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=?UTF-8?Q?Re=3A_=5Bxml-dev=5D_Convert_one_XML_format_to_another_and?==?U

• From: Thomas Passin <list1@tompassin.net>
• To: xml-dev@lists.xml.org
• Date: Sat, 29 Jun 2024 14:07:07 -0400

On 6/29/2024 11:59 AM, Roger L Costello wrote:

Hi Folks,

I am writing a program that converts an old XML format to a new XML format. In addition to doing the conversion, I also need to */verify the conversion/*. I have two questions:

1.What does it mean to “verify the conversion”? Does XSD validation constitute verifying the conversion? My sense is no. My sense is that each */action/* taken during the conversion must be verified. Do you agree with that?

2.As I do the conversion, I simultaneously output (to a separate file) metadata for each conversion action. What metadata should I generate to enable the conversion to be verified?

Allow me to explain …

My program converts this old format:

<Airport_Name>Boston Logan Airport</Airport_Name>

to this new format:

<name>Boston Logan Airport</name>

Old format:

<Airport_Elevation>19</Airport_Elevation>

New format:

<elevation>19</elevation>

Old:

<Airport_Reference_Point_Latitude>N42214660</Airport_Reference_Point_Latitude>

New:

<latitude>
<deg>42</deg>
<min>21</min>
<sec>46</sec>
<hSec>60</hSec>
<northSouth>North</northSouth>
</latitude>

Not only am I responsible for converting the old format to the new format, I am also required to */verify the conversion/*.

Truthfully, I am unclear what it means to “verify the conversion.” There is an XML Schema for the new format. I could (and certainly will) validate the file that is generated by my program. Is XSD-validation verifying the conversion? My sense is no. I think that “verify the conversion” means verify each */action/* taken during the conversion. Do you agree with that?

“… verify each */action/* taken during the conversion.” Here’s my plan of attack: My program will output -- to another, different file -- metadata that describes the actions that were taken during the conversion.

Once again, I am unclear. What metadata is needed to verify an action? The metadata will be machine processed, so I am thinking that the metadata had better contain predicates (expressions that evaluate to true or false) since they can be easily evaluated by a machine.

Here’s the metadata that I am currently generating when I convert Airport_Name to name:

<mapping>
<description>Map Airport_Name to name</description>
<legacy-elmt-name>Airport_Name</legacy-elmt-name>
<legacy-elmt-value>GENERAL EDWARD LAWRENCE LOGAN </legacy-elmt-value>
<new-elmt-name>name</new-elmt-name>
<new-elmt-value>GENERAL EDWARD LAWRENCE LOGAN</new-elmt-value>
<predicate>Airport_Name = name</predicate>
</mapping>

The value of <predicate> is a predicate expression (does the value of Airport_Name equal the value of name).

Here’s the metadata that I generate when I convert Airport_Elevation to elevation:

<mapping>
<description>Map Airport_Elevation to elevation</description>
<legacy-elmt-name>Airport_Elevation</legacy-elmt-name>
<legacy-elmt-value>19</legacy-elmt-value>
<new-elmt-name>elevation</new-elmt-name>
<new-elmt-value>19</new-elmt-value>
<predicate>Airport_Elevation = elevation</predicate>
</mapping>

Here’s the metadata that I generate when I convert Airport_Reference_Point_Latitude to latitude:

<mapping>
<description>Map Airport_Reference_Point_Latitude to latitude</description>
<legacy-elmt-name>Airport_Reference_Point_Latitude</legacy-elmt-name>
<legacy-elmt-value>N42214660</legacy-elmt-value>
<new-elmt-name>latitude</new-elmt-name>
<new-elmt-value>
<latitude>
<deg>42</deg>
<min>21</min>
<sec>46</sec>
<hSec>60</hSec>
<northSouth>North</northSouth>
</latitude>
</new-elmt-value>
<predicate>

substring(Airport_Reference_Point_Latitude,2,2) = latitude/deg and
       substring(Airport_Reference_Point_Latitude,4,2) = latitude/min and
       substring(Airport_Reference_Point_Latitude,6,2) = latitude/sec and
       substring(Airport_Reference_Point_Latitude,8,2) = latitude/hSec and
       (
         (substring(Airport_Reference_Point_Latitude,1,1) = 'N' and latitude/NorthSouth = 'North') or
        (substring(Airport_Reference_Point_Latitude,1,1) = 'S' and latitude/NorthSouth = 'South') or
        (empty(latitude/NorthSouth))
      )
    </predicate>
</mapping>

Is that the metadata I should generate to enable the conversion to be verified?

/Roger

• References:
  • Convert one XML format to another and verify the conversion … how to “verify the conversion”?
    • From: Roger L Costello <costello@mitre.org>