XFB

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XFB

• There's a fine line between genius and insanity.
  I have erased this line.Oscar Levant

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Origins of XFB

• XFB (Extended Fusebox) grew out of a desire to
  tip the scale of project success.
• XFB combines technical innovations (XFAs, query
  sims, nested circuits, nested layouts, integrated
  security, etc.) with project management features.

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70 Failure
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Time Expended
Nike Method
Design
Testing
Delivery
Coding
Architecture
Requirements
www.halhelms.com
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Time Expended
Extended Fusebox Method
Coding
Testing
Delivery
Architecture
Requirements/Design
www.halhelms.com
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Main Points of XFB

• Project Management
• wireframes
• prototypes
• devnotes
• Technical
• xfas
• fusedocs
• nested circuits
• nested layouts
• query sims
• security
• assertions

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Wireframe
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Wireframe

• Wireframes provide a "booster rocket" to help us
  escape the gravitational pull of our prejudices
  and assumptions about what clients want.

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Wireframe

• The wireframe is a skeleton-model of an
  application.
• It is meant to help clients and developers
  discuss what an application should do.

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Wireframe
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Wireframe
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Wireframe

• Download available at www.bjork.net

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Prototype w/DevNotes
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Why a prototype?

• "Requirements gathering" doesn't work
• The Musee d'Orsay in Paris wants to hire you to
  reproduce a famous painting Arrangement in Black
  and Grey No. 1
• Specification "The work shall be oil on canvas,
  56-1/4" x 63-1/4"..."

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Is this what they want?
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Is this what they want?
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Is this what they want?
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Is this what they want?
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Is this what they want?
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THIS is what they want!
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Why the prototype?

• Clients can only tell you what they want after
  they see it

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What is the prototype?
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Leaving no "wiggle room"
The prototype
The deployed application
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An iterative process

• The wireframe forms the basis for the first cut
  of the prototype
• Prototypes have minimal codeand are often best
  handled by non-programmers
• The prototype is refined through interaction with
  client and developer using DevNotes

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What is DevNotes?

• DevNotes is a simple, threaded message system
  that sits below each individual prototype page.
• All issues related to the application are
  recorded as DevNotes

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What are DevNotes used for?

• Client direction "Move the buttons to the
  left/Make the blue a little more like cornflower
  and less like slate"
• Developer questions "Where will the product
  information come from?/Is there an existing
  database or file with authorized users?"
• Client answers "I think the IT people have a
  spreadsheet or something with users."

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What are DevNotes used for?

• Developer self-notes "Use JavaScript for client
  processing of this procedure"

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Prototype freeze

• We are done with the prototype when both client
  and developer are confident that
• all questions regarding functionality have been
  resolved
• all content has been received from client
• graphical interface/look and feel has been
  approved
• any changes occurring after this point will
  either become a new release or will be
  exorbitantly expensive

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Fusebox architecture
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Unplanned program flow
Module F
Module E
Module B
Module C
Module A
Module D
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Architected program flow
Module E
Module F
Module C
Module A
Module B
Module D
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A Fusebox request
validateLogin
the fuseaction
loginUser
Fusebox
qryValidateLogin.cfm
validateLogin
actValidateLogin.cfm
newUser
fuses
the fusebox
fuseactions
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Fuses always make requests of the fusebox
ltform actionindex.cfm methodpostgt ltinput
typehidden namefuseaction valuevali
dateUsergt ltinput typetext nameusernamegt lt
input typepassword namepasswordgt ltinput
typesubmitgt lt/formgt
Fusebox
a fuse
the fusebox
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The fusebox copies all URL and form variables
into attributes scope
ltcf_FormURL2Attributesgt
url.productID 1027 form.lastName Helms
attributes.productID 1027 attributes.lastName
Helms
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The fusebox
ltcfswitch expression attributes.fuseactiongt
ltcfcase valueloginUsergt ltcfinclude
templatedspLoginUser.cfmgt lt/cfcasegt ltcfcas
e valuevalidateLogingt ltcfinclude
templateqryValidateLogin.cfmgt ltcfinclude
templateactValidateLogin.cfmgt lt/cfcasegt lt/cfs
witchgt
The fusebox
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Fuseactions

