Form Validation-Client and Server

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Form Validation-Client and Server

• Verifying your visitors form submissions
• Jon Brundage
• CF developer/Section 508/web accessibility
• Jonwind_at_windcompany.com

2
Why validate?

• Safety
• protects your database and site
• Better user experience
• Makes your site more professional
• Saves time
• Less submits and page calls

3
Two types of Validation

• Client
• Via Scripting
• Javascript most common
• May be defeated by disabling JS in browser
• Poses risks but convenient
• Saves server load

• Server
• Via CGI/ASP etc
• This discussion focuses on the power of CF
• Cant be defeated by changes in browser settings
• Safer but less convenient

4
Client validation

• CFFORM
• Writes Javascript validation for you
• CFINPUT tag
• http//www.macromedia.com/support/coldfusion/ts/do
  cuments/cfform_hotfix.htm hotfix for CFMX 6.1
• Javascript
• Write your own
• Many free scripts available on the Web
• http//webdeveloper.earthweb.com/webjs/
• http//www.jsmadeeasy.com/
• http//www.js-examples.com/js/
• http//www.dynamicdrive.com/ (DHTML)

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Test for state of scripting on client

• Inside the FORM tag, add a NOSCRIPT tag with a
  hidden form field
• ltnoscriptgt
• ltinput type"hidden" name"scriptOff"
  value"scriptOff"gt
• lt/noscriptgt
• Use Isdefined(form.scriptOff) in action page with
  a CFIF tag to determine if you need to apply
  server side validation.

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Server validation

• CF functions
• CF tags
• CF custom tags- developers exchange
• CF structures and arrays

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CF STRUCTURE

• Contain variables called keys
• Create with a CFSET statement
• ltcfset formerrorsstructnew()gt
• A structure with elements contained in it will
  have a count similar to query recordcount
• ltcfif structcount(formerrors) gt "0"gt

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CF STRUCTURE cont.

• Structures may be looped.
• ltcfloop collectionformerrors item"ErrorType"gt
• ltul class"list"gt
• ltli style"color FF0000"gt
• formErrorserrorType
• lt/ligt
• lt/ulgt
• lt/cfloopgt

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Using a structure to hold errors

• ltcfset formerrorsstructnew()gt
• as errors encountered, add to structure
• ltcfset tempstructinsert(formerrors,"ErroruserFirs
  t","You failed to enter your first name."
  ,"yes")gt
• At the end of processing form errors, display by
  looping over the structure
• ltcfloop collectionformerrors item"ErrorType"gt
• ltul class"list"gt
• ltli style"color FF0000"gt
• formErrorserrorType
• lt/ligt
• lt/ulgt
• lt/cfloopgt

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Make use of CF functions

• IsNumeric
• Verify numeric fields
• Findoneof
• Look at characters
• And others!
• Use you creativity.

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THANK YOU

• Remember, CF has many tools at your disposal.
• Have fun, be creative and dont worry too much
  about being right
• Many ways to solve problems.
• Questions/comments-
• Jonwind_at_windcompany.com