An Introduction to XML Technologies and Standards for Futures and Options Industry Professionals

1
An Introduction to XML Technologies and Standards
for Futures and Options Industry Professionals

• Presented by
• The Futures Industry Association Standards
  Working Group
• in conjunction with The Fix Protocol Ltd. Global
  Derivatives Committee

2
Agenda - Morning

• Welcome 900am
• Angela Krug, Deutsche Bank AG
• XML The Crash Course, part 1 905am
• Why XML? Why Now?
• Ed Gogol, Chicago Mercantile Exchange
• What is XML? What is a well defined XML message?
• Jim Northey, The FIX Global Derivatives Committee
• Break 1015am
• XML The Crash Course Part 2 1030am
• How are XML messages defined and validated?
• Jim Northey, The FIX Global Derivatives Committee
• XML The Benefits 1115am
• How are XML Messages accessed from an application
  program?
• Oren Miller, ThoughtWorks, Inc.
• Accessing XML Messages 1145am
• How are XML messages accessed from application
  programs?
• Matt Simpson, Chicago Mercantile Exchange

3
Agenda - Afternoon

• Lunch 1230pm
• Implementing XML Based Solutions 115pm
• David Li, Chief Architect, New York Mercantile
  Exchange
• Elliot Napakh, Technical Architect, New York
  Mercantile Exchange
• Question and answers
• The CME Pilot Project using FIXML 200pm
• Matt Simpson - Chicago Mercantile Exchange
• Questions and answers
• Break 300pm
• What Standards Exist for Derivatives Markets?
  315pm
• Jim Northey, The FIX Global Derivatives Committee
• Conclude 400pm

4
Welcome

• Chicago John Munro
• Senior Vice President Product Development, Rolfe
  Nolan
• Chairman, FIA Standards Working Group
• New York Angela Krug
• Vice President, Deutsche Bank AG
• Vice Chairman, FIA Standards Working Group
• Thanks to our hosts
• Chicago - The Chicago Board of Trade - Tom McCabe
• New York - Salomon Smith Barney - Mike Mortkowitz
• Why are we here?
• Presenters
• Jim Northey - FIX Protocol Limited
• Matt Simpson - Chicago Mercantile Exchange
• Oren Miller - Thoughtworks, Inc.
• David Li - New York Mercantile Exchange
• Elliot Napakh - New York Mercantile Exchange

5
XML The Crash Course

• Ed Gogol,
• Director, Systems Development, Clearing House,
  Chicago Mercantile Exchange

Jim Northey Chair, FIX Protocol Ltd. Global
Derivatives Committee
6
XML The Crash Course

• Introduction to XML by Ed Gogol
• Why XML? Why Now?
• XML Basics
• Well Formed XML Documents
• Describing XML Documents
• Document Type Definitions
• XML Schema
• Namespaces
• XML Path

7
Why XML? Why Now? Advantages

• Technology is easily integrated
• Focus on integration
• Wide adoption across computer vendors
• Ability to interoperate across standards

8
What is XML?
Its a Dessert Topping!!
XML
Its A Floor Wax!!
The BEST NEW thing since RDBMS and Objects!!!
9
What is XML?
1980s

• History
• Move beyond the closed markup language HTML to
  add semantic
• eXtensible Markup Language
• Open ended mark up language
• XML is a Meta markup language
• Markup language used to create other markup
  languages
• Just like HTML uses Tags to organize data
• The tags describe the content of the message
• Self describing data
• Description of the message with the message
  provides for considerable flexibility

SGML
1994
HTML
1998
XML
1999
XHTML
http//www.w3.org/XML/1999/XML-in-10-points
10
Driving force behind XML

• W3C - World Wide Web Consortium
  http//www.w3c.org
• founded in October 1994 to lead the World Wide
  Web to its full potential by developing common
  protocols that promote its evolution and ensure
  its interoperability. Today, W3C has over 450
  Members and nearly 70 full-time staff around the
  world who contribute to the development of W3C
  specifications and software.
• http//www.w3.org/Consortium/Points/

11
HTML - A Closed Markup Language
ltHTMLgt ltHEADgt ltTITLEgtFutures Industry Association
- The FIA is the only association representative
of all organizations that have an interest in the
futures market.lt/TITLEgt lt/HEADgt ltBODY
BGCOLOR"333333" ALINK000000 VLINKE9E7A7
LINKE9E7A7 TOPMARGIN0 LEFTMARGIN0
RIGHTMARGIN0 BOTTOMMARGIN0 MARGINHEIGHT0
MARGINWIDTH0gt ltDIV ALIGN"center"gtltPgtnbspltPgtn
bspltPgt lt!-- START LOGO TABLE --gt ltTABLE
BORDER0 WIDTH770 CELLPADDING0
CELLSPACING0gt ltTR HEIGHT65gt ltTD
ALIGNcentergtltSTRONGgtltFONT SIZE3
COLORffff00gtwww.futuresindustry.orglt/FONTgtlt/STRO
NGgtltBRgtltFONT SIZE5 COLORwhitegtFUTURES INDUSTRY
ASSOCIATIONlt/EMgtlt/FONTgtlt/TDgt lt/TRgt lt/TABLEgt lt!--
END LOGO TABLE --gt ... ltFONT SIZE1
COLOR333333gtThe Futures Industry Association
and the Futures Industry Institute. Futures,
Markets, Volume, CFTC, SEC, Trade, Show, Boca,
Electronic, Trading, Expo, Exhibit, Education,
Optech, Market, Commission, Merchant, Finance,
FCM, Commodities, Commodity, Trading, Advisor,
CTA, Derivatives, Risk, Management, Options,
Hedge, Trading, y2k, FII, FIA, De-regulation,
Regulation, Contract, Specifications, Clearing,
Series, 31, 32, 33, Alternative, Investments,
Ethics, Factbook, Data, Investor,
Managedlt/FONTgt lt/DIVgt lt/BODYgt lt/HTMLgt
12
A note on terminology

• In this presentation XML Message and XML
  Document are used interchangeably

13
Quick Overview on XML

• An XML Document or Message is made up of Elements
• Elements are composed of
• All tags contain a name
• An Opening Tag
• optional attributes
• optional content
• A Closing Tag
• Elements can be empty
• Meaning the Opening Tag can be terminated with a
  backslash character
• Elements are nested
• Elements can contain other elements containing
  other elements .
• Forms a tree of information
• White space is ignored with the exception of the
  information between the element opening tag and
  closing tag

