Re: Using ScopeCache custom tag

Question

Hi, I am quite new to ColdFusion and I have a calendar that
is quite slow due to the cfloops it uses to build the calendar. As
the page does not change very often I wanted to use Raymond
Camden's ScopeCache custom tag. However, for some reason the custom
tag was not getting picked up from the custom tag folder on the
server. I have successfully used components so have tried to
convert the custom tag to a component but get the following error
message:
Routines cannot be declared more than once.
The routine scope_Cache has been declared twice in the same
file.
This is the component:
<!---
Name : scopeCache
Author : Raymond Camden ([email protected])
Created : December 12, 2002
Last Updated : November 6, 2003
History : Allow for clearAll (rkc 11/6/03)
: Added dependancies, timeout, other misc changes (rkc
1/8/04)
Purpose : Allows you to cache content in various scopes.
Documentation:
This tag allows you to cache content and data in various RAM
based scopes.
The tag takes the following attributes:
name/cachename: The name of the data. (required)
scope: The scope where cached data will reside. Must be
either session,
application, or server. (required)
timeout: When the cache will timeout. By default, the year
3999 (i.e., never).
Value must be either a date/time stamp or a number
representing the
number of seconds until the timeout is reached. (optional)
dependancies: This allows you to mark other cache items as
dependant on this item.
When this item is cleared or timesout, any child will also
be cleared.
Also, any children of those children will also be cleared.
(optional)
clear: If passed and if true, will clear out the cached
item. Note that
this option will NOT recreate the cache. In other words, the
rest of
the tag isn't run (well, mostly, but don't worry).
clearAll: Removes all data from this scope. Exits the tag
immidiately.
disabled: Allows for a quick exit out of the tag. How would
this be used? You can
imagine using disabled="#request.disabled#" to allow for a
quick way to
turn on/off caching for the entire site. Of course, all
calls to the tag
would have to use the same value.
License : Use this as you will. If you enjoy it and it helps
your application,
consider sending me something from my Amazon wish list:
http://www.amazon.com/o/registry/2TCL1D08EZEYE
--->
<cfcomponent>
<cffunction name="scope_Cache" access="public"
returntype="string">
<cfargument name="cachename" type="string"
required="yes">
<cfargument name="scope" type="string" required="yes">
<cfargument name="timeout" type="string"
required="yes">
<cfprocessingdirective pageencoding="utf-8">
<!--- allow for quick exit
<cfif isDefined("arguments.disabled") and
arguments.disabled>
<cfexit method="exitTemplate">
</cfif>
<!--- Allow for cachename in case we use cfmodule --->
<cfif isDefined("arguments.cachename")>
<cfset arguments.name = arguments.cachename>
</cfif>--->
<!--- Attribute validation --->
<cfif (not isDefined("arguments.name") or not
isSimpleValue(arguments.name)) and not
isDefined("arguments.clearall")>
<cfthrow message="scopeCache: The name attribute must be
passed as a string.">
</cfif>
<cfif not isDefined("arguments.scope") or not
isSimpleValue(arguments.scope) or not
listFindNoCase("application,session,server",arguments.scope)>
<cfthrow message="scopeCache: The scope attribute must be
passed as one of: application, session, or server.">
</cfif>
<!--- The default timeout is no timeout, so we use the
year 3999. --->
<cfparam name="arguments.timeout"
default="#createDate(3999,1,1)#">
<!--- Default dependancy list --->
<cfparam name="arguments.dependancies" default=""
type="string">
<cfif not isDate(arguments.timeout) and (not
isNumeric(arguments.timeout) or arguments.timeout lte 0)>
<cfthrow message="scopeCache: The timeout attribute must
be either a date/time or a number greather zero.">
<cfelseif isNumeric(arguments.timeout)>
