How to include UDF_library in application.cfm? - coldfusion

I am using ColdFusion 8.0.1
I am working on an existing application that has thousands of pages. I am trying to include a library of new UDFs in my application.cfm file.
I addedd this line to application.cfm:
<!--- UDF library include --->
<cfinclude template="UDF/udf_library.cfm">
The UDF library includes other files that contain UDFs, like this:
<cfinclude template="udf_powerreview.cfm">
I have functions in the udf_powerreview.cfm file, such as:
// CREATE POWER REVIEWS SNIPPET
function createPRSnippet(Page_ID) {
LOCAL.Page_ID = ARGUMENTS.Page_ID;
if (isNumeric(LOCAL.Page_ID) && LOCAL.Page_ID > 0) {
LOCAL.Snippet = "<div class='pr_snippet_product'><script type='text/javascript'>var pr_snippet_min_reviews = 0; POWERREVIEWS.display.snippet(document, { pr_page_id : '#LOCAL.Page_ID#' });</script></div>";
} else {
LOCAL.Snippet = "";
}
return LOCAL.Snippet;
}
The debugging tool says that UDF/udf_library.cfm and udf_powerreview.cfm are being successfully included.
The problem is when I call the function in another page, I get an error that says that function doesn't exist. When I can copy the function and put it directly into the page that it is used in and it works just fine. And, I do not get the error "routines can not be declared twice".
In every site that I build, I create a udf_library.cfm or udf_library.cfc in the exact same manner. They always work fine.
What might prevent the functions from being available and accessed? Is there an application setting that needs to be set?

It's a page scope issue. Don't think of the Application.cfm as an include on all your pages, just know that it runs first. Somethings it initializes will carry over to your existing page scope and some things won't. Using an Application.cfc instead of an application.cfm takes care of much of the ambiguity.
To make your UDF's available to your whole application, I would suggest using a "Singleton" Design pattern. First take your UDF's and put them in a CFC format. This will make them more portable.
in your application.cfm you could put the following lines:
<cfif NOT isdefined('session.udf_powerreview') or isdefined('url.resetudf')>
<cfset session.udf_powerreview = createobject('Component','udf.udf_powerreview')/>
<!--- this 'udf.udf_powerreview' represents the physical path udf/udf_powerreview.cfc --->
</cfif>
I'm stuffing it in the session scope instead of the application scope, becuase you won't have an good way of resetting the application scope if you modify your UDF's.
Either way, once this is in your application.cfm you should be able to see your functions on any page.
<cfdump var="#session.udf_powerreview#">

Here is one strategy that I use. This basically calls the UDFs "on demand". It won't reimport the UDFs if it already exists. You do however have to have named arguments however, otherwise you'd have to strip out the UDFName out of the argument collection. I'm worried however that argument order might not be preserved, I haven't investigated that.
application.cfm
<cfapplication
name="udftest_001" />
<cffunction name="udf">
<cfargument name="udfname" type="string" required="true">
<cfif NOT isDefined(udfname)>
<cfinclude template='./udfs/#udfname#.cfm'>
</cfif>
<cfset tempfunc = variables[udfname]>
<cfreturn tempfunc(argumentCollection=arguments)>
</cffunction>
index.cfm
<cfoutput>
#udf(udfname='testUDF',firstname='John',lastname='Smith')#<br/>
#udf(udfname='testUDF',firstname='Betty',lastname='Ford')#<br/>
</cfoutput>
/udfs/testudf.cfm
<cfscript>
function testUDF() {
return 'Hello ' & arguments.firstname & ' #arguments.lastname#';
}
</cfscript>

I suspect something is up with relative paths.
Can you make "UDF" a mapping? Then you can do
<cfinclude template="/UDF/udf_library.cfm">

Related

In ColdFusion, what is the difference between setting a function to a variable and calling a function in hashtags?

I wrote the following function:
<cffunction name="check_session_valid" returntype="boolean">
<cfif NOT StructKeyExists(session,"username") OR (len(session.username) EQ 0)>
<script>location.href = 'logout.cfm'</script>
<cfabort>
</cfif>
<cfset session.myApp_start = now()>
<cfreturn true>
</cffunction>
In my .cfm page, I can call that function using
<cfset session_valid = application.lib.check_session_valid()>
OR
#application.lib.check_session_valid()#
What's the difference? Best practice?
Since you asked about best practice, which is a matter of opinion, I think you can improve your function by having it returning either true or false depending on whether or not session.username exists and has a length greater than 0. Then you can use it like this:
<cfif application.lib.check_session_valid()>
code for this condition
<cfelse>
<cflocation href = "logout.cfm">
<!--- note that cfabort is not necessary --->
<cfif>
Regarding your specific question, I think the extra variable, session_valid, is a waste of typing. However, that is simply my opinion.
Not related to your question, I found it curious that you would direct users to a page called logout.cfm. Often users are directed to a page that allows them to log in.
To be honest, both are valid and both would be considered best practice depending on what you are trying to do.
My rule of thumb is if I will need to use the result of a function call more than once, I will set it to a variable
myResult = application.lib.check_session_valid();
If I will only need to use the variable once I would do what Dan mentioned
if( application.lib.check_session_valid() ){
// Do stuff
}
The difference between the examples you showed are
<cfset session_valid = application.lib.check_session_valid()>
This will set the variable named session_valid to whatever is returned from the call to check_session_valid().
#application.lib.check_session_valid()#
This will, in .cfm pages, simply render the value returned from the call to check_session_valid() assuming it is inside of a <cfoutput> tag. There are other places this would also render the value, such as inside a <cfsavecontent>.