• ltThisIsAn-ElementNamegt this is the data
• for this element
• lt/ThisIsAn-ElementNamegt
• ltAnEmpty_ElementLooksLikeThis/gt
• ltAnyOldElementgt
• ltAnyOldNestedElementHeregt
• ltAnotherElementgt
• lt/AnotherElementgt
• lt/AnyOldNestedElementHeregt
• lt/AnyOldElementgt
• ltRejectReasongtCustomer Unknownlt/RejectReasongt
• ltRejectReasongtCustomer Unknownlt/RejectReasongt

14
Well Formed XML Messages

• There are only a handful of rules that need to be
  followed to create XML messages
• XML messages that follow the simple rules are
  considered to be

Well Formed XML Messages
Well Formed Messages are good
A Well Formed XML document is not to be confused
with a Valid XML document
15
Anatomy of an XML Message
XML Declaration
lt?xml version'1.0'?gt ltFIXMLgt ltFIXMLMessagegt
ltApplicationMessagegt ltOrdergt
ltClOrdIDgt12345lt/ClOrdIDgt ltHandlInst
Value"1"/gt ltInstrumentgt
ltSecuritygt ltSymbolgtEKlt/Symbolgt
lt/Securitygt lt/Instrumentgt
ltSide Value"1"/gt ltOrderQuantitygt
ltOrderQtygt10000lt/OrderQtygt
lt/OrderQuantitygt ltOrderTypegt
ltMarketOrder OrdType"1"/gt lt/OrderTypegt
ltCurrency Value"USD"/gt lt/Ordergt
lt/ApplicationMessagegt lt/FIXMLMessagegt lt/FIXMLgt
Root Element
Empty Tag
Opening Tag
Attribute Value
Value
Element
Attribute
Closing Tag
Nested Elements
Whats This?
16
XML Declaration

• First line in XML document
• Delimited by lt? and ?gt
• Three properties that you can set
• version
• Always use this property
• There is only one version now 1.0
• encoding
• Use if you require support of an alternative
  character set
• Usually not needed
• Default character set is UTF-8, which is the
  ASCII part of Unicode
• standalone
• Use this property to tell an XML processor if
  there are other files required to process this
  XML document
• Valid values yes or no

17
XML Declaration Examples
Which of the following are well-formed?
_____ lt?xml version1.0 ?gt _____ lt?xml
version1.0 ?gt _____ lt?xml version1.0
?gt _____ lt?xml version 1.0 ?gt _____ lt?xml
version ?gt _____ lt?xml version1gt _____ lt?xml
version1.0 encodingUSASCII ?gt _____ lt?xml
version1.0 encodingUTF-8?gt _____ lt?xml
version1.0 standaloneyes ?gt _____ lt?xml
version1.0 encodingUTF-8 standaloneno
?gt _____ lt?xml version1.0 encodingUTF-8
standaloneNO ?gt
18
XML Declaration Examples
Which of the following are well-formed?
_____ lt?xml version1.0 ?gt _____ lt?xml
version1.0 ?gt _____ lt?xml version1.0
?gt _____ lt?xml version 1.0 ?gt _____ lt?xml
version ?gt _____ lt?xml version1gt _____ lt?xml
version1.0 encodingUSASCII ?gt _____ lt?xml
version1.0 encodingUTF-8?gt _____ lt?xml
version1.0 standaloneyes ?gt _____ lt?xml
version1.0 encodingUTF-8 standaloneno
?gt _____ lt?xml version1.0 encodingUTF-8
standaloneNO ?gt
19
Elements

• Have an Opening Tag and a Closing Tag
• XML Elements are nested - into a tree structure
• The outer most (top level) element is called the
  Root Element
• Content for the element is contained between the
  Opening Tag and the Closing Tag
• Tag names (element names)
• cannot have embedded spaces or punctuation
  characters other than - and _
• are case sensitive

lt?xml version'1.0' encoding "UTF-8"
standalone 'no' ?gt ltour_root_elementgt
ltour_main_element/gt ltelement-names-can-be-very-l
ong-indeed-as-this-one-is-here_notice-that_hyphens
-and_underscores_workgt lt/element-names-can-be-very
-long-indeed-as-this-one-is-here_notice-that_hyphe
ns-and_underscores_workgt lt/our_root_elementgt
20
Element Examples
Which of the following are well-formed?
_____ ltThis isAWellFormedElementgtltThis
isAWellFormedElementgt _____ ltIsThis-WellFormed__?
gtdata herelt/IsThis-WellFOrmed__? gt _____
ltPosnRpt/gt _____ ltThisIsAVeryLongElementNameIsItTo
oLongToBeUsed/gt _____ ltAutomobilegtChevroletlt/autom
obilegt _____ ltAmount100gtlt/Amountgt _____ ltMy
Car!gtChevroletlt/My Car!gt
21
Element Examples
Which of the following are well-formed?
_____ ltThis isAWellFormedElementgtltThis
isAWellFormedElementgt _____ ltIsThis-WellFormed__?
gtdata herelt/IsThis-WellFOrmed__? gt _____
ltPosnRpt/gt _____ ltThisIsAVeryLongElementNameIsItTo
oLongToBeUsed/gt _____ ltAutomobilegtChevroletlt/autom
obilegt _____ ltAmount100gtlt/Amountgt _____ ltMy
Car!gtChevroletlt/My Car!gt
22
Attributes

• Can be added to the Opening Tag of an Element
• namevalue or namevalue format
• White space ignored
• name value
• No embedded spaces or punctuation in an attribute
  name
• except - and _
• IMHO Think of elements as objects, think of
  attributes as urrrr..., well attributes of the
  objects (elements)
• Sometimes objects contain other objects
  (elements)
• Sometimes they just have attributes (data
  elements, member variables)
• In fact the ISO 15022 Working Group 10 creating
  ISO/XML uses object modeling (UML) to create
  their XML definitions

23
Attribute Examples
Which of the following are well-formed?
_____ ltInst CFI"FXXPSX" CVF"400" Ccy"USD"
Exch"CME" ID"48" MatDt"2002-12"
StlDt"2002-12-31"/gt _____ ltInst CFI"FXXPSX"
CVF400 Ccy"USD" Exch"CME" ID48
MatDt"2002-12" StlDt"2002-12-31"/gt _____
ltPartiesgt ltPty ID"CME" R"21"/gt ltPty
ID"560" R"4"/gt ltPty ID"560" R"27"
Typ"1"/gt lt/Partiesgt _____ ltInst Symbol
IBM" /gt _____ ltInst Symbol IBM" /gt
24
Attribute Examples
Which of the following are well-formed?
_____ ltInst CFI"FXXPSX" CVF"400" Ccy"USD"
Exch"CME" ID"48" MatDt"2002-12"
StlDt"2002-12-31"/gt _____ ltInst CFI"FXXPSX"
CVF400 Ccy"USD" Exch"CME" ID48
MatDt"2002-12" StlDt"2002-12-31"/gt _____
ltPartiesgt ltPty ID"CME" R"21"/gt ltPty
ID"560" R"4"/gt ltPty ID"560" R"27"
Typ"1"/gt lt/Partiesgt _____ ltInst Symbol
IBM" /gt _____ ltInst Symbol IBM" /gt
25
Comments

