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functioncoldfusionconstructor
Phillip Senn
Phillip Senn

Reputation: 47635

cffunction Access=

If I use access="remote" for binding a cfselect to a cfc, then I lose the ability to have an Init() constructor.

<cfselect name="CityID" bind="cfc:Components.City.View1({StateID})" value="CityID" display="CityName" bindonload="yes" />

I'm used to passing the datasource name to the Init function when I instantiate a component, like so:

<cfcomponent>
<cffunction name="Init">
<cfargument name="DS">

<cfset Variables.Instance.DS = arguments.DS>
<cfreturn This>
</cffunction>

<cffunction name="View1">
<cfset var qry = "">

<cfquery name="qry" datasource="#Variables.Instance.DS.Datasource#">
SELECT *
FROM Table
</cfquery>
<cfreturn qry>
</cffunction>
</cfcomponent>

Upvotes: 4

Views: 1298

Answers (4)

Goyuix
Goyuix

Reputation: 24370

What we have done: enacted a software development standard that outlaws any constructor code in our in-house developed components except a single (optional) invocation of the init() method. The so-called constructor code (anything inside the cfcomponent tag that is not inside a cffunction tag) will still get run in when the object is instantiated, and as a result before your method is actually called. 

<cfcomponent>

  <cfset init() />

  <cffunction name="init">
    <cfset variables.message = "Hello, World" />
    <cfreturn this />
  </cffunction>

  <cffunction name="remoteMethod" access="remote">
    <cfreturn variables.message />
  </cffunction>

</cfcomponent>

Upvotes: 1

Adam Tuttle
Adam Tuttle

Reputation: 19834

Phillip, what I usually do in this scenario is:

  1. Create the object in onApplicationStart, and store it to the Application scope. This is where you will initialize with your datasource other settings.
  2. Create a remote-proxy CFC that is basically a stub for the real thing, and bind your select field to that CFC.

onApplicationStart:

<cffunction name="onApplicationStart">
  <cfset application.dsn = "myDSN" />
  <cfset application.cityFinder = createObject("component", "Components.City").init(application.dsn) />
</cffunction>

And the remote proxy CFC:

<cfcomponent displayName="CityFinderProxy">
  <cffunction name="View1">
    <cfargument name="StateId" />
    <cfreturn application.cityFinder.View1(argumentCollection=arguments) />
  </cffunction>
</cfcomponent>

Note that I've left out a lot of best-practices (i.e. specifying argument types, required, etc) for brevity... so don't just copy and paste this example. I just wanted to illustrate the idea.

Upvotes: 5

Jas Panesar
Jas Panesar

Reputation: 6639

Is there a reason why you might not want to create your own remote init function that calls the one you can't reach for you?

Maybe a pain to do it that way.. just food for thought.

Upvotes: 1

Jason
Jason

Reputation: 1183

What is the question, exactly?

Setting a CFC to remote is basically making it a web service, so I guess that is why you wouldn't have the init() constructor.

You could easily set the datasource name in an application/session variable that created in the onApplicationStart portion of your application.cfc file.

Upvotes: 2

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