CFC Best Practices, Tips, and Tricks

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CFC Best Practices, Tips, and Tricks

• Raymond Camden
• jedimaster_at_mindseye.com

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Agenda

• Basic (but real!) Examples
• Best Practices (Suggestions)
• Tips and Tricks
• Resources

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Examples

• www.cflib.org
• CFCs serve as DB abstraction
• ResourceBundle CFC
• Localization Utility
• SimpleCMS
• Simple CMS based on CFCs

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Best Practices

• Control white space generated by CFC

ltcfcomponent displayName"Example"
output"false"gt ltcffunction name"test"
returnType"string" access"public"
output"false"gt ltcfreturn "This is a boring
function."gt lt/cffunctiongt
lt/cfcomponentgt
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Best Practices

• Supply Optional Attributes

ltcfcomponent displayName"Example2"
output"false"gt ltcffunction name"test"
returnType"string" access"public"
output"false" hint"This function
does blah using Foo's logic."gt ltcfargument
name"argone" type"string" required"true"gt
ltcfargument name"argtwo" type"numeric"
required"false" default"0"gt ltcfreturn
arguments.argone " with the number "
arguments.argtwogt lt/cffunctiongt
lt/cfcomponentgt
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Best Practices

• Use the VAR scope!

ltcfcomponent displayName"Example3"
output"false"gt ltcffunction name"test"
returnType"string" access"public"
output"false"gt ltcfargument name"argone"
type"string" required"true"gt ltcfset var i
0gt ltcfloop index"i" from1 to10gt
..... lt/cfloopgt lt/cffunctiongt
lt/cfcomponentgt
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Understand Data Scopes

• Variables
• This
• Arguments
• Function Local

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Cache CFC Instances

• CFC creation can be slow.
• Use createObject/cfobject to create an instance.
• ltcfinvokegt (typically) works with new instances.

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Pseudo-Constructor

• Any code not inside ltcffunctiongt.
• Useful to initialize variables.
• BlueDragon has ltcfconstructorgt

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Dealing with Application Variables

• Application.cfm and when it's run
• Flash Remoting/WS calls
• Same folder
• Don't rely on it!
• Application CFC

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Inheritance/Super

• Use for Is-A, not Has-A
• In other words, inheritance is used when a CFC
  defines as "is a" relationship with it's parent.
  It should not be used for simple code re-use.
• Super allows for a child method to extend a
  parent method.

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Pass by Ref/by Value

• Values passed to CFC methods follow the same
  rules as values passed to UDFs.
• The following are passed by reference
• Structures
• Queries
• Other "comlpex" objects (including CFCs)

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Resources

• www.cfczone.org
• cfcdev mailing list
• Top Ten Tips article by Rob Brooks-Bilson
• http//www.oreillynet.com/pub/a/javascript/2003/09
  /24/coldfusion_tips.html?page1
• CFC Best Practices by Nathan Dintenfass
• http//www.dintenfass.com/cfcbestpractices/