• Comments start with lt!-- and end with --gt
• Comments can appear anywhere in the XML message

Which of the following are well-formed?
_____ lt--! this is my comment--gt _____
lt!----------------------gt _____ lt!-- No this is a
good comment --gt _____ lt!-- this one is a lengthy
comment goes on for more than one line --gt
26
Comments

• Comments start with lt!-- and end with --gt
• Comments can appear anywhere in the XML message

Which of the following are well-formed?
_____ lt--! this is my comment--gt _____
lt!----------------------gt _____ lt!-- No this is a
good comment --gt _____ lt!-- this one is a lengthy
comment goes on for more than one line --gt
27
CDATA Sections

• Sometimes you just need to not parse something -
  you have special characters - such as code
  examples or even XML

lt!CDATA text gt
28
What tools can be used to edit XML documents

• Low end - what ever you have on your PC
• Notepad
• Internet Browser
• Microsoft Internet Explorer
• Netscape Navigator
• Open Source
• Xerlin http//www.xerlin.org
• Commercial Editors
• XML Spy
• XML Pro Edit
• There are many, many products out there to choose
  from

NEW
29
Lets revisit our example...
lt?xml version'1.0'?gt lt!DOCTYPE FIXML SYSTEM
'fixmlmain.dtd'gt ltFIXMLgt ltFIXMLMessagegt
ltApplicationMessagegt ltOrdergt
ltClOrdIDgt12345lt/ClOrdIDgt ltHandlInst
Value"1"/gt ltInstrumentgt
ltSecuritygt ltSymbolgtEKlt/Symbolgt
lt/Securitygt lt/Instrumentgt
ltSide Value"1"/gt ltOrderQuantitygt
ltOrderQtygt10000lt/OrderQtygt
lt/OrderQuantitygt ltOrderTypegt
ltMarketOrder OrdType"1"/gt lt/OrderTypegt
ltCurrency Value"USD"/gt lt/Ordergt
lt/ApplicationMessagegt lt/FIXMLMessagegt lt/FIXMLgt
Document Type Declaration
30
Document Type Declarations

• Delimited with lt!DOCTYPE and gt
• Follows the XML Declaration lt!XML version1.0 gt

lt!DOCTYPE root-element uri-of-dtd
internal-subset gt lt!DOCTYPE fixml SYSTEM
fixml4.3v20029020.dtdgt
31
Entities

• XML also provides entities which act placeholders
• kind of like variables a little bit
• Kind of like C defines and includes
• Two types
• General Entities
• Place holders for any content that occurs at the
  level of or inside the root element
• Parameter Entities (ignore these for now)

32
Entities


ENTITIES
name
name
General
Parameters
Character
Unparsed
Mixed Content
Internal
External
predefined
numbered
named
Internal
External
33
Character Entities

• If / gt lt are all special characters in XML,
  how can we get these to appear in our XML
  documents?
• By the use of predefined character entities
• amp
• apos
• gt gt
• lt lt
• quot
• What would the following produce as output from
  an XML document
• ltaposampaposgt

34
The answer

• ltaposampaposgt
• becomes
• ltgt

35
Numbered character entities

• 231
• xF9
• Represents the characters position within the
  Unicode character set
• Named Character Entities have nmeumonic name for
  specific characters

36
Using Entities
lt?xml version"1.0" encoding"UTF-8" ?gt lt!DOCTYPE
EntityExample lt!ENTITY CoAcr "SSB"gt lt!ENTITY
CoName "Salomon Smith Barney"gt gt ltEntityExamplegt
CoAcr CoName lt/EntityExamplegt
lt?xml version"1.0" encoding"UTF-8" ?gt
lt!DOCTYPE EntityExample (View Source for full
doctype...)gt ltEntityExamplegtSSB Salomon Smith
Barneylt/EntityExamplegt
NEW
37
Mixed Content Entities

• Defined as part of the lt!DOCTYPE gt document type
  declaration
• From our example
• Internal
• think define
• Everywhere that exch appears - the text CBOT
  would be replaced
• Everywhere that exname appears - the text
  Chicago Board of Trade would be replaced
• External
• think include
• Everywhere that disclosure appears - the
  contents of the file disclosure.txt would be read
  and substituted

lt!DOCTYPE fixml SYSTEM fixml.dtd lt!ENTITY
CoAcr SSBgt lt!ENTITY CoName Salomon Smith
Barneygt lt!ENTITY disclosure SYSTEM
disclosure.txtgt gt
NEW
38
An Example Mixed Content Entities
lt?xml version"1.0" encoding"UTF-8" ?gt lt!DOCTYPE
EntityExample lt!ENTITY CoAcr "SSB"gt lt!ENTITY
CoName "Salomon Smith Barney"gt lt!ENTITY
Disclosure SYSTEM "disclosure.txt"gt gt ltEntityExam
plegt CoAcr CoName quotDisclosurequot lt/
EntityExamplegt
lt?xml version"1.0" encoding"UTF-8" ?gt
lt!DOCTYPE EntityExample (View Source for full
doctype...)gt ltEntityExamplegtSSB Salomon Smith
Barney This is a standard disclosure file that
contains all of the legalize required on each and
every document as we have become a quite
litigious society and failure to include such
disclaimers in our documents will most certainly
lead to unwanted incursion of legal expenses.
Therefore, we must include these disclaimers,
even though they are seldom read and still will
not prevent litigation under the right
circumstance.lt/EntityExamplegt
NEW
39
Defining our own XML Message
lt?xml version"1.0" encoding"UTF-8"?gt lt!-- Trade
information --gt ltTradegt ltInstrument symbol"IBM"
securityType"Stock"/gt ltQuantitygt100lt/Quantitygt
ltTradePricegt80.00lt/TradePricegt ltTradeDategt2002013
0lt/TradeDategt ltSidesgt ltSide type"buy"gt ltCus
tomergtJohn Doelt/Customergt ltAccountgt102435lt/Acco
untgt ltOrderIDgtABC-1453-20020130lt/OrderIDgt lt/S
idegt ltSide type"sell"gt ltFirmgtSSBlt/Firmgt lt/
Sidegt lt/Sidesgt lt/Tradegt
Is this Well Formed???
NEW
40
Defining our own markup languages

