XML, COBOL and Application Modernization

Bringing XML to the application

IBM 2007

Tom Ross Nick Tindall Share Tampa February, 2007

Agenda

Some XML terminology Scenarios XML support in COBOL WebSphere Developer XSE

XML Services for the Enterprise

Discussion, questions

IBM 2007

Agenda...

Some XML terminology

IBM 2007

Some XML terminology

XML processing programs (parsers):

SAX - Simple API for XML

Callbacks

to your program for each XML event (document

fragment)

DOM - Document Object Model

In

effect the XML document becomes a miniature data base that supports navigation and simple queries

Well-formed XML document - basic grammar rules:

exactly one root element a matching end tag for every start tag elements properly nested, etc., etc. Well-formedness, plus... Element order and containment (structure constraints) Proper content (type constraints)
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Valid XML document (wrt a DTD or schema):

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Agenda...

Some XML terminology Scenarios

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Customer scenarios/problems - 1

Refacing existing applications/transactions

To allow non-traditional clients to use them A step towards componentization In particular to allow access as a Web Service Various transports/protocols Performance typically critical
B i n a r y I n t e r f a c e

Web
Interactive Voice Response

XML

Existing app (unmodified)

Adapter/ converter

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Customer scenarios/problems - 2

Inter-application communication

Need arises because of mergers/acquisitions, or Between different purchased applications Interfaces need only be compatible, not identical Allows schema evolution without synchronized updates Would previously have been done with file readers/writers Single Enterprise system/complex
Existing app-1
[Address space A]
B i n a r y I n t e r f a c e C o n v e r t e r B i n a r y I n t e r f a c e

Existing app-2
[Address space B]
or

C o n v e r t e r

XML

New app-2
[Address space B]

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Agenda...

Some XML terminology Scenarios XML support in COBOL

IBM 2007

Why process XML in applications?

Coherent development context and methodology Centralizes business logic within the application

Versus some business function here, some there, ...

Independent of middleware choices, characteristics Allows business logic to be conveniently applied during and after message acquisition/generation Incremental step from existing application design Can process XML messages as such

Versus forcing conversion to traditional data structures

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Why process XML in COBOL?

Keeps development control in one place/style Guarantees correct language semantics

sign configuration layout/padding picture constraints

Exploits your existing assets/skills/literacy Supports a variety of scenarios:

Converters, bridging to existing (unchanged) applications Direct use of XML in new or enhanced applications

High performance: CPU and elapsed time

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Enterprise COBOL XML support

Inbound XML parsing and outbound XML generation:

XML PARSE xml-doc PROCESSING PROCEDURE xml-handler XML GENERATE xml-doc FROM data-item COUNT IN char-count

XML parsing Much faster than general purpose parsers

Designed for high-speed transaction processing CICS, IMS, batch, TSO, USS, ... Use MQSeries, CICS transient queue or COMMAREA, IMS message processing queue, WebSphere, etc.

Runs in all COBOL run-time environments:

Works with any transport mechanism for XML documents

Provides basic SAX-style parsing Checks well-formedness (but not validity) XML Parser is part of the run-time library

Can be used from Enterprise COBOL or Enterprise PL/I

XML generation: Single statement transforms entire data structure (group)

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XML PARSE

Parses XML documents that are in memory, in a COBOL alphanumeric or national data item Discovers the individual pieces of XML documents

Passes each piece to user-written processing procedure

During parsing you can populate COBOL data structures with the data from XML messages

Advantage: non-COBOL programs can communicate data to/from COBOL without having to know the COBOL data structure formats!