How do I access a UDF library in the APPLICATION scope using a shortened name?

I am using ColdFusion 8.0.1.
I created a UDF library and put it in a CFC. I load the library in the APPLICTION scope like this:
// CREATE STRUCTURE OBJECTS
if (not isDefined("APPLICATION.AppOBJ") or not isStruct(APPLICATION.AppOBJ)) {
APPLICATION.AppOBJ = structNew();
APPLICATION.AppOBJ.udf_library = createObject("component", "udf.udf_library");
}
The library works great! But I want to reduce the code needed to access the functions, to shorten the reference. Currently, I have to access the functions like this:
APPLICATION.AppOBJ.udf_library.myFunction();
I want to be able to reference this library object as "UDF", like this:
UDF.myFunction();
In another ColdFusion 9 project (Again, this is a CF8 project!), I am able to do this right after I create the ojbect
<cfset udf = APPLICATION.AppOBJ.udf_library>
In the current project, this doesn't work in the application.cfm file. It DOES however, work when I put it on the page that it is being used.
My question is how far upstream can I put this last line of code to have the variable available on any page in the application? Is there a difference between CF8 and CF9 for this type of thing? Is the difference because I am working in application.CFM versus application.CFC?
Thanks!!!
-- EDIT -- MORE INFORMATION ---
The files that I am trying to access the APPLICATION.AppOBJ.udf_library object are within a custom tag. Might that matter?
-- ANSWER -- THANKS TO MICAH AND BEN NADEL ---
I haven't tried this yet but I think it should work as the idea comes from Ben Nadel's blog entry entitled Creating Globally Accessible User Defined Functions In ColdFusion (Safer Version)
<cfcomponent output="false" hint="I define the application settings and event handlers.">
<!--- Define the application. --->
<cfset this.name = "TestApp" >
<cfset this.applicationTimeout = createTimeSpan( 0, 0, 5, 0 ) >
<!---
Add all of our "global" methods to the URL scope. Since
ColdFusion will automatically seach the URL scope for
non-scoped variables, it will find our non-scoped method
names.
--->
<cfset structAppend( url, createObject( "component", "udf.udf_library" ) ) >
</cfcomponent>
You should now be able to access MyFunction() globally.
If you want to access the function as UDF.MyFunction() then I think you should be able modify Ben's example to the following:
<cfset UDF = StructNew() >
<cfset structAppend( UDF, createObject( "component", "udf.udf_library" ) ) >
<cfset structAppend( url, UDF ) >

Get names of functions injected into CFC?

I am using the technique detailed in this answer to manage a library of small utility functions. (Essentially, each function is loaded as a "mix-in" using cfinclude.)
I have need, however, to know the names of the functions that the object has (once instantiated). A cfdump on the object only shows the init function which is written directly in the CFC.
Some more detail:
I am creating the object in the application scope in OnApplicationStart().
<cfset application.udfs=createObject("component","extensions.udfs").init()>
However, to save the developers from having to constantly write application.udfs.foo(), I thought I'd grab all of the functions and drop them in to the variables scope in OnRequestStart(), so that these hypothetical developers could just write foo().
<cfset foo=application.udfs.foo>
Obviously, though, this needs to be dynamic and to happen for each of the functions in the object, no matter how many there are. If I repeat this line for every function I've lost whatever I'd gained by having a library that is dynamically generated.
I thought perhaps I could use a collection loop, but that was invalid. I am fairly certain there's a way to get the list of methods in an object, but I have not yet been able to find it.
Any clues?
By the by, my fallback is going to be to copy the application.udfs object to a local object with a nice short name (like "u") so that the developers can simply type u.foo(), so no need to suggest that if what I want to do can't be done.
This should allow you to import all your udfs into the global variables scope:
StructAppend(variables, application.udfs);
I think GetMetaData should help you.
Here another interesting option suggested by Ben Nadel:
Check out the detail in his blog entry: http://www.bennadel.com/blog/1776-Creating-Globally-Accessible-User-Defined-Functions-In-ColdFusion-Safer-Version-.htm
UDF.cfc
<cfcomponent
output="false"
hint="I define user defined functions.">
<cffunction
name="getMessage"
access="public"
returntype="string"
output="false"
hint="I return a test message.">
<cfreturn "I am defined in the UDF component" />
</cffunction>
</cfcomponent>
Application.cfc
<!--- Define the application. --->
<cfset this.name = hash( getCurrentTemplatePath() ) />
<cfset this.applicationTimeout = createTimeSpan( 0, 0, 5, 0 ) />
<!---
Add all of our "global" methods to the URL scope. Since
ColdFusion will automatically seach the URL scope for
non-scoped variables, it will find our non-scoped method
names.
--->
<cfset structAppend(
url,
createObject( "component", "UDF" )
) />