• We said earlier that XML is a meta markup
  language
• XML is used to create domain specific markup
  languages
• How do we agree upon a dialect and then share
  this with others?
• How do we know if an XML message complies with
  our XML dialect (a ML if you will) ?
• There has to be
• some mechanism we can use to describe our
  particular markup language (be it FIXML, FpML,
  JimML, EdML, MathML, AgXML, )
• some way to share this description of our ML
• some way automate the process of making sure an
  incoming XML message is a valid ML message

Good News There Is!!!!
41
Describing XML Messages

• Document Type Definitions (DTDs)
• XML Schema

The Bad News is there is more than one way!
42
XML The Crash Course, Part 2

• Defining and validating XML Messages

43
XML Crash Course Part 2

• Describing XML Documents
• Validation
• Document Type Definitions
• Elements
• Attributes
• Internal
• External
• Using Internal and External together
• Namespaces
• XML Schema
• XML Documents as a tree
• XPath
• XLink
• XPointer

NEW
44
Describing XML Messages

• Document Type Definitions (DTDs)
• Provided with the original definition of SGML as
  defined by Goldfarb
• Think of DTD statements as control statements for
  defining XML documents
• DTD statements are not really XML statements
• Cannot use XML tools to manipulate DTD statements
• Some consider the DTD statements as a separate
  language
• In practice it is a separate language though it
  is a fundamental part of XML
• XML Schema
• An XML based language for defining XML documents
• Permits manipulation of the schema using standard
  XML tools
• This is like defining the database schema in
  tables in a relational database
• A recursion if you will

Improved
45
Why add rules to our Trade XML?

• Allows us
• to document and communicate what we consider as a
  valid trade message
• to validate our own trade messages
• to validate trade messages we receive from others

NEW
46
Document Type Definitions

• DTDs are sets of rules that define the elements
  and attributes in any XML document
• Have their own syntax - kind of
• Why arent they required?

lt!ELEMENT name (PCDATA)gt lt!ATTLIST ElementName
Attrib-Name Datatype Defaultgt lt!ENTITY
EntityName textgt lt!NOTATION NameSystem
externalIDgt
47
DTD Building Blocks

• We previously discussed the following
• Elements
• Tags
• Attributes
• Entities
• Types of data in XML Documents
• PCDATA
• Parsed Character Data
• An XML Processor looks for other XML building
  blocks within the data
• CDATA
• Character Data
• An XML Processor does not look for other XML
  within the data

NEW
48
Defining Elements

• Defining an element that can contain any kind of
  data
• lt!ELEMENT name ANYgt
• Defining an empty element
• lt!ELEMENT name EMPTYgt
• Defining an element that has mixed content
• Choice
• lt!ELEMENT name PCDATA childElement(s) gt
• Defining an element that has only child elements
• Sequential order
• lt!ELEMENT name ( childElem1, childElem2,
  childElem3 )gt

49
Defining Child Elements

• Declaring one and only one child element
• lt!ELEMENT name ( child-name ) gt
• Declaring at least one child element, permitting
  multiple occurrences
• lt!ELEMENT name ( child-name ) gt
• Declaring zero or to one occurrences of a child
  element
• lt!ELEMENT name ( child-name? ) gt
• Declaring zero or to one occurrences of the same
  child element
• lt!ELEMENT name ( child-name ) gt
• Declaring Options Elements
• lt!ELEMENT name ( childElem1 childElem2
  childElem3 )gt

1..1
1..n
? 0..1
0..n
NEW
50
Defining Child Elements

• Permitting different child elements (either/or)
• lt!ELEMENT name ( childElem1 childElem2
  childElem3 )gt
• Permitting a mix of child elements
• lt!ELEMENT name PCDATA ( childElem1
  childElem2 childElem3 )gt
• Defining an ordered sequence
• lt!ELEMENT name ( childElem1 , childElem2 ,
  childElem3 )gt

or
, sequence
NEW
51
Working with Groups of Elements

• You can apply the cardinality rules to groups of
  elements
• lt!ELEMENT name ( childElem1 , childElem2 ,
  childElem3 )? gt

NEW
52
Defining Attributes - Syntax

• Defining Attributes for Elements
• lt!ATTLIST element-name attribute-name
  attribute-datatype default-value
• element-name attribute-name attribute-datatype
  default-value
• ...
• gt

NEW
53
Attribute Datatypes

• Attribute Datatypes (or just types)
• CDATA
• Character Data
• an enumerated list using the
• Values separated by the (vertical bars)
• lt!ATTLIST Instrument SecurityType
  (StockBondFutureOption) Stockgt
• Other types (we wont talk about today)
• ID
• IDREF
• IDREFS
• ENTITY
• ENTITIES
• NMTOKEN
• NMTOKENS
• NOTATION

NEW
54
Attribute Default Values

• Attribute Default Values
• REQUIRED
• Attribute must be included in the Element
• IMPLIED
• The attribute is optional (does not have to be
  supplied)
• FIXED default-value
• The attribute is optional - if it is not supplied
  use the default value provided
• default-value
• For enumerated lists - the default if the
  attribute is not specified

NEW
55
Defining Attributes

• Defining an element that can contain any kind of
  data
• lt!ATTLIST element-name attribute-name
  attribute-datatype default-value gt
• ltPosQty Lng"635" Sht"1" Typ"SOD"/gt

NEW
56
Defining Attributes

• Defining an element that can contain any kind of
  data
• lt!ATTLIST element-name attribute-name
  attribute-datatype default-value gt
• ltPosQty Lng"635" Sht"1" Typ"SOD"/gt

NEW
57
Proposed FIX 4.4 Positions Report in TO-FIXML
lt?xml version"1.0" encoding"UTF-8"?gt ltFirmPortfo
liogt ltAppMsggt ltPosRpt
BusDt"2002-11-13" PrStlPx"72.925" ReqID"1RFP"
ReqTyp"T" RptID"1" StlPx"73.10"
StlPxTyp"FINAL"gt ltStlSes
ID"EOD"/gt ltPartiesgt ltPty ID"CME"
R"21"/gt ltPty ID"560" R"4"/gt ltPty ID"560"
R"27" Typ"1"/gt lt/Partiesgt ltInst CFI"FXXPSX"
CVF"400" Ccy"USD" Exch"CME" ID"48"
MatDt"2002-12" StlDt"2002-12-31"/gt ltPositionsgt
ltPosQty Lng"635" Sht"1" Typ"SOD"/gt
ltPosQty Lng"601" Sht"1" Typ"EOD"/gt
ltPosQty Lng"3" Sht"37" Typ"ALC"/gt
ltPosQty Lng"68" Sht"0" Typ"IAS"/gt
ltPosQty Lng"1" Sht"1" Typ"IES"/gt
lt/Positionsgt ltAmountsgt ltPosAmt
Amt"45770.00" Typ"FMTM"/gt ltPosAmt
Amt"44380.00" Typ"SMTM"/gt lt/Amountsgt
lt/PosRptgt lt/AppMsggt
lt/FirmPortfoliogt
NEW
58
Defining DTD statements for TO-FIXML