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XML PARSE

XML PARSE statement

The COBOL interface to the high-speed XML parser XML-CODE: communicates status of parsing XML-EVENT: describes each event during parsing XML-TEXT: contains XML document fragments XML-NTEXT: contains NATIONAL XML doc fragments

XML special registers

XML PARSE XMLDOCUMENT PROCESSING PROCEDURE XMLEVENT-HANDLER END-XML ... XMLEVENT-HANDLER. EVALUATE TRUE WHEN XML-EVENT = 'START-OF-ELEMENT' AND XML-TEXT = 'TRADE DISPLAY 'Processing new stock trade ...
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Hello XML World inbound

Identification division. Program-id. HelloXML. Data division. Working-storage section. 1 M. 2 pic x(21) value '<?xml version="1.0"?>'. 2 pic x(40) value '<msg type="succinct">Hello, World!</msg>'. Procedure division. Display 'XML Event XML Text' XML Parse M Processing procedure P End-XML Goback. P. If XML-Code = 0 Display XML-Event XML-Text End-if. End program HelloXML.
XML Event START-OF-DOCUMENT VERSION-INFORMATION START-OF-ELEMENT ATTRIBUTE-NAME ATTRIBUTE-CHARACTERS CONTENT-CHARACTERS END-OF-ELEMENT END-OF-DOCUMENT
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XML Text <?xml version="1.0"?><msg type="succinct">Hello, World!</msg> 1.0 msg type succinct Hello, World! msg

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XML GENERATE FROM

Generates a complete XML document:

Into an alphanumeric or national data item From a group or elementary item Trailing spaces removed from alphanumeric values (leading spaces from right-justified items) Leading zeroes removed from numeric values

Data values are trimmed:

XML tag names are the mixed-case data names Supports all data types except -pointer and object reference Unnamed and redefining items are ignored For more details see V3.4 Programming Guide:

www.ibm.com/software/awdtools/cobol/zos/library/
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Hello XML World outbound

Identification division. Program-id. HelloXML. Data division. Working-storage section. 1 Hello-doc pic x(200). 1 Greeting. 2 msg pic x(100) value 'Hello, World! '. 1 Num-chars pic 999. Procedure division. XML Generate Hello-doc From Greeting Count in Num-chars Display '|' Hello-doc(1:Num-chars) '|' Goback. End program HelloXML.

|<Greeting><msg>Hello, World!</msg></Greeting>|

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Hello XML World outbound

1 Hello-doc pic x(200). 1 Greeting-Grp. 2 Contact-info. 3 Name PIC x(20) Value 'Tom'. 3 Addr PIC x(18) Value '555 Bailey Ave'. 3 Telephone PIC 9(12) Value 4084634242. 2 Contact-redef REDEFINES Contact-info. 3 Junk PIC X(50). 2 msg pic x(100) value 'Hello, World! '. 1 Greeting-redef REDEFINES Greeting-Grp. 2 Name PIC x(20). 2 PIC x(18). 2 Phone PIC 9(12). 2 Short-Msg PIC X(10). 1 Num-chars binary pic 9(9).

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Hello XML World outbound

XML Generate Hello-doc From Greeting-grp Count in Num-chars <Greeting-grp> <Contact-info> <Name>Tom</Name> <Addr>555 Bailey Ave</Addr> <Telephone>4084634242</Telephone> <msg>Hello, World!</msg> </Contact-info> </Greeting-grp> XML Generate Hello-doc From Greeting-redef Count in Num-chars <Greeting-redef> <Name>Tom</Name> <Phone>4084634242</Phone> <Short-Msg>Hello, World!</Short-Msg> </Greeting-redef>
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Agenda...

Some XML terminology Scenarios XML support in COBOL WebSphere Developer for zSeries (WD for z) XML Services for the Enterprise (XSE)

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What is WD XSE?

