[LandXML] Re: brkType required attribute

  • From: "Nathan Crews" <nathan.crews@xxxxxxxxxxxx>
  • To: "Widhalm, Eric - Fort Collins, CO" <Eric.Widhalm@xxxxxxxxxxxx>, <gpetrik@xxxxxxxxxxxxx>, <landxml@xxxxxxxxxxxxx>
  • Date: Wed, 2 Nov 2005 13:42:58 -0500

The problem is that the 1.0 specification is broken, making the <Breakline 
brkType="???"> ambiguous, but required for validation. I am never in favor of 
changing a published spec, but this is a clear defect that could be fixed 
without negative side effects. 
 
This depends on if software vendors are using this data element. I searched all 
submitted sample LandXML files for registered software and found no instances 
of <Breakline> elements.
 
If the concensous is that this would be a detriment to existing software and 
data files, then I would agree to change the 1.1 spec and leave 1.0 as-is.
 
Any other software vendors out there with an opinion on this?
 
Regards,
 
Nathan
 

        -----Original Message----- 
        From: Widhalm, Eric - Fort Collins, CO 
[mailto:Eric.Widhalm@xxxxxxxxxxxx] 
        Sent: Wed 11/2/2005 11:29 AM 
        To: Nathan Crews; gpetrik@xxxxxxxxxxxxx; landxml@xxxxxxxxxxxxx 
        Cc: 
        Subject: RE: [LandXML] Re: brkType required attribute
        
        
        Could I suggest that the change go to  1.1 and 1.0.1?  Lotsa code has 
been written based on the 1.0 API, and would have to be revisited/addressed 
just to get the old datasets to validate if you change 1.0 ...
        -Eric

  _____  

        From: landxml-bounce@xxxxxxxxxxxxx 
[mailto:landxml-bounce@xxxxxxxxxxxxx] On Behalf Of Nathan Crews
        Sent: Wednesday, November 02, 2005 11:09 AM
        To: gpetrik@xxxxxxxxxxxxx; landxml@xxxxxxxxxxxxx
        Subject: [LandXML] Re: brkType required attribute
        
        
        This is clearly an oversight in the LandXML specification. The 
intention was to provide an enumerated list of breaklines types, which indicate 
how it should be applied to surface modeling.
         
        I think we should fix this asap in both LandXML 1.0 and 1.1 schema 
specifications.
         
        We can add a new enumeration for "Wall, Proximity and nondestructive" 
and any others that would be useful. We could also add "curved". Please let me 
know if additional types are required.
         
        Proposal:

        Add the following enumeration:

         <xs:simpleType name="breakLineType">
          <xs:restriction base="xs:string">
           <xs:enumeration value="wall"/>
           <xs:enumeration value="proximity"/>
           <xs:enumeration value="nondestructive"/>
          </xs:restriction>
         </xs:simpleType>
        
        Then use it in:
         
         <xs:element name="Breakline">
          <xs:annotation>
           <xs:documentation>The breakline is defined by a 2D north/east or 3D 
north/east/elev list of points that define the geometry.</xs:documentation>
           <xs:documentation>is identified by the "name" 
attribute.</xs:documentation>
          </xs:annotation>
          <xs:complexType>
           <xs:sequence>
            <xs:choice>
             <xs:element ref="PntList2D"/>
             <xs:element ref="PntList3D"/>
             <!-- Here PntList2D represents 2D planametric coordinate pairs 
expressed as space delimited Northing Easting pairs. -->
            </xs:choice>
            <xs:element ref="Feature" minOccurs="0" maxOccurs="unbounded"/>
           </xs:sequence>
           <xs:attribute name="brkType" type="brkLineType" use="required"/>
           <xs:attribute name="desc" type="xs:string"/>
           <xs:attribute name="name" type="xs:string"/>
           <xs:attribute name="state" type="stateType"/>
          </xs:complexType>
         </xs:element>
        
        Regards,
         
        Nathan Crews
        www.landxml.org
         

                -----Original Message----- 
                From: landxml-bounce@xxxxxxxxxxxxx on behalf of Gergely Petrik 
                Sent: Wed 11/2/2005 9:01 AM 
                To: landxml@xxxxxxxxxxxxx 
                Cc: 
                Subject: [LandXML] Re: brkType required attribute
                
                

                It must be OK if I write out these attributes as strings (just 
as you typed them below), right? The schema says nothing about that, that's why 
I asked it here. Thanks, you helped a lot.
                
                --
                G
                
                > I can think of at least three types. Wall, Proximity and 
nondestructive
                >
                > -----Original Message-----
                > From: landxml-bounce@xxxxxxxxxxxxx
                > [mailto:landxml-bounce@xxxxxxxxxxxxx]On Behalf Of Gergely 
Petrik
                > Sent: Friday, October 28, 2005 4:45 AM
                > To: landxml@xxxxxxxxxxxxx
                > Subject: [LandXML] brkType required attribute
                >
                >
                > Dear LandXML list members,
                >
                > I found that the Breakline element of the LandXML schema has 
a required
                > attribute, namely brkType, which seems to be undefined 
(defined neither
                > textually nor with a type). Could anyone help with a 
definition or I should
                > simply neglect it?
                >
                > Thanks,
                > --
                > Greg
                
                
                
                

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