• lt?xml version"1.0" encoding"UTF-8"?gt
• ltFirmPortfoliogt
• ltAppMsggt
• ltPosRpt BusDt"2002-11-13"
  PrStlPx"72.925" ReqID"1RFP" ReqTyp"T"
  RptID"1" StlPx"73.10" StlPxTyp"FINAL"gt
• ltStlSes ID"EOD"/gt
• ltPartiesgt
• ltPty ID"CME" R"21"/gt
• ltPty ID"560" R"4"/gt
• ltPty ID"560" R"27" Typ"1"/gt
• lt/Partiesgt
• ltInst CFI"FXXPSX" CVF"400" Ccy"USD"
  Exch"CME" ID"48" MatDt"2002-12"
  StlDt"2002-12-31"/gt
• ltPositionsgt
• ltPosQty Lng"635" Sht"1" Typ"SOD"/gt
• ltPosQty Lng"601" Sht"1" Typ"EOD"/gt
• ltPosQty Lng"3" Sht"37" Typ"ALC"/gt
• ltPosQty Lng"68" Sht"0" Typ"IAS"/gt
• ltPosQty Lng"1" Sht"1" Typ"IES"/gt
• lt/Positionsgt
• ltAmountsgt

NEW
59
Adding an internal definition to our XML
lt?xml version"1.0" encoding"UTF-8"?gt lt!-- Trade
information --gt lt!DOCTYPE Trade lt!ELEMENT
Account (PCDATA)gt lt!ELEMENT Customer
(PCDATA)gt lt!ELEMENT Firm (PCDATA)gt lt!ELEMENT
Instrument EMPTYgt lt!ATTLIST Instrument symbol
CDATA REQUIRED securityType CDATA
REQUIRED gt lt!ELEMENT OrderID (PCDATA)gt lt!ELEMENT
Quantity (PCDATA)gt lt!ELEMENT Side ( (Customer
Account OrderID) Firm)gt lt!ATTLIST
Side type (buy sell) REQUIRED gt lt!ELEMENT
Sides (Side)gt lt!ELEMENT Trade (PCDATA
Instrument Quantity Sides TradeDate
TradePrice)gt lt!ELEMENT TradeDate
(PCDATA)gt lt!ELEMENT TradePrice
(PCDATA)gt gt ltTradegt rest of TRADE xml
omitted on this slide lt /Tradegt
NEW
60
Using an External DTD
lt?xml version"1.0" encoding"UTF-8"?gt lt!-- Trade
information --gt lt!DOCTYPE Trade SYSTEM
"D\home\jim\FIX\FIA_XML_Workshop\FIXML_43\trade.d
td"gt ltTradegt ltInstrument symbol"IBM"
securityType"Stock"/gt ltQuantitygt100lt/Quantitygt
ltTradePricegt80.00lt/TradePricegt ltTradeDategt2002013
0lt/TradeDategt ltSidesgt ltSide type"buy"gt ltCus
tomergtJohn Doelt/Customergt ltAccountgt102435lt/Acco
untgt ltOrderIDgtABC-1453-20020130lt/OrderIDgt lt/S
idegt ltSide type"sell"gt ltFirmgtSSBlt/Firmgt lt/
Sidegt lt/Sidesgt lt/Tradegt
NEW
61
Our External Trade DTD File
lt?xml version"1.0" encoding"UTF-8"?gt lt!--
edited with XMLSPY v5 rel. 2 U (http//www.xmlspy.
com) by James Northey --gt lt!--DTD generated by
XMLSPY v5 rel. 2 U (http//www.xmlspy.com)--gt lt!EL
EMENT Account (PCDATA)gt lt!ELEMENT Customer
(PCDATA)gt lt!ELEMENT Firm (PCDATA)gt lt!ELEMENT
Instrument EMPTYgt lt!ATTLIST Instrument symbol
CDATA REQUIRED securityType CDATA
REQUIRED gt lt!ELEMENT OrderID (PCDATA)gt lt!ELEMENT
Quantity (PCDATA)gt lt!ELEMENT Side ((Customer
Account OrderID) Firm)gt lt!ATTLIST Side type
(buy sell) REQUIRED gt lt!ELEMENT Sides
(Side)gt lt!ELEMENT Trade (PCDATA Instrument
Quantity Sides TradeDate TradePrice)gt lt!ELE
MENT TradeDate (PCDATA)gt lt!ELEMENT TradePrice
(PCDATA)gt
62
XML Namespaces

• Sometimes you need to reuse other definitions
• Sometimes you have naming conflicts between
  different syntax

NEW
63
XML Schema

• Using XML to define XML messages

NEW
64
Think of an XML Document as a Tree of Information
65
XML document as a tree of information

• Operating System File Systems
• File Systems are organized in a tree like
  structure
• Files Systems contain directories that contain
  files and other directories (sub directories)
• The main directory is called the root directory
• You can traverse the file system directory tree
  using commands, such as cd (change directory)
• There is the concept of the current working
  directory - where you are in the file system tree
  structure

• XML Documents
• XML documents are organized into a tree like
  structure
• XML documents contain elements that contain
  attributes and other elements (nested elements)
• The main element is called the root element
• You can traverse the XML document element tree
  using your own programs or XPATH commands
• There is a concept of the current node - the
  point where you are in the XML document tree
  structure

66
There is a name for this XML tree inside a program

• The Document Object Model (DOM) is a way to
  represent an XML message within a program
• The Document Object Model is organized as a tree
  of XML elements starting at the root element
• You can walk the tree using the DOM application
  programming interface

67
XPath

• Trees can be climbed (traversed)
• Syntax for searching and traversing an XML
  document tree
• Sort of like wild cards or regular expressions
• Instead of applying to a text file - applied to a
  tree
• Thinking about Paths
• There is a path to take
• Here is the path taken

68
Internet Resources

• W3Schools.com
• http//www.w3schools.com
• World Wide Web Consortium
• Definitions of everything we have talked about
• http//www.w3c.org
• The Cover Pages by Robin Cover
• http//xml.coverpages.org/
• Open OASIS - Supporting XML based industry
  standards
• http//www.oasis-open.org/

Improved
69
XML The Benefits

• Oren Miller
• Senior Director of Software Development,
  Thoughtworks, Inc.

