The following topics are covered:
The Natural simple XML Parser enables you to parse XML documents with standard Natural programs. The parser sends an event, or runs an internal subroutine callback if the next part of the document is parsed. The inline subroutine "CALLBACK" is called with the name of the current element, text, comment within an xpath-like syntax. The parser engine is included as copy code "PARSER_X". If an error occurs during parsing, e.g. the document is not wellformed, the "PARSER_ERROR" inline subroutine is called and then the parser is canceled with "ESCAPE SUBROUTINE" (see also Parser Restrictions).
For extended error handling, it is possible to change the operand6 "Error Message Text" and operand7 "Error Number" to a value less than or equal to -9000. Then the "PARSER_ERROR" inline subroutine is called and the (sub)program is canceled with "ESCAPE SUBROUTINE". If other values are less than or equal to -8000, only the parser is canceled with "ESCAPE SUBROUTINE".
The major variables of the parser are defined at the Local Data Area "PARSER-X".
The parser copycode takes the following operands:
| Operand | Format/Length | Description | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | A | XML file to be parsed | ||||||||||||||
| 2 | A | ex-XPATH to repesent element structure | ||||||||||||||
| 3 | A1 |
Type of the XPATH content:
|
||||||||||||||
| 4 | A | Parsed Data | ||||||||||||||
| 5 | L | Is TRUE if Parsed Data is empty | ||||||||||||||
| 6 | A | Error Message Text | ||||||||||||||
| 7 | I4 | Error Number |
Return value of the XPATH data:
Program Example:
* ----------------------------------------------------------------------
* CLASS NATURAL XML TOOLKIT - UTILITIES
*
* PARSER
*
* DESCRIPTION
* Parse given XML
*
*
* AUTHOR SAG
*
* (c) Copyright Software AG. All rights reserved.
*
* ----------------------------------------------------------------------
*
DEFINE DATA LOCAL
1 XML_PARSER_INPUT (A) DYNAMIC
1 XML_PARSER_ERROR_TEXT (A253)
1 XML_PARSER_RESPONSE (I4)
LOCAL USING PARSER-X /* parser internal data - do not change
LOCAL
1 XML_PARSER_XPATH (A) DYNAMIC
1 XML_PARSER_XPATH_TYPE (A1)
1 XML_PARSER_CONTENT (A) DYNAMIC
1 XML_PARSER_CONTENT_IS_EMPTY (L)
*
1 ANFANG (T)
* OUT (A) DYNAMIC
1 OUT (A126)
*
END-DEFINE
*
FORMAT (0) LS=128 PS=40
*
DEFINE WORK FILE 12 "E:\EMPLOYEE1.XML" TYPE "UNFORMATTED"
READ WORK FILE 12 XML_PARSER_INPUT
END-WORK
CLOSE WORK FILE 12
*
*
* ------------------------------------------------- INCLUDE THE PARSER
INCLUDE PARSER_X 'XML_PARSER_INPUT' /* XML file to be parsed
'XML_PARSER_XPATH' /* XPATH to represent element...
