Building a CF Library

1
Building a CF Library

• What is a library, and advantages
• Different types of CF libraries
• When to use CF includes versus CF modules
• How a ttTools library works, advantages over a CF
  module.

2
What is a code library

• Pieces of code that are written once, used many
  times

3
Advantages of a library (Part 1)

• Isolates code, so it is easer to re-use, both for
  the current project, and any future projects.
• Isolates code and variables, so it is easier to
  debug
• Make your own tool set that you are familiar
  with, improve and add to over time, and take
  with you as you move to your next job.
• Make code that you can easily share with other
  programmers or resell
• Categorize your code by TYPE/CLASS, in
  subdirectories

4
Advantages of a library (Part 2)

• Make a tool set that your company uses for
  projects, help enforce a uniform, company wide
  programming style
• Help ensure new programmers get up to speed
  faster with better code.
• If a library function is used many times, a
  single change to the function makes a global
  change to the web site. This can be quite
  powerful.

5
Different kinds of CF libraries

• CF Includes
• CF Modules
• Local Modules
• Global Modules
• ttTools Modules
• CFX
• CF Script

6
ltCFINCLUDE template/mypath/mytemplate.cfmgt
Includes (Part 1)

• Is a an extension of the current page, the code
  is simply located somewhere else.
• Any variables available to the page is available
  to the include
• Easier to use since it does not require passing
  in formal parameters
• Can easily cause programming errors due to
  undefined variables, or re-use of variable names
  that are the same as page variables!

7
How to Make CF Includes Library Friendly

• Try not to use!, especially on large projects
• Use CFPARAM for EVERY VARIABLE in the include
• Try to name variables that will be unique to the
  include.
• Only return a limited number of variables with
  special names.
• Make a special directory for includes, with
  sub-directories by type or class

8
CF Modules

• Accept defined INPUT parameters, know as
  attributes in CF
• Can return variables (caller.variablename)
• Cannot access page variables, so variables are
  isolated (this is a good thing!)
• Can return page variables
• Provide for some advanced CF features, such as
  child/dependant tags and open and close tags (not
  covered here)

9
CF Modules

• CFMODULE tag
• Global modules
• CF_TEMPLATENAME Method
• ttTools Method

10
CFMODULE tag

• ltCFMODULE template/mypath/mytemplatename.cfm
  var1string1 var2string2gt
• If it is a global tag, dont know where the tag
  actually is located, in case I want to edit it.

11
CF_TEMPLATENAME Method

• ltCF_MYTEMPLATE Var1string1 var2string2gt

12
Global modules

• Located in C\CFUSION\CUSTOMTAGS directory
• Global tag names must be unique for the entire
  server
• Sub directories of the CUSTOMTAGS directory can
  be used to categorize tags

13
How to Make CF MODULES Library Friendly

• Dont use local modules!
• Make a special directory for modules, separate
  from your pages
• Document any variables returned using Caller.
  method

14
ttTools Method

• A global module that calls local templates
• Allows templates to be found locally and
  categorized
• Allows for a global means of error handling and
  error logging
• Allows for a global means of white space
  stripping
• May allow for other global features I have not
  thought of

15
CFX (CF Executable)

• Much harder to write
• Usually purchased
• Requires C programming (and programmer!)
• Good for
• writing functions that requires close integration
  with operating system
• making a really fast web site
• making code this is secure
• making code that is hard to steal (ie, cannot be
  duplicated or put on another machine easily)

16
CF Script functions

• Dont know much about this, but looks promising
• Allows for formal CF functions, with both formal
  input AND output parameters.
• Runs faster than regular CF code
• Moves away from CF tag based programming, which
  was at the heart of why programmers love it

17
What makes a good Library tool?

• Code is convenient to edit
• Provides for formal input/output parameters
• Can be organized by type/class
• Easy to add Global Error Handling
• Easy to add Global Error Logging