<!--- convert seconds to a time --->
<cfset arguments.timeout =
dateAdd("s",arguments.timeout,now())>
</cfif>
<!--- create pointer to scope --->
<cfset ptr = structGet(arguments.scope)>
<!--- init cache root --->
<cfif not structKeyExists(ptr,"scopeCache")>
<cfset ptr["scopeCache"] = structNew()>
</cfif>
<cfif isDefined("arguments.clearAll")>
<cfset structClear(ptr["scopeCache"])>
<cfexit method="exitTag">
</cfif>
<!--- This variable will store all the guys we need to
update --->
<cfset cleanup = "">
<!--- This variable determines if we run the caching.
This is used when we clear a cache --->
<cfset dontRun = false>
<cfif isDefined("arguments.clear") and arguments.clear
and structKeyExists(ptr.scopeCache,arguments.name) and
thisTag.executionMode is "start">
<cfif
structKeyExists(ptr.scopeCache[arguments.name],"dependancies")>
<cfset cleanup =
ptr.scopeCache[arguments.name].dependancies>
</cfif>
<cfset structDelete(ptr.scopeCache,arguments.name)>
<cfset dontRun = true>
</cfif>
<cfif not dontRun>
<cfif thisTag.executionMode is "start">
<!--- determine if we have the info in cache already
--->
<cfif structKeyExists(ptr.scopeCache,arguments.name)>
<cfif
dateCompare(now(),ptr.scopeCache[arguments.name].timeout) is -1>
<cfif not isDefined("arguments.r_Data")>
<cfoutput>#ptr.scopeCache[arguments.name].value#</cfoutput>
<cfelse>
<cfset caller[arguments.r_Data] =
ptr.scopeCache[arguments.name].value>
</cfif>
<cfexit>
</cfif>
</cfif>
<cfelse>
<!--- It is possible I'm here because I'm refreshing. If
so, check my dependancies --->
<cfif structKeyExists(ptr.scopeCache,arguments.name) and
structKeyExists(ptr.scopeCache[arguments.name],"dependancies")>
<cfif
structKeyExists(ptr.scopeCache[arguments.name],"dependancies")>
<cfset cleanup = listAppend(cleanup,
ptr.scopeCache[arguments.name].dependancies)>
</cfif>
</cfif>
<cfset ptr.scopeCache[arguments.name] = structNew()>
<cfif not isDefined("arguments.data")>
<cfset ptr.scopeCache[arguments.name].value =
thistag.generatedcontent>
<cfelse>
<cfset ptr.scopeCache[arguments.name].value =
arguments.data>
</cfif>
<cfset ptr.scopeCache[arguments.name].timeout =
arguments.timeout>
<cfset ptr.scopeCache[arguments.name].dependancies =
arguments.dependancies>
<cfif isDefined("arguments.r_Data")>
<cfset caller[arguments.r_Data] =
ptr.scopeCache[arguments.name].value>
</cfif>
</cfif>
</cfif>
<!--- Do I need to clean up? --->
<cfset z = 1>
<cfloop condition="listLen(cleanup)">
<cfset z = z+1><cfif z gt 100><cfthrow
message="ack"></cfif>
<cfset toKill = listFirst(cleanup)>
<cfset cleanUp = listRest(cleanup)>
<cfif structKeyExists(ptr.scopeCache, toKill)>
<cfloop index="item"
list="#ptr.scopeCache[toKill].dependancies#">
<cfif not listFindNoCase(cleanup, item)>
<cfset cleanup = listAppend(cleanup, item)>
</cfif>
</cfloop>
<cfset structDelete(ptr.scopeCache,toKill)>
</cfif>
</cfloop>
<cfreturn scope_Cache>
</cffunction>
</cfcomponent>

Answer 1

Hi, thanks to both of you for your help. I reverted back the
custom tag and it was picked up this time - I don't know what
happened before. The functionality works as expected but I have hit
another problem and I am hoping I can tap your combined ColdFusion
wisdom to solve!!
The calendar returns leave records for staff and filters the
records using a querystring variable appended when the user clicks
on a particular month. However, what members of staff the user sees
depends on the data held in the users' session variables based on
their authority. The reason I wanted to use caching is because the
page takes a good ten seconds to run because of the use of cfloops
for the members of staff and the days of the week to dynamically
build the page. Using the custom tag would have worked if all
members of staff saw the same calendar data and could only see one
month. Can you see anyway I can speed up the page and do you think
caching is the way forward here?