cfflush

Last updated on Aug 14, 2024 | Also applies to ColdFusion

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CFML Reference User Guide

ColdFusion functions

ColdFusion functions by category
Functions a-b
1. Abs
2. ACos
3. AddSOAPRequestHeader
4. AddSOAPResponseHeader
5. AjaxLink
6. AjaxOnLoad
7. ApplicationStop
8. ArrayAppend
9. ArrayAvg
10. ArrayClear
11. ArrayContains
12. ArrayContainsNoCase
13. ArrayDelete
14. ArrayDeleteAt
15. ArrayDeleteNoCase
16. ArrayEach
17. ArrayFilter
18. ArrayFind
19. ArrayFindAll
20. ArrayFindAllNoCase
21. ArrayFindNoCase
22. ArrayInsertAt
23. ArrayIsDefined
24. ArrayIsEmpty
25. ArrayLen
26. ArrayMap
27. ArrayMax
28. ArrayMin
29. ArrayNew
30. ArrayPrepend
31. ArrayReduce
32. ArrayResize
33. ArraySet
34. ArraySetMetadata
35. ArraySlice
36. ArraySort
37. ArraySum
38. ArraySwap
39. ArrayToList
40. Asc
41. ASin
42. Atn
43. AuthenticatedContext
44. AuthenticatedUser
45. BinaryDecode
46. BinaryEncode
47. BitAnd
48. BitMaskClear
49. BitMaskRead
50. BitMaskSet
51. BitNot
52. BitOr
53. BitSHLN
54. BitSHRN
55. BitXor
56. BooleanFormat
Functions-c-d
Functions-e-g
Functions-h-im
Functions-in-k
Functions-l
Functions-m-r
Functions-s
Functions-t-z
1. Tan
2. ThreadJoin
3. ThreadTerminate
4. Throw
5. TimeFormat
6. ToBase64
7. ToBinary
8. ToScript
9. ToString
10. Trace
11. Transactionandconcurrency
12. TransactionCommit
13. TransactionRollback
14. TransactionSetSavePoint
15. Trim
16. UCase
17. URLDecode
18. URLEncodedFormat
19. URLSessionFormat
20. Val
21. ValueList
22. VerifyClient
23. Week
24. Wrap
25. WriteDump
26. WriteLog
27. WriteOutput
28. WSGetAllChannels
29. WSGetSubscribers
30. WSPublish
31. WSSendMessage
32. XmlChildPos
33. XmlElemNew
34. XmlFormat
35. XmlGetNodeType
36. XmlNew
37. XmlParse
38. XmlSearch
39. XmlTransform
40. XmlValidate
41. Year
42. YesNoFormat

ColdFusion tags

ColdFusion tag summary
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
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
Tags a-b
Tags c
Tags f
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
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
Tags j-l
Tags m-o
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
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
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
Tags u-z
1. cfupdate
2. cfwddx
3. cfwebsocket
4. cfwindow
5. cfxml
6. cfzip
7. cfzipparam

CFML Reference

Cloud services

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
  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
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

Flushes currently available data to the client.

Syntax

Note: You can specify this tag's attributes in an attributeCollection attribute whose value is a structure. Specify the structure name in the attributeCollection attribute and use the tag's attribute names as structure keys.

Attributes

Attribute	Req/Opt	Default	Description
interval	Optional		Integer. Flushes output each time this number of bytes becomes available. HTML headers, and data that is already available when the tag is executed, are omitted from the count.

Usage

The first occurrence of this tag on a page sends back the HTML headers and any other available HTML. Subsequent cfflush tags on the page send only the output that was generated after the previous flush.
When you flush data, ensure that enough information is available, as some browsers might not respond if you flush only a small amount. Similarly, set the interval attribute for a few hundred bytes or more, but not thousands of bytes.Use the interval attribute only when a large amount of output is sent to the client, such as in a cfloop or a cfoutput of a large query. Using this form globally (such as in the Application.cfm file) might cause unexpected errors when CFML tags that modify HTML headers are executed. Because the cfflush tag sends data to the browser when it executes, it has several limitations, including the following:

Using any of the following tags or functions on a page anywhere after the cfflush tag can cause errors or unexpected results: cfcontent, cfcookie, cfform, cfheader, cfhtmlhead, cflocation, and SetLocale. Similarly, do not use any tags that use AJAX features, including cfdiv, cflayout, cflayoutarea, cfpod, cfsprydataset, cftooltip, cfwindow, or HTML format cfgrid, cftree, cftextarea, or cfinput (using autosuggest or datefield attributes) tags. All of the preceding tags and functions normally modify the HTML header, but cannot do so after a cfflush tag, because the cfflush sends the header.
Using the cfset tag to set a cookie anywhere on a page that has a cfflush tag does not set the cookie in the browser.
Using the cfflush tag in the body of several tags, including cfsavecontent, cfquery, and custom tags, causes errors.

If you save Client variables as cookies, any client variables that you set after a cfflushtag are not saved in the browser.

Note: Normally, the cferror tag discards the current output buffer and replaces it with the contents of the error page. The cfflush tag discards the current buffer. As a result, the Error.GeneratedContent variable resulting from a cferror tag after a cfflush contains any contents of the output buffer that has not been flushed. This content is not sent to the client. The content of the error page displays to the client after the bytes that have been sent.

To disable webserver buffer, change the iis_buffer_enable to false in the cfroot\config\wsconfig\1\isapi_redirect.properties file. Disable webserver buffer if you want cfflush to work over an IIS connector. If your application does not use cfflush , set it to true for increase in the performance.

Example

The following example uses cfloop tags and the rand random number generating function to delay data display. It simulates a page that is slow to generate data.

<h1>Your Magic numbers</h1>

<p>It will take us a little while to calculate your five magic numbers. It takes a lot of work to find numbers that truly fit your personality. So relax for a minute or so while we do the hard work for you.</p>

Magic number #Myindex# is:  #RandRange(100000, 999999)#<br><br>

</cfoutput>

</cfloop>

<p>If you saw no delay between lines being written (and instead they were written all at once after a few seconds delay), and you're making this request via IIS,

note that you need to set iis_buffer_enable=false in the isapi_redirect.properties file, as discussed in the docs here, and then restart your IIS site to pick up the change to that file.</p>

<h1>Your Magic numbers</h1> <p>It will take us a little while to calculate your five magic numbers. It takes a lot of work to find numbers that truly fit your personality. So relax for a minute or so while we do the hard work for you.</p> <cfflush> <cfset sleep(1000)> <cfflush interval=10>  <cfloop index="Myindex" from="1" to="5" step="1"> <cfset sleep(1000)> <cfoutput> Magic number #Myindex# is:  #RandRange(100000, 999999)#<br><br> </cfoutput> </cfloop> <p>If you saw no delay between lines being written (and instead they were written all at once after a few seconds delay), and you're making this request via IIS, note that you need to set iis_buffer_enable=false in the isapi_redirect.properties file, as discussed in the docs here, and then restart your IIS site to pick up the change to that file.</p>

<h1>Your Magic numbers</h1>
<p>It will take us a little while to calculate your five magic numbers. It takes a lot of work to find numbers that truly fit your personality. So relax for a minute or so while we do the hard work for you.</p>
<cfflush>
<cfset sleep(1000)>
 
<cfflush interval=10>
<!--- Now slowly output 5 random numbers, flushing the buffer for every 300 bytes accumulated. --->
<cfloop index="Myindex" from="1" to="5" step="1">
  <cfset sleep(1000)>
  <cfoutput>
  Magic number #Myindex# is:&nbsp;&nbsp;#RandRange(100000, 999999)#<br><br>
  </cfoutput>
</cfloop>
 
<p>If you saw no delay between lines being written (and instead they were written all at once after a few seconds delay), and you're making this request via IIS,
note that you need to set iis_buffer_enable=false in the isapi_redirect.properties file, as discussed in the docs here, and then restart your IIS site to pick up the change to that file.</p>

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cfflush

Description

Category

Syntax

See also

Attributes

Usage

Example

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