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Handling Error templates in FW/1 |
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This blog article describes how FW/1 looks for and uses an error handling template.
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Building Intelligent sessions into your framework |
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Have you ever been logged into an application and had your session timeout, then when you log back in you are returned to a different place altogether?
This article deals with a way to mark where a user was in your application and return them to that location when they log back in. It also allows a user to deep link into an application. IE when they have a bookmarked link instead of being passed to the home page, they are passed through to their original destination.
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Pre loading object (CFC) references in your Application.cfc |
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One of the best practices that I've been using more and more is ColdFusion's ability to add CFC object references to scopes. By this I mean that it is possible to create a shorter friendlier scoped variable that you use to reference your CFC's.
In your Application.cfc you can map out all your CFC references, this gives you a much shorter variable name to type each time, and it caches the CFC.
2
3<!--- scope out all the objects as application level vars --->
4<cfset application.formObj= createObject('component','dir.objName ')>
5<cfset application.siteObj= createObject('component','dir.objName')>
6<cfset application.mailObj= createObject('component','dir.objName')>
7<cfset application.config=createObject('component','dir.objName').getConfig(id=N)>
8
9</cffunction>
Put any references like this in the 'onApplicationStart' function. You do not need to lock the scope in this function, and if the code within it does not run successfully then it does not continue running the application. It will try again on the next page request.
The caching functionality here is great, not only will Coldfusion create a handy short name for CFC, but it will actually run through the code, and stop on any errors. If you deliberately introduce a code error into one of your objects you will see the Application halt and show you the error. For me this is reason enough to move all my business logic into CFC's. This essentially means that it is not possible for a user to get part of the way through a application and find an object based error.
Using this in conjunction with a framework such as FuseBox allows you to load, parse and cache the CFC object, all before your actual display layer has been invoked.
The example below uses the FuseBox function 'onFuseboxApplicationStart' of starting an Application.
2 <cfset super.onFuseboxApplicationStart() />
3<!--- scope out all the objects as application level vars --->
4
5<cfset application.formObj= createObject('component','dir.objName ')>
6<cfset application.siteObj= createObject('component','dir.objName')>
7<cfset application.mailObj= createObject('component','dir.objName')>
8<cfset application.config=createObject('component','dir.objName').getConfig(id=N)>
9
10
11</cffunction>
Changing the 'fusebox_parameters.mode' value allows you to set this caching at an environmental level, so no caching for development, or caching for live
2Or
3<cfset FUSEBOX_PARAMETERS.mode = "production">
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Passing url variables through Isapi re write - Regular Expression |
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One of the more common tasks in ColdFusion development is passing variables through the URL string. We are all familiar with the idea that the question mark (?) denotes the url query string start, and that name value pairs are separated with the ampersand (&).
I usually avoid using this in display templates, as it isn't great exposing your internal site workings to customers, and with Fusebox it is very easy to pass the URL variables to an "act_" template and remain hidden.
What happens when you want to use dynamic url variables with a URL re writing application like Isapi re write? I've been using Isapi re write in some FuseBox framework application, and it is relatively easy to set up a rewrite rule, as shown below.
Where the url /home/ would actually serve up the content specified in the fuse specified. But this is hard coded. What about dynamic variables?
We can create a regular expression to handle the translation of the variables.
We use a similar URL, but append the dollar ($) 1 = dollar ($) 2 string. In the re write rule we specify that appended variables are transposed into the string using the slash (/) as a separator.
So as an example we could pass a product id of 24 into the rule like this:
2RewriteRule buy/(.*)/(.*)/ index.cfm?go=cart.buy&$1=$2
It would be rewritten to the more familiar url string. A handy way of continuing to mask the url.
