User Guide Cancel

cfparam

Last updated on May 30, 2024 | Also applies to ColdFusion

CFML Reference User Guide
ColdFusion functions
ColdFusion Tags
1. ColdFusion tag summary
2. ColdFusion tags by category
  1. Application framework tags
    1. cfapplication
    2. cfassociate
    3. cferror
    4. cfimport
    5. cfinterface
    6. cflock
    7. cfscript
    8. cfthread
  2. Communications tags
  3. Database manipulation tags
  4. Data output tags
    1. cfchart
    2. cfchartdata
    3. cfchartseries
    4. cfcol
    5. cfcontent
    6. cfdocument
    7. cfdocumentitem
    8. cfdocumentsection
    9. cfflush
    10. cfheader
    11. cflog
    12. cfoutput
    13. cfpresentation
    14. cfpresentationslide
    15. cfpresenter
    16. cfprocessingdirective
    17. cfprint
    18. cfreport
    19. cfreportparam
    20. cfsilent
    21. cftable
  5. Debugging tags
    1. cfdump
    2. cftimer
    3. cftrace
  6. Exception handling tags
    1. cfcatch
    2. cferror
    3. cffinally
    4. cfrethrow
    5. cfthrow
    6. cftry
  7. Extensibility tags
    1. cfchart
    2. cfchartdata
    3. cfchartseries
    4. cfcollection
    5. cfcomponent
    6. cfexecute
    7. cfftp
    8. function
    9. cfindex
    10. cfinterface
    11. cfinvoke
    12. cfinvokeargument
    13. cfobject
    14. cfproperty
    15. cfreport
    16. cfreportparam
    17. cfreturn
    18. cfsearch
    19. cfsharepoint
    20. cfspreadsheet
    21. cfwddx
    22. cfxml
  8. File management tags
    1. cfdirectory
    2. cffile
    3. cffileupload
    4. cfftp
    5. cfzip
    6. cfzipparam
  9. Flow-control tags
    1. cfabort
    2. cfbreak
    3. cfcase
    4. cfcontinue
    5. cfdefaultcase
    6. cfelse
    7. cfelseif
    8. cfexecute
    9. cfexit
    10. cfif
    11. cfinclude
    12. cflocation
    13. cfloop
    14. cfrethrow
    15. cfswitch
    16. cfthrow
    17. cftry
  10. Forms tags
    1. cfapplet
    2. cfcalendar
    3. cffileupload
    4. cfform
    5. cfformgroup
    6. cfformitem
    7. cfgrid
    8. cfgridcolumn
    9. cfgridrow
    10. cfgridupdate
    11. cfinput
    12. cfpdf
    13. cfpdfform
    14. cfpdfformparam
    15. cfpdfparam
    16. cfpdfsubform
    17. cfselect
    18. cfslider
    19. cftextarea
    20. cftree
    21. cftreeitem
  11. Internet Protocol tags
    1. cfajaximport
    2. cfajaxproxy
    3. cfftp
    4. cffeed
    5. cfimap
    6. cfhttp
    7. cfhttpparam
    8. cfldap
    9. cfmail
    10. cfmailparam
    11. cfmailpart
    12. cfpop
    13. cfsprydataset
  12. Page processing tags