Requesting an Application.cfc Element of 'THIS'

If this has been asked before I apologize but I wasn't able to get a solid enough understanding without some assistance ....
I have a Local ColdFusion9 App that I use for development and testing running on WinXP SP3 with Apache 2 ...
What I'm having a problem understanding how to call request elements passed from the Application's 'THIS' scope to the onRequestStart() method.
For instance, My Application.cfc has the following in 'THIS' ...
<!--- MY 'THIS' Statements in Application.cfc --->
<cfscript>
/* define custom coldfusion mappings. Keys are mapping names, values are full paths */
this.mappings = structNew();
this.mappings['/tags'] = ExpandPath('/cfdev/tags');
</cfscript>
Further into my Application.cfc I have the following in the onRequestStart() function ...
<!--- Run before the request is processed --->
<cffunction name="onRequestStart" returnType="boolean" output="false">
<cfargument name="thePage" type="string" required="true">
<cfinclude template="#arguments.thePage#">
<!--- Lot's of onRequest statements and then ... --->
<cfset request.mappings = #THIS.mappings#>
<cfreturn true>
</cffunction>
Now ... Supposing I have a page where I call <cfdump var="#request.mappings#"> ...
I get an error stating 'Element MAPPINGS is undefined in REQUEST.' ...
However, (here's where my confusion begins) ... If I call <cfdump var="#request#"> Two structures are returned ... The first containing a key for "cfdumpinited" with a value of 'False' and the second with the structKey 'mappings' which contains another struct with a key of '/tags' and a value of 'C:\vir_dir\CFDEV\tags' as one would expect ...
If someone could please explain why it is that request succeeds yet request.mappings fails as I'm a bit in the woods here ... ;-)
Follow the logic through:
a request is made
onRequestStart runs
you explicitly include the template requested
youTHEN set request.mappings = this.mappings
onrequeststart finishes
the template requested executes
So if you have this in your requested template:
<cfdump var="#request.mappings#>
Then when you include that file at step 3... request.mappings doesn't exist yet (as they are created in step 4).
However when you change it to:
<cfdump var="#request#>
Then there's no error condition, so your CFINCLUDE runs fine, but DOESN'T OUTPUT ANYTHING (because you have output="false" on the function definition.
The dump you are seeing is the one coming from CF executing the requested template (step 6), by which time request.mappings exists.
I think you are confusing onRequestStart() with onRequest(), to be honest. It's in onRequest() that one might explicitly include the requested template, because onRequest() runs INSTEAD of CF running the requested template automatically. One would not generally include the requested template in onRequestStart() because it'll end up running twice.
Make sense?
I'm late to the party here, and may be missing a key element, but why not do this:
application.mappings = structNew()
instead of
this.mappings = structNew()
that way, you only set them once (on application start), you have access to them across your whole application, and you don't have the extra overhead of setting the request scope on every page hit.

Is onApplicationStart is good Idea in ColdFusion?

I have to use a Variable(Query Resultset) in ColdFusion, which will get the results from Other Application DB, and stores in Coldfusion Application.
The main idea is that I need to call the other Application DB only at Server startup time and cache the results in local. And I need to read the variable in other pages in my Application. I won't overwrite that variable in any page.
On googling I found that 'onApplicationStart' is useful to assign the variables at Application Startup time.
Is using the onApplicationStart fine or is there any other way? We can assign a variable at startup time(one time).
If onApplicationStart is fine: how to use? Maybe any link where it is explained clearly is helpful.
Well, it depends. How often will this query data be updated? If it really is unchanging, then onApplicationStart() is a fine place to put it. However, if it will change every so often, you can just tell Coldfusion to cache the query for a certain period of time, then you don't need to mess with onApplicationStart(), but rather when you call the query it will return the cached result automatically (within your specified time period).
Regardless, I would write a custom function to retrieve the data. Then it will be trivial to call it from onApplicationStart() or elsewhere.
Startup.cfc: (Named whatever you like)
<!--- Replace the datasource name with your db name --->
<cffunction name="getStartupQuery" hint="Returns a query recordset for startup">
<cfargument name="datasource" required="no" type="string" default="OtherAppDB">
<!--- Init the query variable --->
<cfset var result = queryNew("id")>
<!-- Get the query dataset --->
<cfquery name="result" datasource="#arguments.datasource#">
YOUR QUERY HERE
</cfquery>
<cfreturn result>
</cffunction>
Application.cfc: (Just the important parts)
<cffunction name="onApplicationStart">
<!--- init the startup.cfc, then retrieve the data
and save it to the application scope. Remember the component name must match
your component above --->
<cfset var startup = createObject("component", "startup")>
<cfset application.varFromOtherDB = startup.getStartupQuery()>
<cfreturn true>
</cffunction>
Now, you should be able to access this variable from any CFM or CFC in your application using:
<cfset myNewVar = application.varFromOtherDB>
or
#application.varFromOtherDB#
IF you use the onApplicationStart() method, I highly recommend implementing a method to reinit the application. For an example, see this other discussion.