70
Extensible Stylesheet Language Transformations
(XSLT)

• Used to transform XML Content (And IS XML)
• Rule Based Language (Not Sequential)
• Declarative Query Syntax (Xpath), like SQL
• Templates
• ltxsltemplate match/gt
• ltxsltemplate name/gt
• Data Retrieval
• ltxslvalue-of select/gt
• Iteration
• ltxslfor-each select/gt
• Decisions
• ltxslif test/gt
• ltxslchoosegt, ltxslwhengt
• Variables
• ltxslvariablegt, ltxslparamgt

71
Position Report to be Transform to an SQL Update
lt?xml version"1.0" encoding"UTF-8"?gt ltFirmPortfo
liogt ltAppMsggt ltPosRpt
BusDt"2002-11-13" PrStlPx"72.925" ReqID"1RFP"
ReqTyp"T" RptID"1" StlPx"73.10"
StlPxTyp"FINAL"gt ltStlSes
ID"EOD"/gt ltPartiesgt ltPty ID"CME"
R"21"/gt ltPty ID"560" R"4"/gt ltPty ID"560"
R"27" Typ"1"/gt lt/Partiesgt ltInst CFI"FXXPSX"
CVF"400" Ccy"USD" Exch"CME" ID"48"
MatDt"2002-12" StlDt"2002-12-31"/gt ltPositionsgt
ltPosQty Lng"635" Sht"1" Typ"SOD"/gt
ltPosQty Lng"601" Sht"1" Typ"EOD"/gt
ltPosQty Lng"3" Sht"37" Typ"ALC"/gt
ltPosQty Lng"68" Sht"0" Typ"IAS"/gt
ltPosQty Lng"1" Sht"1" Typ"IES"/gt
lt/Positionsgt ltAmountsgt ltPosAmt
Amt"45770.00" Typ"FMTM"/gt ltPosAmt
Amt"44380.00" Typ"SMTM"/gt lt/Amountsgt
lt/PosRptgt lt/AppMsggt
lt/FirmPortfoliogt
72
Creating an extract of positions only
Contains position and trade record XML messages
Position Report Trade Capture FIXML File
Selects Position Reports from the file with
position reports and trade detail
extposrepts.xsl
Positions XML File
Improved
73
Selecting only Position Reports

• The following XSLT statement is used to select
  only the Position reports from the file
  containing Position Report and Trade Capture
  messages

lt!-- only process application messages that are
position reports --gt ltxsltemplate
match"AppMsg/node()name()'PosRpt'"gt
Improved
74
Creating a text file
Contains position and trade record XML messages
Position Report Trade Capture FIXML File
Selects the position reports and and creates a
comma delimited text file
fixml2text.xsl
Text file containing the position information
Positions text file
Improved
75
Creating a database insert script
Contains position and trade record XML messages
Position Report Trade Capture FIXML File
Selects the position reports and creates an SQL
script to insert positions into a database
fixmltosql.xsl
SQL script created by the XSLT
SQL Script
Positions Database
Improved
76
Position Report Database Schema
Position Report
Parties
Positions
Amounts
77
Accessing the parties, positions, and amounts

• The following XSLT fragment writes the Parties,
  positions, and amounts into separate tables
• Notice that a subroutine or template is used,
  sql-insert-collection

ltxslfor-each select"node()"gt lt!-- insert
collections (eg. Parties, Positions, Amounts)
--gt ltxslif test"count(node())gt0 and
name()!'Inst'"gt ltxslcall-template
name"sql-insert-collection"/gt lt/xslifgt
lt/xslfor-eachgt lt/xsltemplategt
78
The sql-insert-collection Template

• This template is used to iterate through multiple
  elements (such as parties or positions) and
  create insert statements
• Notice that it calls two other templates,
  sql-insert-fields and sql-insert-values

lt!-- insert statement for a position report
collection --gt ltxsltemplate name"sql-insert-coll
ection"gt ltxslfor-each select"node()"gt
INSERT INTO ltxslvalue-of select"name(..)"/gt
( RptID, ltxslcall-template
name"sql-insert-fields"/gt ) VALUES
( quotltxslvalue-of select"../../_at_RptID"/
gtquot, ltxslcall-template
name"sql-insert-values"/gt )
lt/xslfor-eachgt lt/xsltemplategt
79
Templates that are used in this example

• Templates created to iterate and create the
  fields and the values for the table insert

lt!-- field names for insert --gt ltxsltemplate
name"sql-insert-fields"gt ltxslfor-each
select"_at_"gt ltxslvalue-of select"name()"/gt
ltxslcall-template name"comma"/gt
lt/xslfor-eachgt lt/xsltemplategt
Notice each of the templates on the left use the
comma template...
lt!-- will not insert comma after last element
--gt ltxsltemplate name"comma"gt ltxslif
test"not(position()last())"gt,lt/xslifgt lt/xsltem
plategt
lt!-- values for insert --gt ltxsltemplate
name"sql-insert-values"gt ltxslfor-each
select"_at_"gt ltxslvalue-of select"."/gt
ltxslcall-template name"comma"/gt
lt/xslfor-eachgt lt/xsltemplategt
80
Accessing XML Messages from an application program

• Matt Simpson
• Associate Director, Clearing IT, Chicago
  Mercantile Exchange, Inc.

81
XML Integration Assumptions

• Java is your base development language
• You can run a Java Virtual Machine (JVM) on your
  platform
• Your Operating System can be Sun/Solaris,
  HP-Unix, OS390-based Unix, Microsoft OSs
  including NT, XP, and Windows, and various
  flavors of Linux
• Your development is J2EE-oriented and can
  leverage XML APIs
• App Servers are not necessary, but a number can
  be used including Weblogic, Websphere, Apache
  Tomcat, and others
• There are others products and implementations
  which will not be addressed in this overview.

82
Principles of the Java XML APIs

• J2EE XML APIs - engineered by Sun and accepted
  as a standard by much of the industry are a
  good starting point for any XML-oriented
  application
• Adhere to industry standards regarding XML and
  thus ensure interoperability
• Broad functionality allows choice of application
  architectures
• Flexibility within a well-defined framework
  ensures that all implementations will deliver
  standard functionality.