    1. cfcache
    2. cfcontent
    3. cfflush
    4. cfheader
    5. cfhtmlhead
    6. cfinclude
    7. cfprocessingdirective
    8. cfsetting
    9. cfsilent
  13. Security tags
  14. Variable manipulation tags
    1. cfcookie
    2. cfdump
    3. cfparam
    4. cfregistry
    5. cfsavecontent
    6. cfschedule
    7. cfset
    8. cfsetting
  15. Other tags
    1. cfimage
    2. cflog
    3. cfregistry
3. Tags a-b
4. Tags c
  1. cfcache
  2. cfcalendar
  3. cfcase
  4. cfcatch
  5. cfchart
  6. cfchartdata
  7. cfchartseries
  8. cfclient
  9. cfclientsettings
  10. cfcol
  11. cfcollection
  12. cfcomponent
  13. cfcontent
  14. cfcontinue
  15. cfcookie
  16. Tags d-e
5. Tags f
6. Tags g-h
  1. cfgraph
  2. cfgraphdata
  3. cfgrid
  4. cfgridcolumn
  5. cfgridrow
  6. cfgridupdate
  7. cfheader
  8. cfhtmlhead
  9. cfhtmltopdf
  10. cfhtmltopdfitem
  11. cfhttp
  12. cfhttpparam
7. Tags i
  1. cfif
  2. cfimage
  3. cfimap
  4. cfimapfilter
  5. cfimpersonate
  6. cfimport
  7. cfinclude
  8. cfindex
  9. cfinput
  10. cfinsert
  11. cfinterface
  12. cfinvoke
  13. cfinvokeargument
8. Tags j-l
9. Tags m-o
10. Tags p-q
  1. cfparam
  2. cfpdf
  3. cfpdfform
  4. cfpdfformparam
  5. cfpdfparam
  6. cfpdfsubform
  7. cfpod
  8. cfpop
  9. cfpresentation
  10. cfpresentationslide
  11. cfpresenter
  12. cfprint
  13. cfprocessingdirective
  14. cfprocparam
  15. cfprocresult
  16. cfprogressbar
  17. cfproperty
  18. cfquery
  19. cfqueryparam
11. Tags r-s
  1. cfregistry
  2. cfreport
  3. cfreportparam
  4. cfrethrow
  5. cfreturn
  6. cfsavecontent
  7. cfschedule
  8. cfscript
  9. cfsearch
  10. cfselect
  11. cfservlet
  12. cfservletparam
  13. cfset
  14. cfsetting
  15. cfsharepoint
  16. cfsilent
  17. cfslider
  18. cfspreadsheet
  19. cfsprydataset
  20. cfstoredproc
  21. cfswitch
12. Tags t
  1. cftable
  2. cftextarea
  3. cftextinput
  4. cfthread
  5. cfthrow
  6. cftimer
  7. cftooltip
  8. cftrace
  9. cftransaction
  10. cftree
  11. cftreeitem
  12. cftry
13. Tags u-z
  1. cfupdate
  2. cfwddx
  3. cfwebsocket
  4. cfwindow
  5. cfxml
  6. cfzip
  7. cfzipparam
CFML Reference
1. Reserved words and variables
2. Ajax JavaScript functions
3. ColdFusion ActionScript functions
4. ColdFusion mobile functions
5. Application.cfc reference
6. Script functions implemented as CFCs
7. ColdFusion Flash Form style reference
8. ColdFusion event gateway reference
9. ColdFusion C++ CFX Reference
10. ColdFusion Java CFX reference
11. WDDX JavaScript Objects
Cloud services

