Hi Folks,
One of the things that I have learned from this discussion is the importance of a good specification. It is difficult
to convert one XML element to another XML element if you have a fuzzy understanding of the two elements.
So, I have nailed down the specifications for <Airport_Name> and <name> ….
Initially I thought the specification for <Airport_Name> was simple: a 30-character fixed length string, composed
of ASCII characters. Here is the XSD I created for that specification:
<xs:element name="Airport_Name">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:length value="30"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
Then you started asking probing questions: Is Airport_Name required? Can there be leading spaces? Are trailing
spaces allowed? Are multiple internal spaces allowed? Are duplicates allowed, i.e., can there be multiple airports with the same name? You said that only ASCII characters are permitted, but your XSD doesn’t reflect that. Can <Airport_Name> be blank, i.e.,
30 spaces?
The document/specification I have for Airport_Name doesn’t answer any of those questions, so I examined the data
file that I have to get some answers. Here’s what I found:
Is <Airport_Name> required? Yes
Can there be leading spaces in an airport name? No
Can there be trailing spaces? Yes
Are multiple internal spaces allowed? Yes
Are duplicates allowed? Yes
What characters are permitted in an airport name? A-Z, forward slash, left paren, right paren, comma, dash, digits,
apostrophe, ampersand, quote, space
Can <Airport_Name> be all blanks? No
Based on those answers, I updated my XSD:
<!--
The Airport_Name element is required.
Duplicate airport names are allowed. For example, the
Lowell Field Airport in Anchor Point, Alaska has this
Airport_Name:
<Airport_Name>LOWELL FLD </Airport_Name>
The Lowell Field Airport in Americus, Georgia has the same
Airport_Name:
<Airport_Name>LOWELL FLD </Airport_Name>
The value of Airport_Name is a 30-character,
fixed length string.
The value must not be all space (x20) characters.
The value must not contain leading spaces.
The value may contain zero or more trailing spaces.
Whitespace is not normalized, i.e., it's acceptable for an
airport name to contain 2 or more consecutive spaces.
The name of the airport must be in UPPERCASE letters, A-Z.
The set of characters permitted: A-Z, forward slash, left
paren, right paren, comma, dash, digits, apostrophe,
ampersand, quote, space
Here are airport names that illustrate the set of characters
that are permitted:
<Airport_Name>VANCOUVER/BOUNDARY BAY </Airport_Name>
<Airport_Name>ROBERT/BOB/CURTIS MEML </Airport_Name>
<Airport_Name>SAN JUAN /UGANIK/ </Airport_Name>
<Airport_Name>COSTELLO ISLAND, INC </Airport_Name>
<Airport_Name>COLUMBUS AFB AUX FLD, (GUNSHY)</Airport_Name>
<Airport_Name>DUKE FLD,(EGLIN AF AUX NR 3) </Airport_Name>
<Airport_Name>KANEOHE BAY MCAS (MARION E CAR</Airport_Name>
<Airport_Name>WRIGHT AAF (FORT STEWART)/MIDC</Airport_Name>
<Airport_Name>HOMER-BELUGA LAKE </Airport_Name>
<Airport_Name>SCHERTZ AERIAL SERVICE - HUDSO</Airport_Name>
<Airport_Name>18 MEADOWS AERODROME </Airport_Name>
<Airport_Name>SOUTH 80 FLD </Airport_Name>
<Airport_Name>B & B BOYS RANCH </Airport_Name>
-->
<xs:element name="Airport_Name">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:length value="30"/>
<xs:pattern value="[A-Z/\(\),\-0-9'&"][A-Z/\(\),\-0-9'&" ]+"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
Recall that I need to convert <Airport_Name> to <name>. Initially my specification of <name> was simple: The value
of <name> is a string up to 50 characters, with no trailing spaces. Here is my XSD for the <name> element:
<xs:element name="name">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:maxLength value="50"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
I asked the same questions for the <name> element:
Is <name> required?
No
Can there be leading spaces? No
Can there be trailing spaces?
No
Are multiple internal spaces allowed? Yes
Are duplicates allowed: Yes
What characters are permitted in an airport name? Use the same set of characters that <Airport_Name> uses
Can <name> be all blanks? No
The
yellow means it is different from <Airport_Name>.
Here’s my updated XSD:
<!--
The name element is optional.
Duplicate airport names are allowed. For example, the
Lowell Field Airport in Anchor Point, Alaska has this name:
<name>LOWELL FLD</name>
The Lowell Field Airport in Americus, Georgia has the same name:
<name>LOWELL FLD</name>
The value of name is a string with at most 50 characters.
The value must not be all space (x20) characters.
The value must not contain leading spaces.
The value must not contain trailing spaces.
Whitespace is not normalized, i.e., it's acceptable for an
airport name to contain 2 or more consecutive spaces.
The name of the airport must be in UPPERCASE letters, A-Z.
The set of characters permitted: A-Z, forward slash, left
paren, right paren, comma, dash, digits, apostrophe,
ampersand, quote, space
Here are airport names that illustrate the set of characters
that are permitted:
<name>VANCOUVER/BOUNDARY BAY</name>
<name>ROBERT/BOB/CURTIS MEML</name>
<name>SAN JUAN /UGANIK/</name>
<name>COSTELLO ISLAND, INC</name>
<name>COLUMBUS AFB AUX FLD, (GUNSHY)</name>
<name>DUKE FLD,(EGLIN AF AUX NR 3)</name>
<name>KANEOHE BAY MCAS (MARION E CAR</name>
<name>WRIGHT AAF (FORT STEWART)/MIDC</name>
<name>HOMER-BELUGA LAKE</name>
<name>SCHERTZ AERIAL SERVICE - HUDSO</name>
<name>18 MEADOWS AERODROME</name>
<name>SOUTH 80 FLD</name>
<name>B & B BOYS RANCH</name>
-->
<xs:element name="name">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:maxLength value="50"/>
<xs:pattern value="[A-Z/\(\),\-0-9'&"][A-Z/\(\),\-0-9'&" ]*[A-Z/\(\),\-0-9'&"]"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
Have I missed anything? Are there additional questions that need answering? Are my specifications complete?
/Roger
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