Allows COBOL applications to consume and produce XML messages Leverages XML parsing capabilities of IBM Enterprise COBOL V3 Creates:

Inbound converter program, to convert XML messages into native COBOL data Outbound converter program, to convert native COBOL data into XML messages Sample COBOL driver program:
Illustrates

the invocation of converters Illustrates the interaction with existing application Needs to be modified before use

XML Schema, for validation and generating samples

Input

to the Web Service Description (WSDL)

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Enables communication with XML-based systems

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WD XSE

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Web Service Runtime and Scenario Selection dialog Create New Service Interface (bottom-up) wizard Compiled XML conversion type Language structures page Generation options page BIDI conversion options dialog Runtime specific pages Web Services for CICS page IMS SOAP Access page File, data set or member selection Interpretive XML conversion type (bottom-up) CICS Web Services Assistant pages (bottom-up) Create New Service Implementation (top-down) wizard Interpretive XML conversion type (top-down) CICS Web Services Assistant pages (top-down) Map to an Existing Service Interface (meet-in-the-middle) Mapping Converter Generator wizard Generating artifacts remotely
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WD XSE
Web Service Runtime and Scenario Selection dialog
Select artifact then File->New->Other
OR Enable Enterprise Web service from pop-up menu

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Web Service Runtime and Scenario Selection dialog

Start the appropriate XSE wizard for selected combination of target runtime, web service development scenario and XML conversion technology type.

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Web Service Runtime and Scenario Selection dialog

Supported Runtimes Web Services for CICS (CICS TS 3.1) SOAP for CICS (CICS TS 2.2/2.3/3.1) IMS SOAP Gateway Batch, TSO and USS
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Web Service Runtime and Scenario Selection dialog

Scenario name Create New Service Interface Map an Existing Service Interface Create New Service Implementation

Scenario nick-name Bottom-up Meet-in-middle Top-down

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Web Service Runtime and Scenario Selection dialog

Supported Conversion Types Compiled XML Conversion Interpretive XML Conversion (CICS TS 3.1)

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Web Service Runtime and Scenario Selection dialog

Help on the XML Conversion technology type is available. Interpretive is only available for Web Services for CICS runtime.

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Web Service Runtime and Scenario Selection dialog

To learn about the Runtimes, Scenarios and Conversion types, refer to the WD/z online help. Note that not all possible combinations are supported. The WD/z online help has a table of the supported combinations.

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Create New Service Interface (bottom-up) wizard

Compiled XML conversion type Common pages

SOAP for CICS Batch, TSO, and USS

Web services for CICS IMS SOAP Gateway

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RUNTIME SPECIFIC PAGES

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Create New Service Interface (bottom-up) wizard Compiled XML conversion type Runtime specific pages
Web services for CICS IMS SOAP Gateway

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Create New Service Interface (bottom-up) wizard

Interpretive XML conversion type CICS Web Services Assistant pages (bottom up)

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Create New Service Implementation (top-down) wizard

Interpretive XML conversion type CICS Web Services Assistant pages (top-down)

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Map to an Existing Service Interface (meet-in-the-middle) Generate Conversion Code for mapping

You start Mapping Converter Generator wizard from Web Service Runtime selection dialog (similar to the Create New Service Interface (bottom-up) wizard) Even though you specify the Runtime when you create the Mapping session file, that information does not persist after creation of the mapping file.

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Map to an Existing Service Interface (meet-in-the-middle)

Mapping Converter Generator wizard (Outbound mapping)

Web services for CICS

Common

Common

SOAP for CICS Batch, TSO, and USS

IMS SOAP Gateway

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Map to an Existing Service Interface (meet-in-the-middle)

Mapping Converter Generator wizard (Inbound mapping)

Web services for CICS

Common

Common

SOAP for CICS Batch, TSO, and USS

IMS SOAP Gateway

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Example XML and COBOL data structure