Description

Tests for the existence of a parameter (that is, a variable), validates its data, and, if a default value is not assigned, optionally provides one.

History

ColdFusion 10: Added the attribute {{maxLength}}

ColdFusion MX 7:

Added min, max, and pattern attributes.
Added creditcard, email, eurodate, float, integer, range, regex, regular_expression, ssn, social_security_number, time, URL, USdate, XML, and zipcode values of the type attribute.

Syntax

<cfparam 
name = "parameter name" 
default = "value" 
max = "value" 
maxLength = "number" 
min = "value" 
pattern = "regular expression" 
type = "data_type">

Attributes

Attribute	Req/Opt	Default	Description
name	Required		Name of the parameter (variable) to test (such as "Client.Email " or "Cookie.BackgroundColor "). If omitted, and if the parameter does not exist, an error is thrown.
default	Optional		Value to set parameter to if it does not exist. Any expression used for the default attribute is evaluated, even if the parameter exists. The result is not assigned if the parameter exists, but if the expression has side effects, they still occur.
max	Optional		The maximum valid value; used only for range validation.
maxLength	Optional		Used to specify the maximum character length of email, url, and string.
min	Optional		The minimum valid value; used only for range validation.
pattern	Optional		A JavaScript regular expression that the parameter must match; used only for regex or regular_expression validation.
type	Optional	any	The valid format for the data; one of the following. For detailed information on validation algorithms, see Validating form data using hidden fields in Validating data in the Developing ColdFusion Applications. any: any type of value. array: an array of values. binary: a binary value. boolean: a Boolean value: yes, no, true, false, or a number. creditcard: a 13-16 digit number conforming to the mod10 algorithm. date or time: a date-time value. email: a valid e-mail address. eurodate: a date-time value. Any date part must be in the format dd/mm/yy. The format can use /, -, or . characters as delimiters. float or numeric: a numeric value. guid: a Universally Unique Identifier of the form "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX" where X is a hexadecimal number. integer: an integer. query: a query object. range: a numeric range, specified by the min and max attributes. regex or regular_expression: matches input against pattern attribute. ssn or social_security_number: a U.S. social security number. string: a string value or single character. struct: a structure. telephone: a standard U.S. telephone number. URL: an http, https, ftp, file, mailto, or news URL. UUID: a ColdFusion Universally Unique Identifier, formatted XXXXXXXX-XXXX-XXXX-XXXXXXXXXXXXXXX, where X is a hexadecimal number. See CreateUUID. USdate: a U.S. date of the format mm/dd/yy, with 1-2 digit days and months, 1-4 digit years. variableName: a string formatted according to ColdFusion variable naming conventions. xml: XML objects and XML strings. zipcode: U.S., 5- or 9-digit format ZIP codes.

Usage

You can use this tag to make the following tests:

To test whether a required variable exists, use this tag with only the name attribute. If it does not exist, ColdFusion stops processing the page and returns an error.
To test whether a required variable exists, and that it is of the specified type, use this tag with the name and type attributes. If the variable does not exist or its value is not of the specified type, ColdFusion returns an error.
To set a default value for the variable, use this tag with the name and default attributes. If the variable does not exist, it is created and set to the default attribute value. If the variable exists, processing continues; the value is not changed.
If you specify variableName for the typeattribute, the parameter's value must be a string that is in ColdFusion variable name format; that is, starts with a letter, underscore (_), or Unicode currency symbol, and contains letters, numbers, underscores, periods, and Unicode currency symbols, only. ColdFusion does not check whether the parameter value corresponds to an existing ColdFusion variable.

Note:

To improve performance, avoid using the cfparam tag in ColdFusion functions, including in CFC methods. Instead, place the cfparam tags in the body of the CFML pages.

Example

<!--- This example shows how to use CFPARAM to define default values for page variables. ---> 
<cfparam name = "storeTempVar" default = "my default value"> 
<cfparam name = "tempVar" default = "my default value"> 

<!--- Check if form.tempVar was passed. ---> 
<cfif IsDefined("form.tempVar") is "True"> 
<!--- Check if form.tempVar is not blank. ---> 
<cfif form.tempVar is not ""> 
<!--- If not, set tempVar to value of form.tempVar ---> 
<cfset tempVar = form.tempVar> 
</cfif> 
</cfif> 

<body> 
<h3>cfparam Example</h3> 
<p>cfparam is used to set default values so that a developer does not have to 
check for the existence of a variable using a function like IsDefined.</p> 

<p>The default value of our tempVar is "<cfoutput>#StoreTempVar# </cfoutput>"</p> 

<!--- Check if tempVar is still the same as StoreTempVar and that tempVar is not blank. ---> 
<cfif tempVar is not #StoreTempVar# 
and tempVar is not ""> 
<h3>The value of tempVar has changed: the new value is 
<cfoutput>#tempVar#</cfoutput></h3> 
</cfif> 

<p> 
<form action = "cfparam.cfm" method = "post"> 
Type in a new value for tempVar, and hit submit:<br> 
<input type = "Text" name = "tempVar"> 
<input type = "Submit" name = "" value = "submit"> 
</form>

Adobe

Get help faster and easier

New user?

cfparam

Description

History

Category

Syntax

See also

Attributes

Usage

Example

Get help faster and easier

Ask the Community

Contact Us