• The fuseaction is the motivating force in an
  application.
• Suggestion use name is form of verbNounPhrase
  such as
• addItemToCart
• getUserInfo
• showProductInfo

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The fusebox
ltcfswitch expression attributes.fuseactiongt
ltcfcase valuedoSomethinggt ltcfinclude
templateaFuse.cfmgt lt/cfcasegt . ltcfcase
valuedoSomethingElsegt ltcfmodule
templateanotherFuse.cfmgt lt/cfcasegt lt/cfswitch
gt
The fusebox
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Including a fuse
The fuseaction
doSomething
ltcfswitch expression attributes.fuseactiongt
ltcfcase valuedoSomethinggt ltcfinclude
templateaFuse.cfmgt lt/cfcasegt . ltcfcase
valuedoSomethingElsegt ltcfmodule
templateanotherFuse.cfmgt lt/cfcasegt lt/cfswitch
gt
yetAnotherFuse.cfm
The fuses
The fusebox
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Nested circuits
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Benefits of nested circuits

• More and easier code reuse
• Independent, concurrent development of code
  modules
• Descendant modules inherit variables from parents
• Variables from parents are inherited by children
• Layout files can be nested
• Exceptions bubble upwards

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XFB nested circuits
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Conflicting circuit names
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Resolving circuit naming conflicts

• Create a Circuits.cfm file
• Alias name conflicts

bpcf/completed/circuits.cfm
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FB3 nested circuits

• Fusebox 2 worked with the concept of a federation
  of circuits,each having to know of the existence
  of each other
• Fusebox 3 works with the concept of
  interchangeable circuits that can be reused in
  different applications

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Inheritance
ltcfset dsn "OurApplication"gt
ltcfquery datasourcedsngt
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Bubbling exceptions

• Lets architect determine where certain exception
  types will be handled
• Lets coder write fuses without worrying about
  handling certain classes of exceptions

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Example Bubbling exceptions
lt!-- index.cfm --gt ltcftrygt ltcfcatch
typeUserAlertgt ltscriptgt alert( lt/scriptgt
lt/cfcatchgt lt/cftrygt
lt!-- index.cfm --gt
lt!-- aFuse.cfm --gt ltcftrygt ltcfinclude
templatemyPage.cfmgt ltcfcatchgt
ltcf_LogException messagecfcatch.messagegt lt
cfthrow typeUserAlertgt lt/cfcatchgt lt/cftrygt
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XFAs
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XFAs

• A typical Fusebox 2 page has fuseactions
  hardcoded in place.
• Examples
• ltform action"index.cfm?fuseactionupdateProductIn
  fo"gt
• lta href"index.cfm?fuseactionshowUserMenu"gt
• ltcflocation url"index.cfm?fuseactionshowMainPage
  "gt

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XFAs

• XFAs are variables that lets fuseactions be
  resolved at run time
• Examples
• ltform action"index.cfm?fuseactionXFA.submitForm
  "gt
• lta href"index.cfm?fuseactionXFA.next"gt
• ltcflocation url"index.cfm?fuseactionXFA.home"gt
  

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Identifying XFAs

• Mark up the prototype for any exit points any
  point at which the user or the system can make
  another fuseaction request

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Identifying XFAs
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Assigning values to XFAs

• Login XFA.submitForm ? validateUserLogin
• Login Validation XFA.success ? showMainCatalogPage
  
• Product Detail XFA.buyItem ? addItemToCart
• Cart XFA.adjust quantities ? adjustCartQuantities
• Cart XFA.removeItem ? removeItemFromCart
• Registered User XFA.editInfo ? editUserInfo
• Registered User XFA.saveInfoUpdate ? saveUser
• Admin Page XFA.newUser ? newUser