<?xml version="1.0"?> 01 USEDCAR. <usedcar> 05 PRICE COMP-3 PIC 9(5)V99. <price>9,347.99</price> 05 SUMMARY. <make>AMC</make> 10 MAKE PIC X(36). <model>Gremlin</model> 10 MODEL PIC X(44). <vin>GV39JFGLKM09Y</vin> 10 VIN PIC X(13). <color>Red</color> 10 COLOR PIC X(10). <mileage>39,000</mileage> 88 RED VALUE 'Red'. <inscode>I</inscode> 88 WHITE VALUE 'White'. <numclaims>1</numclaims> 88 BLUE VALUE 'Blue'. <claim> 05 HISTORY. <claimno>S8430M4D20030226</claimno> 10 MILEAGE PIC 9(6). <claimamt>1,234</claimamt> 10 INSCODE PIC X. <insurer>IndemnitiesAreWe</insurer> 10 NUMCLAIMS BINARY PIC 9. <details>Engine fell out</details> 10 CLAIMS. </claim> 15 CLAIM OCCURS 0 TO 9 TIMES </usedcar> DEPENDING ON NUMCLAIMS. 20 CLAIMNO PIC X(16). 20 CLAIMAMT BINARY PIC 9(5). 20 INSURER PIC X(39). 20 DETAILS PIC X(100). Used car information: Price Make Model VIN Color Mileage InsCode NumClaims 0934799 AMC Gremlin GV39JFGLKM09Y Red 039000 I 1 ClaimNo ClaimAmt Insurer Details S8430M4D20030226 01234 IndemnitiesAreWe Engine fell out 36

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Pros and cons: WD XSE versus direct COBOL coding

WD XSEstrengths:

Interactive tool avoids intricate and laborious programming

Easy

to reface existing COBOL applications to support XML and outbound

Wholesale conversion between documents and structures

inbound

Robust error recovery, using LE services Highly optimized and sophisticated content processing
Uses

the native z/OS high-speed parser

Unnecessary elements are conveniently ignored Can derive XML definition from COBOL, or match independent XML and COBOL definitions Generated schema can be used to validate messages and as input to the WSDL file

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Pros and cons: WD XSE versus direct COBOL coding

XML PARSEstrengths:

Flexibility: all parts of an XML document are accessible:

Attributes,

processing instructions, comments, etc.

Business logic can be conveniently applied during and after message acquisition/generation XML definition can be independent of (any) data structure Can short-circuit parsing early after required input is seen

XML GENERATEFROMstrengths:

Very simple to use A single COBOL statement provides wholesale conversion from a data structure to a document The generated XML precisely matches the data structure Redefinition allows selective output, different tag names
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Agenda...

Some XML terminology Scenarios XML support in COBOL WebSphere StudioXML Enablement Discussion, questions

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Sample XML parse program...

Process flag(i,i) Identification division. Program-id. xmldump. Environment division. Input-output section. File-control. select xf assign fi file status fs. Data division. File section. FD xf recording mode v record varying from 1 to 1024 characters depending on l. 1 r. 2 pic x occurs 1 to 1024 times depending on l. Working-storage section. 1 ft. 2 pic x(5) value ') SHR'. 2 pic x value low-value. Local-storage section. 1 fv. 2 pic x(7) value 'FI=DSN('. 2 fn pic x(150). 1 in-len binary pic 999. 1 st pic x(9). 1 rc binary pic 9(9). 1 l binary pic 9(5). 1 p binary pic 9(5). 1 fs pic 99. 1 xml-document pic x(32767).
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Procedure division. mainline section. perform get-doc perform until in-len = 0 if p > 0 xml parse xml-document(1:p) processing procedure xml-handler on exception display 'XML document error ' xml-code not on exception display 'XML document successfully parsed' end-xml end-if perform get-doc end-perform goback . get-fn section. display ' Enter XML document file name or SYSIN (null to end)' move space to fn move 0 to tally accept fn inspect function reverse(fn) tallying tally for leading space compute in-len = 150 - tally .