83
What makes XML an Attractive Technology

• Extensibility tags can be added as needed
• Portability given a DTD, a parser will know the
  structure and type of content for any xml
  document
• Loosely coupled to Business Processes
• Human readable allows business users to
  interpret data
• System independent way of representing data
• New Java APIs making XML easier to use
• Validation of documents can be enforced or not,
  depending on the need

84
JAXB Java API for XML Binding

• Overview
• JAXB is a new standard being developed via Suns
  Java Community which provides a way to map XML
  documents to Java objects.
• Suns implementation generates Java classes
  representing elements in a DTD. These classes
  contain XML parsing logic.
• JAXB is essentially a bridge between XML and
  Java. It allows creation of Java objects at the
  same level as the XML.
• Maps XML to Java data objects
• Acts as a code-generator using a DTD (not a
  schema)
• Uses a DTD to bind to a set of generated
  classes
• The binding schema is an XML-based binding
  language
• Classes are generated which maps your XML to
  internal data objects

85
JAXB Java API for XML Binding
86
JAXB Java API for XML Binding

• Disadvantages of JAXB
• The evolving FIXML standard may require
  generating new Java classes each time the DTD
  changes.
• In order to avoid coding changes to the business
  logic an additional abstraction is required which
  complicates the overall architecture.
• Youre Stuck with the object that is generated.
• Classes containing business logic are more likely
  to change as XML-mapping classes and the DTD
  change.
• May not address some of the mapping issues needed
  for complex xml-object mappings.
• Causes domain/data objects to contain XML parsing
  logic. In order to avoid coding changes to the
  business logic an additional abstraction is
  required which complicates the overall
  architecture.
• May introduce additional OO complexity.
• Evaluated, but not used by CME. Would have
  caused the CMEs switch to attributes to be more
  cumbersome.

87
JAXP Java API for XML Processing

• Overview
• A J2EE API that provides access to the XML
  parsing techniques SAX and DOM.
• Has a Pluggabability-Player feature allows any
  XML-compliant parser to be used.
• Implementation Independent meaning any API
  compliant parser can be used with JAXP
• The prominent implementations are provided by
  Crimson and Apache Xerces

88
JAXP Java API for XML Processing

• Both implementations provide SAX, DOM, XSLT APIs
  - SAX and DOM being parsers
• Adds methods that allows generated code to be
  parser-independent
• Xerces has its own implementation of SAX and DOM
  used by JAXP
• For reconstruction, we ended up bypassing the
  JAXP interfaces and using the Xerces interfaces
  directly.
• Disadvantages
• JAXP provides a way to reconstruct an XML
  document using DOM
• but serialization to a string requires using an
  XSL transformation which is very slow.

89
JAXP Java API for XML Processing
90
The SAX Parser

• Overview
• SAX (Simple API for XML) is an event-based parser
  which reads XML in a stream and each time it
  recognizes a tag, extracts the data.
• SAX is most effective when only a part of a
  document needs to be parsed.
• As SAX parses, the data is extracted from the XML
  string and made available for mapping.
• Code is required to map SAX object to internal
  Java data object.
• Disadvantages
• More complex requires creating your own
  tree-like structure.
• Does not provide support for Reconstruction of
  documents.

91
SAX Sample

• The sample code belows show the SAX
  startElement method and its implementation
  which prints out the tag name
• public void startElement (String _uri, String
  _localName, String _prefix, Attributes attrs)
• throws SAXException
• if (_localName.equalsIgnoreCase("AppMsg"))
• System.out.println("ltAppMsggt tag found!")
• else if (_localName.equalsIgnoreCase("PosReq"))
• System.out.println("ltPosReqgt tag found!")
• ...
• This method is called by SAX when it sees the
  body of the tag.
• public void characters (char buf , int offset,
  int len)
• throws SAXException
• String str new String(buf, offset,
  len)
• System.out.println(str)

92
DOM Parsing

• DOM (Document Object Model) is a parser which
  allows random access to particular pieces of data
  AFTER the entire document has been loaded into
  memory
• Once in memory, the document can be modified,
  something which SAX does not support.
• DOM provides a simple way to construct a new XML
  document in memory and add elements to it while
  traversing the Java domain objects.
• Disadvantages (vs. SAX)
• In general, DOM is less efficient since it takes
  more time to load and search memory
• Does not provide a parser independent way to
  serialize an XML document into a String meaning
  XSL must be used

93
DOM Sample
The sample code below shows how DOM references an
XML document in memory. In this example, an
element called PosReq is located and the
corresponding data is subsequently extracted and
printed. DocumentBuilderFactory factory
DocumentBuilderFactory.newInstance()
DocumentBuilder builder factory.newDocumentBuild
er() Document document
builder.parse(new ByteArrayInputStream(xml.getByte
s())) NodeList list document.getElement
sByTagName("PosReq") for(int i0
iltlist.getLength()i)
System.out.println(list.item(i))
94
The Apache Digester Model

• Overview
• Provides an easily configurable framework for
  mapping XML messages to Java objects using an XML
  parser
• Conforms to the SAX 2.0 specification
• The Digester component leverages the strengths of
  the SAX event model for parsing XML which include
  speed and efficient memory usage
• Used to load configuration data
• Does not build mapping classes like JAXB
• Uses a pattern to perform mapping which can be
  expressed in a java class or in a .properties or
  config file
• The Digester hides its complexity behind an easy
  to use interface
• Disadvantages
• Significantly slower than a custom solution due
  to complexity

95
The Apache Digester Model
96
A Customized Approach

• Overview
• The custom solution uses the Apache Xerces parser
  which provides support for JAXP, DOM, and SAX
  APIs.
• the JAXP interfaces were bypassed for
  serialization and the Xerces interface was called
  directly.
• Why???
• the SAX API provides fast and memory efficient
  event driven parsing of XML documents. It is the
  most rapid way to put XML string into a Java
  object.
• The incoming messages are first mapped to a tree
  of lightweight objects representing the elements
  in the document.
• This representation uses fewer objects and
  therefore less memory than a DOM representation.
  
• The tree is then traversed and custom code is
  used to map each of the elements in the tree to a
  corresponding Java domain object.
• Apache Xerces SAX parser implementation is used
  under the covers and is masked from the
  developer.

97
A Customized Approach
98
A Customized Approach

• Advantages
• The FIXML Translator implementation encapsulates
  all the XML document parsing and construction
  logic behind a simple interface.
• It isolates the rest of the Position Services
  application from changes to the evolving FIXML
  standard.
• The custom code used for the implementation
  leverages standard APIs familiar to Java
  developers and can be quickly and easily updated
  when changes to the FIXML standard are required.