'XML_PARSER_XPATH_TYPE' /* Type of callback
'XML_PARSER_CONTENT' /* Content of element found
'XML_PARSER_CONTENT_IS_EMPTY' /* Is TRUE if element is empty
'XML_PARSER_ERROR_TEXT' /* error Message
'XML_PARSER_RESPONSE' /* Error NR; 0 = OK
*
*
DEFINE SUBROUTINE CALLBACK
IF XML_PARSER_CONTENT_IS_EMPTY THEN
IF XML_PARSER_XPATH_TYPE NE "T" AND XML_PARSER_XPATH_TYPE NE "/" THEN
COMPRESS XML_PARSER_XPATH "(NULL)" INTO OUT WITH DELIMITER "="
ELSE
OUT := XML_PARSER_XPATH
END-IF
ELSE
COMPRESS XML_PARSER_XPATH XML_PARSER_CONTENT INTO OUT WITH DELIMITER "="
END-IF
WRITE OUT
END-SUBROUTINE
/*
DEFINE SUBROUTINE PARSER_ERROR
OUT := XML_PARSER_ERROR_TEXT
WRITE OUT
END-SUBROUTINE
END
With a given result document from Tamino for the Employee data, the result of this program looks like this:
<?xml version="1.0" encoding="ISO-8859-1" ?> <Employee xmlns:ino="http://namespaces.softwareag.com/tamino/response2" ino:id="560" Personnel-ID="20006900"> <Full-Name> <First-Name>JOE</First-Name> <Name>ATHERTON</Name> </Full-Name> <Mar-Stat>S</Mar-Stat> <Sex>M</Sex> <Birth>1941-02-21</Birth> <Full-Address> <Address-Line>11603 HUNTERS GREEN</Address-Line> <Address-Line>SYRACUSE</Address-Line> <Address-Line>NY</Address-Line> <City>SYRACUSE</City> <Zip>13201</Zip> <Post-Code>13201</Post-Code> <Country>USA</Country> </Full-Address> <Telephone> <Phone>173-9859</Phone> <Area-Code>315</Area-Code> </Telephone> <Dept>TECH10</Dept> <Job-Title>ANALYST</Job-Title> <Income> <Curr-Code>USD</Curr-Code> <Salary>43000</Salary> </Income> <Income> <Curr-Code>USD</Curr-Code> <Salary>39500</Salary> </Income> <Income> <Curr-Code>USD</Curr-Code> <Salary>36700</Salary> </Income> <Income> <Curr-Code>USD</Curr-Code> <Salary>34400</Salary> </Income> <Income> <Curr-Code>USD</Curr-Code> <Salary>32600</Salary> </Income> <Leave-Data> <Leave-Due>19</Leave-Due> <Leave-Taken>4</Leave-Taken> </Leave-Data> <Leave-Booked> <Leave-Start>19980112</Leave-Start> <Leave-End>19980112</Leave-End> </Leave-Booked> <Leave-Booked> <Leave-Start>19980605</Leave-Start> <Leave-End>19980605</Leave-End> </Leave-Booked> <Leave-Booked> <Leave-Start>19980916</Leave-Start> <Leave-End>19980916</Leave-End> </Leave-Booked> <Lang>ENG</Lang> </Employee>
Anmerkung:
There is no line break in the whole document.
The result of the above Natural program looks like this:
?=xml version="1.0" encoding="ISO-8859-1" Employee Employee/@xmlns:ino=http://namespaces.softwareag.com/tamino/response2 Employee/@ino:id=560 Employee/@Personnel-ID=20006900 Employee/Full-Name Employee/Full-Name/First-Name Employee/Full-Name/First-Name/$=JOE Employee/Full-Name/First-Name// Employee/Full-Name/Name Employee/Full-Name/Name/$=ATHERTON Employee/Full-Name/Name// Employee/Full-Name// Employee/Mar-Stat Employee/Mar-Stat/$=S Employee/Mar-Stat// Employee/Sex Employee/Sex/$=M Employee/Sex// Employee/Birth Employee/Birth/$=1941-02-21 Employee/Birth// Employee/Full-Address Employee/Full-Address/Address-Line Employee/Full-Address/Address-Line/$=11603 HUNTERS GREEN Employee/Full-Address/Address-Line// Employee/Full-Address/Address-Line Employee/Full-Address/Address-Line/$=SYRACUSE Employee/Full-Address/Address-Line// Employee/Full-Address/Address-Line Employee/Full-Address/Address-Line/$=NY Employee/Full-Address/Address-Line// Employee/Full-Address/City Employee/Full-Address/City/$=SYRACUSE Employee/Full-Address/City// Employee/Full-Address/Zip Employee/Full-Address/Zip/$=13201 