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get-doc section. perform get-fn evaluate true when in-len = 0 continue when fn(1:in-len) = 'SYSIN' display ' Enter XML document:' move spaces to xml-document(1:150) accept xml-document(1:150) move function lower-case(xml-document(1:150)) to xml-document(1:150) move 0 to p inspect function reverse(xml-document(1:150)) tallying p for leading spaces compute p = 150 - p when other move ft to fn(in-len + 1:length of ft) call 'putenv' using by value address of fv returning rc if rc not = 0 display 'putenv failed with rc = ' rc '.' stop run end-if open input xf if fs = 0 read xf end-if move 1 to p perform until fs not = 0 if p - 1 + length of r > length of xml-document display 'XML document is larger than the document ' 'buffer (' length of xml-document ' bytes).' move 13 to fs else string r delimited by size into xml-document with pointer p read xf end-if end-perform evaluate fs when 10 subtract 1 from p when 13 move 0 to p when other display 'Some catastrophe on file ' fn(1:in-len) '; status = ' fs '.' move 0 to p end-evaluate close xf end-evaluate 42 .

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xml-handler section. evaluate xml-event when 'START-OF-DOCUMENT' compute rc = function length(xml-text) move rc to st call 'nzp' using st l display ' ' display 'Start of document: length=' st(l:) ' characters.' when 'END-OF-DOCUMENT' display 'End of document.' display ' ' when 'VERSION-INFORMATION' display 'Version: <' xml-text '>' when 'ENCODING-DECLARATION' display 'Encoding: <' xml-text '>' when 'STANDALONE-DECLARATION' display 'Standalone: <' xml-text '>' when 'START-OF-ELEMENT' display 'Start element tag: <' xml-text '>' when 'ATTRIBUTE-NAME' display 'Attribute name: <' xml-text '>' when 'ATTRIBUTE-CHARACTERS' display 'Attribute value characters: <' xml-text '>' when 'ATTRIBUTE-CHARACTER' display 'Attribute value character: <' xml-text '>' when 'END-OF-ELEMENT' display 'End element tag: <' xml-text '>' when 'START-OF-CDATA-SECTION' display 'Start of CData: <' xml-text '>' when 'END-OF-CDATA-SECTION' display 'End of CData: <' xml-text '>' when 'CONTENT-CHARACTERS' display 'Content characters: <' xml-text '>' when 'CONTENT-CHARACTER' display 'Content character: <' xml-text '>' when 'PROCESSING-INSTRUCTION-TARGET' display 'PI target: <' xml-text '>' when 'PROCESSING-INSTRUCTION-DATA' display 'PI data: <' xml-text '>' when 'COMMENT' display 'Comment: <' xml-text '>' when 'EXCEPTION' compute rc = function length (xml-text) move rc to st call 'nzp' using st l display 'Exception ' xml-code ' at offset ' st(l:) '.' when other display 'Unexpected xml event: ' xml-event '.' end-evaluate . End program xmldump.

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Identification division. Program-id. nzp. Data division. Linkage section. 1 str pic x(9). 1 pos binary pic 9(5). Procedure division using str pos. if str = '000000000' move 9 to pos else move 0 to pos inspect str tallying pos for leading '0' add 1 to pos end-if goback . End program nzp.

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Sample XML generate program...

Identification division. Program-id. XGFX. Data division. Working-storage section. 01 numItems pic 99 global. 01 purchaseOrder global. 05 orderDate pic x(10). 05 shipTo. 10 country pic xx value 'US'. 10 name pic x(30). 10 street pic x(30). 10 city pic x(30). 10 state pic xx. 10 zip pic x(10). 05 billTo. 10 country pic xx value 'US'. 10 name pic x(30). 10 street pic x(30). 10 city pic x(30). 10 state pic xx. 10 zip pic x(10). 05 orderComment pic x(80). 05 items. 10 item occurs 0 to 20 times depending on numItems. 15 partNum pic x(6). 15 productName pic x(50). 15 quantity pic 99. 15 USPrice pic 999v99. 15 shipDate pic x(10). 15 itemComment pic x(40). 01 numChars comp pic 999. 01 xmlPO pic x(999).

