute definitions or where should I look?

(The value after 1 is empty in original dxf too) 0 ATTDEF 5 EBA7 330 2898 100 AcDbEntity 8 0 6 Continuous 62 7 370 -3 100 AcDbText 10 257.94316280237 20 484.7253392768378 30 0.0 40 2.5 1

50 90.0 41 0.8 72 2 11 258.7764961357033 21 491.3920059435044 31 0.0 100 AcDbAttributeDefinition 3 ENTER SPEC TAG 1 2 NIC2324 70 0 74 1 280 0 71 1 72 0 11 258.7764961357033 21 491.3920059435044 31 0.0

[sebastiankozub]

Having similar issue... When opening DXF file in de-cuff-viewer displaying more items on the screen and having 944 attribute definitions. When I count all attribute definitions from all DxfDocument.Blocks[] I have only 108 definitions. There is 4 more in DxfDocument.Entities.AttributeDefinitions but they are also in first block. Is there any other place where attribute definitions hides?

[sebastiankozub]

I noticed that when there is few attribute definitions containing same: 3 | Prompt string and/or 2 | Tag string (cannot contain spaces) the DxfDocument contain only one of those attributes...

[sebastiankozub]

Having those 2 attribute definitions in DXF file. DxfDocument contain only one of them:

First:

ATTDEF 5 114DE 330 5308 100 AcDbEntity 8 0 6 Continuous 62 7 370 -3 100 AcDbText 10 194.3718116027041 20 201.6237524133556 30 0.0 40 2.5 1

50 90.0 41 0.8 72 2 11 195.2051449360374 21 206.2904190800223 31 0.0 100 AcDbAttributeDefinition 3 ENTER SPEC TAG 1 2 1G4 70 0 74 1 280 0 71 1 72 0 11 195.2051449360374 21 206.2904190800223 31 0.0 0 ATTDEF

Second:

ATTDEF 5 1147A 330 5308 100 AcDbEntity 8 0 6 Continuous 62 7 370 -3 100 AcDbText 10 423.9105809632231 20 150.4010964133757 30 0.0 40 2.5 1

50 90.0 41 0.8 72 2 11 424.7439142965565 21 155.0677630800424 31 0.0 100 AcDbAttributeDefinition 3 ENTER SPEC TAG 1 2 1G4 70 0 74 1 280 0 71 1 72 0 11 424.7439142965565 21 155.0677630800424 31 0.0 0 ATTDEF

Any hints for a code file or line that needs to be debugged or changed to have both definitions in the DxfDocument collections?

[haplokuon]

Attribute definitions with the same tag are not allowed and will be automatically deleted, this is on purpose. I know that the DXF allows it but I don't. The main problem with it is that the tag string is the only way to reference the attribute to the original attribute definition, therefore if multiple attribute definitions can have the same tag that link is lost. If you modify any attribute definition of the block there will be no way to propagate the changes to all inserts that references the block. You still have access to all attributes of the insert, regardless if they were created by an attribute definition with a duplicate tag or not.

Sometime, in the past, the AutoCad developers realize that it was not a good idea and it will show in red in the block attribute manager attribute definitions with the same tag. This is something you can read in the AutoCad official documentation "Identify duplicate tag names. Because duplicate tag names can lead to unpredictable results, you can set the Block Attribute Manager to highlight duplicate tags so that you can change them."

So, unless, there is a very good reason I will keep it the way it is. It is a very bad practice duplicating tags.

@Nikhilsp In general a piece of a DXF has very little use, post the whole DXF instead.

[sebastiankozub]

Thanks @haplokuon for quick and comprehensive answer that gives clues to make decisions - generally we need those entities so probably forking your solution and parametrize the constructor :)