99
XML Reconstruction

• DOM is used to map Java domain objects to
  outgoing FIXML messages
• The DOM API is used because the SAX API does not
  provide a way to construct an XML document
• The DOM API provides a simple way to construct a
  new XML document in memory and add elements
• After the XML document is constructed, it is
  serialized into a String using a Xerces parser
  specific API.
• DOM does not provide a parser independent way to
  serialize an XML document into a String, so JAXP
  provides a way to do this via XSLT.
• XSL Transformation API is slow
• Reconstruction a customized approach
• DOM used to build doc in memory
• Xerces specific API used to construct outbound
  string
• XMLSerializer class used to for this purpose
• JAXP is bypassed for serialization
• Sun is aware of this shortcoming and will provide
  better support for message reconstruction in the
  next release

100
Conclusion

• JAXB DTD code generation solution for XML to
  Object mapping.
• Digester Pattern-based solution for XML to
  Object mapping
• JAXP Complete standard API for XML handling
  includes SAX and DOM
• SAX Event-based parsing. Fast and efficient.
  Does not support Reconstruction
• DOM Loads entire XML document to memory tree.
  Supports Reconstruction

101
Implementing XML Notes from the field

• David Li
• Chief Architect, New York Mercantile Exchange

102
XML Practice in Nymex

• Universal Trading Message - UTM

103
Goal

• Create internal messaging protocol for loosely
  coupled applications.
• Messaging (SmartSocket) pub/sub queue
• Legacy, J2EE, stand alone, Java, C

104
Resolve Task

• Define comprehensive messaging schema for
  application data exchange.
• Started using Fix superset
• Originally used tag definitions based on Fix
  protocol in the form of lttaggt value lttaggt
• Used blocks similar to Fix to group relevant
  data elements
• Schema in one file

105
Issues

• This is problematic for the following reasons
• Not user readable
• Large file size for even small sets of data
  creates difficulty (12k)
• Schema management
• Schema elements are not reusable
• Unable to successfully use it with data binding
  tools

106
How we resolved the issues

• Changed tags to user readable tags
• Changed data to lttag elementgt ltsubtaggt format so
  that only repeated data gets its own tag.
  Reduced the size and simplified data binding
  process. (15k)
• Broke schema down to block level, which allowed
  for reusability and easy management

107
Data Binding Tools

• Based on the schema, classes get generated
• To maintain object library held to maintain only
  schema, without any programming
• Excellent performance castor uses JAX parser to
  set data fields

108
Instant validation

• by setting fields to XML on UML generated object
  libraries, perform instant validation
• Used in common code repository for different
  application, enforces versioning and data
  consistency throughout the enterprise
• Link to JAXB, Castor, Talarian, Clearcase

109
Conclusion

• Recommendations and highlights
• Make sure schema is extendable
• Data binding is in use by all applications in
  enterprise
• Effective use of code repository to distribute
  latest data objects and schema throughout the
  enterprise

110
Putting XML to Work Today

• Matt Simpson
• Associate Director, Clearing IT, Chicago
  Mercantile Exchange, Inc.

111
Objectives of Post-Trade APIs

• Extend Clearing beyond the traditional screen and
  browser based offering by providing a
  message-based interface into a core set of
  Clearing Services.
• Actively support and advance a standard that will
  achieve a Build once, interface many times
  approach for the firms.
• Allow firms to connect back-office systems to CME
  Clearing in order to seamlessly integrate
  transaction processing between CME Clearing and
  firms.
• Eliminate/reduce redundant maintenance. Firms
  will no longer need to perform maintenance in
  their systems and again in CME Clearing Systems.
• Promote Straight-thru-processing to reduce the
  risk of exposure of the CME and firms, and to
  allow greater financial transparency.
• Provide an open systems architecture that will
  host firm access to CME Clearing and allow firms
  to interface with the APIs via MQSeries

112
XML for STP
113
The Post-Trade APIs

• 1st Quarter 2003 Deliverable
• Exercise Notice
• Abandonment Notice
• Position Adjustment
• Final Position Instruction (PCS)
• Margin Disposition
• Request for Position
• This intent of this service is to replace and
  supercede the Machine Readable Trade Register
  which is a limited-format batch file.
• The Position Request will return varying levels
  of detail based on the nature of the request.
• And More are on the way!

114
Architectural Goals

• The Post-trade Architecture adheres to the
  following design goals
• Decouple FIX-specific dependencies from the
  underlying business logic of the Post-Trade API
  System.
• Decouple Message Delivery dependencies from the
  underlying business logic of the Post-Trade API
  System and from the FIXML format itself.
• Ensure that the Post-Trade API System has a
  well-defined transaction context for each
  request/response.
• Support additional FIXML messages with
  close-to-zero integration effort.
• Enforce controlled exception handling.
• Support processing of messages that may be
  initiated via non-message-based requests, eg User
  Interface Requests

115
High-level Architecture
116
Internal Architecture
117
Architectural Components

• There are three high-level control layers for the
  iCPS architecture.
• RD Mediator (for communication)
• FIX Command Session (translation, delegated
  execution)
• Command Session (execution)

118
XML Class Structure
119
Principals of Optimizing FIXML

• Use meaningful abbreviations for element and
  attribute names wherever possible. Use standard
  abbreviations for common words (ie. Price Px,
  Currency Ccy).
• Identify the messages used in the application and
  create top level elements to represent them. For
  position services, these elements are the
  position maintenance request (PosMaintReq),
  position maintenance report (PosMaintRpt),
  position request (PosReq), position request
  acknowledgement (PosReqAck), position report
  (PosRpt), and trade capture report (TrdCapRpt).
• Identify data items that can be grouped together
  to describe a logical object and create an
  element to represent the object. For example, an
  account ID and account type can be grouped
  together as an account element with supporting
  attributes.
• Reuse elements to represent common logical
  objects which are parts of other objects rather
  than creating new elements. For example, a party
  is an object that is part of a position
  maintenance request, position request, and trade
  capture report side and can also be nested within
  a position quantity.
• Reuse attributes across multiple objects
• Identify elements that can be repeated and create
  a collection element to contain the repeated
  elements. For example, multiple parties are
  needed on a message and a collection element
  called Parties was created to contain multiple
  Pty elements.

120
FIXML Message Components

• Parties Block
• 1. The purpose of the Parties Block is to provide
  an efficient, standard way of expressing Firm and
  Account information in API Messages. The Parties
  Block consists of the following elements
• Party Role, Party ID, Party Sub ID, and Party ID
  Source.
• Party Role is a static number used to express the
  type of party, for example Clearing Organization,
  Clearing Firm, etc.
• Party