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Procedure division. m. Move 20 to numItems Move spaces to purchaseOrder Move '1999-10-20' to orderDate Move Move Move Move Move Move Move Move Move Move Move Move Move 'US' to country of shipTo 'Alice Smith' to name of shipTo '123 Maple Street' to street of shipTo 'Mill Valley' to city of shipTo 'CA' to state of shipTo '90952' to zip of shipTo 'US' to country of billTo 'Robert Smith' to name of billTo '8 Oak Avenue' to street of billTo 'Old Town' to city of billTo 'PA' to state of billTo '95819' to zip of billTo 'Hurry, my lawn is going wild!' to orderComment

Move 0 to numItems Call 'addFirstItem' Call 'addSecondItem' Move space to xmlPO Xml generate xmlPO from purchaseOrder count in numChars Call 'pretty' using xmlPO value numChars Goback.

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Identification division. Program-id. 'addFirstItem'. Procedure division. Add 1 to numItems Move '872-AA' to partNum(numItems) Move 'Lawnmower' to productName(numItems) Move 1 to quantity(numItems) Move 148.95 to USPrice(numItems) Move 'Confirm this is electric' to itemComment(numItems) Goback. End program 'addFirstItem'. Identification division. Program-id. 'addSecondItem'. Procedure division. Add 1 to numItems Move '926-AA' to partNum(numItems) Move 'Baby Monitor' to productName(numItems) Move 1 to quantity(numItems) Move 39.98 to USPrice(numItems) Move '1999-05-21' to shipDate(numItems) Goback. End program 'addSecondItem'. End program XGFX.

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Identification division. Program-id. Pretty. Data division. Working-storage section. 01 prettyPrint. 05 pose pic 999. 05 posd pic 999. 05 depth pic 99. 05 element pic x(30). 05 indent pic x(20). 05 buffer pic x(100). Linkage section. 1 doc. 2 pic x occurs 16384 times depending on len. 1 len comp-5 pic 9(9). Procedure division using doc value len. m. Move space to prettyPrint Move 0 to depth posd Move 1 to pose Xml parse doc processing procedure p Goback.

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p. Evaluate xml-event When 'START-OF-ELEMENT' If element not = space If depth > 1 Display indent(1:2 * depth - 2) buffer(1:pose - 1) Else Display buffer(1:pose - 1) End-if End-if Move xml-text to element Add 1 to depth Move 1 to pose String '<' xml-text '>' delimited by size into buffer with pointer pose Move pose to posd When 'CONTENT-CHARACTERS' String xml-text delimited by size into buffer with pointer posd When 'CONTENT-CHARACTER' String xml-text delimited by size into buffer with pointer posd When 'END-OF-ELEMENT' Move space to element String '</' xml-text '>' delimited by size into buffer with pointer posd If depth > 1 Display indent(1:2 * depth - 2) buffer(1:posd - 1) Else Display buffer(1:posd - 1) End-if Subtract 1 from depth Move 1 to posd When other Continue End-evaluate. End program Pretty.

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Output from generate program

<purchaseOrder> <orderDate>1999-10-20</orderDate> <shipTo> <country>US</country> <name>Alice Smith</name> <street>123 Maple Street</street> <city>Mill Valley</city> <state>CA</state> <zip>90952</zip> </shipTo> <billTo> <country>US</country> <name>Robert Smith</name> <street>8 Oak Avenue</street> <city>Old Town</city> <state>PA</state> <zip>95819</zip> </billTo> <orderComment>Hurry, my lawn is going wild!</orderComment>

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<items> <item> <partNum>872-AA</partNum> <productName>Lawnmower</productName> <quantity>1</quantity> <USPrice>148.95</USPrice> <shipDate> </shipDate> <itemComment>Confirm this is electric</itemComment> </item> <item> <partNum>926-AA</partNum> <productName>Baby Monitor</productName> <quantity>1</quantity> <USPrice>39.98</USPrice> <shipDate>1999-05-21</shipDate> <itemComment> </itemComment> </item> </items> </purchaseOrder>

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