Identifying common nouns
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Identifying circuit and fuseaction
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Identifying needed fuses
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Fusedoc
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Fusedocs

• Provide documentation/PDL (program design
  language) for each fuse
• Tells coder what they need to know to write a
  fuse without knowledge of the application
• XML-based with DTD for validation

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Nested layouts
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ltcf_bodycontentgt tag

• Used to capture the output of code and save as a
  request-scoped variable
• Replaced in ColdFusion release 5 with
  ltcfsavecontentgt

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Example ltcf_bodycontentgt
ltcf_bodyContent name"me"gt ltcfset reverseColor
RandRange( 0, 1 )gt lttable border"2"gt lttrgt
lttdgtI am the left sidelt/tdgt lttdgtI am
the right sidelt/tdgt lt/trgt
lt/tablegt lt/cf_bodyContentgt ltcfinclude
template"layout.cfm"gt
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Example ltcf_bodycontentgt
ltcfoutputgt ltcfset thebg "white"gt ltcfset thefg
"black"gt ltcfif reversecolorgt ltcfset thebg
"black"gt ltcfset thefg "white"gt lt/cfifgt ltstylegt
td background-color thebg color thefg
lt/stylegt ltpgtrequest.melt/pgt lt/cfoutputgt
XMLSpy/FD4 validateLogin.cfm
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Nested layouts

• Nested circuits

Parent
Child
GrandChild
UKDAXF/SampleFB3/
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Post-processing decision making

• Because the child is returned to the parent as a
  variable (rather than simply output onto the
  screen), the parent can make decisions based on
  the results of the child's processing

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Implementing nested layouts

• Wrap the code in index.cfm with ltcfsavecontentgt
  (version 5) or ltcf_bodycontentgt (version 4) using
  the circuit's alias as the name of the variable
• (Illustration next)

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Implementing nested layouts

• ltcfsavecontent variable"Users"gt
•  
• ltcfinclude template"app_locals.cfm"gt
• lt!--- Peel off the first layer and determine
  whether to delegate the fuseaction. ---gt
• ltcfif ListLen( attributes.fuseaction, '.' ) GT 1gt
• ltcfinclude template"ListFirst(
  attributes.fuseaction, '.' )/index.cfm"gt
• ltcfelsegt
• lt!--- I'm going to get one (and only one)
  fuseaction at a time. Fuseactions
• correspond to methods or messages in OO
  languages. ---gt
• ltcfswitch expression "attributes.fuseaction
  "gt
• ltcfcase value"home"gt
• ltcfinclude template"UserInfo.cfm"gt
• lt/cfcasegt
• ltcfdefaultcasegt
• ltcfoutputgt
• I am the GetDirectoryFromPath(
  GetCurrentTemplatePath()) fusebox and I received
  a fuseaction called ltBgtltFONT COLOR"000066"gt
• "attributes.fuseaction"lt/FONTgtlt/Bgt that I don't
  have a handler for.
• lt/cfoutputgt
• lt/cfdefaultcasegt

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Implementing nested layouts

• If the child is to display something, call the
  layout file after the ltcfsavecontentgt tag
• ltcfinclude template"dsp_layout32a.cfm"gt

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Query sims
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Query sims

• Provides a simulated query to work with code
• Allows code architecture to be done before all
  database decisions have been finalized
• Provides instruction to SQL coders on what
  information is needed
• Lets architect determine data variable names

test/QSimSample
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Test harnesses

• Provides an easy-to-implement way of unit-testing
  fuses
• Should accompany all completed fuses

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Example test harness
ltcfset selfTestMe.cfmgt ltcfset XFA.submitForm
gt ltcfset XFA.cancelForm gt ltcfset
attributes.userID 101gt ltcfinclude
templatedspEditUser.cfmgt
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Proving the concept

• We all agree that your theory is crazy, but is
  it crazy enough?Niels Bohr

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