Employee/Full-Address/Zip// Employee/Full-Address/Post-Code Employee/Full-Address/Post-Code/$=13201 Employee/Full-Address/Post-Code// Employee/Full-Address/Country Employee/Full-Address/Country/$=USA Employee/Full-Address/Country// Employee/Full-Address// Employee/Telephone Employee/Telephone/Phone Employee/Telephone/Phone/$=173-9859 Employee/Telephone/Phone// Employee/Telephone/Area-Code Employee/Telephone/Area-Code/$=315 Employee/Telephone/Area-Code// Employee/Telephone// Employee/Dept Employee/Dept/$=TECH10 Employee/Dept// Employee/Job-Title Employee/Job-Title/$=ANALYST Employee/Job-Title// Employee/Income Employee/Income/Curr-Code Employee/Income/Curr-Code/$=USD Employee/Income/Curr-Code// Employee/Income/Salary Employee/Income/Salary/$=43000 Employee/Income/Salary// Employee/Income// Employee/Income Employee/Income/Curr-Code Employee/Income/Curr-Code/$=USD Employee/Income/Curr-Code// Employee/Income/Salary Employee/Income/Salary/$=39500 Employee/Income/Salary// Employee/Income// Employee/Income Employee/Income/Curr-Code Employee/Income/Curr-Code/$=USD Employee/Income/Curr-Code// Employee/Income/Salary Employee/Income/Salary/$=36700 Employee/Income/Salary// Employee/Income// Employee/Income Employee/Income/Curr-Code Employee/Income/Curr-Code/$=USD Employee/Income/Curr-Code// Employee/Income/Salary Employee/Income/Salary/$=34400 Employee/Income/Salary// Employee/Income// Employee/Income Employee/Income/Curr-Code Employee/Income/Curr-Code/$=USD Employee/Income/Curr-Code// Employee/Income/Salary Employee/Income/Salary/$=32600 Employee/Income/Salary// Employee/Income// Employee/Leave-Data Employee/Leave-Data/Leave-Due Employee/Leave-Data/Leave-Due/$=19 Employee/Leave-Data/Leave-Due// Employee/Leave-Data/Leave-Taken Employee/Leave-Data/Leave-Taken/$=4 Employee/Leave-Data/Leave-Taken// Employee/Leave-Data// Employee/Leave-Booked Employee/Leave-Booked/Leave-Start Employee/Leave-Booked/Leave-Start/$=19980112 Employee/Leave-Booked/Leave-Start// Employee/Leave-Booked/Leave-End Employee/Leave-Booked/Leave-End/$=19980112 Employee/Leave-Booked/Leave-End// Employee/Leave-Booked// Employee/Leave-Booked Employee/Leave-Booked/Leave-Start Employee/Leave-Booked/Leave-Start/$=19980605 Employee/Leave-Booked/Leave-Start// Employee/Leave-Booked/Leave-End Employee/Leave-Booked/Leave-End/$=19980605 Employee/Leave-Booked/Leave-End// Employee/Leave-Booked// Employee/Leave-Booked Employee/Leave-Booked/Leave-Start Employee/Leave-Booked/Leave-Start/$=19980916 Employee/Leave-Booked/Leave-Start// Employee/Leave-Booked/Leave-End Employee/Leave-Booked/Leave-End/$=19980916 Employee/Leave-Booked/Leave-End// Employee/Leave-Booked// Employee/Lang Employee/Lang/$=ENG Employee/Lang// Employee//
The parser does not handle:
Composition of a tag (incl. processing instruction). Only start-tag must be equal to end-tag (incl. processing instruction).
Example:
<.doc></.doc> <!-- invalid character in tag --> <doc><? ?></doc> <!-- invalid whitespace --> <doc>&#RE;</doc> <!-- invalid character in tag -->
Character or entity references
Example:
<doc>& no refc</doc> <!-- missing semicolon --> <doc a1=v1></doc> <!-- string literal expected -->
Exact handling of CDATA-Sections
Example:
<doc><![CDATA [ stuff]]></doc> <!-- must be CDATA[ -->
Content of an entity/processing instruction
Example:
<doc>]]></doc> <!-- ]] not allowed -->
Number of tags/attributes
Headerinformation
Unicode-charset (supports ISO-8859-1)