User Guide

Table Of Contents
Validating data with the IsValid function and the cfparam tag 685
Using cftry and cfcatch tags
The self-posting form and action page looks as follows:
<!--- Use a Boolean variable to indicate whether all fields are good. --->
<cfset goodData="Yes">
<!--- Make sure the form was submitted. --->
<cfif isDefined("form.saveSubmit")>
<!--- The cftry block for testing the User ID value. --->
<cftry>
<!--- The cfparam tag checks the field data types. --->
<cfparam name="form.UserID" type="integer">
<!--- If the data is invalid, ColdFusion throws an expression exception. --->
<!--- Catch and handle the exception. --->
<cfcatch type="expression">
<!--- Set the data validity indicator to False. --->
<cfset goodData="No">
<cfoutput>
Invalid user ID.<br>
#cfcatch.detail#<br><br>
</cfoutput>
</cfcatch>
</cftry>
<!--- The cftry block for testing the e-mail address value. --->
<cftry>
<cfparam name="form.emailAddr" type="email">
<cfcatch type="expression">
<cfset goodData="No">
<cfoutput>
Invalid e-mail address.<br>
#cfcatch.detail#<br><br>
</cfoutput>
</cfcatch>
</cftry>
<!--- The cftry block for testing the telephone number value. --->
<cftry>
<cfparam name="form.phoneNo" type="telephone">
<cfcatch type="expression">
<cfset goodData="No">
<cfoutput>
Invalid telephone number.<br>
#cfcatch.detail#<br><br>
</cfoutput>
</cfcatch>
</cftry>
<!--- Do this only if the validity indicator was not set to False in a
validation catch block. --->
<cfif goodData>
<!--- Application code to update the database goes here. --->
<cfoutput>
<h3>The e-mail address and phone number for user #Form.UserID#
have been added</h3>
</cfoutput>
</cfif> <!--- goodData is True--->
</cfif> <!--- Form was submitted. --->