Re: [CFCDev] Calling another CFC from within a method

Aldo d'Aquino Thu, 16 Oct 2003 16:03:23 -0700

I have already implemented the DAO Pattern using Abstract Factory Method.

At first implement an AbstractDAOFactory Interface with the following methods: create(dsn, cfcroot), getDAOFactory(factoryType) and specific abstract methods like getCustomerDAO(), getProductDAO()...

You also need to implement concrete DAO Factories for supported databases or any other kind of persistence, i.e. MSSQL, ORACLE and XML. These concrete DAO Factories will implement the abstract methods getCustomerDAO and getProductDAO listed above.

Now you have to implement the DAOs itself. The CustomerDAO should have the getCustomerById(), getAllCustomers(), insertCustomer(), updateCustomer() and deleteCustomer() methods. ProductDAO have similars methods.

Then, let me try to explain how it works. At application level, you create an instance of the abstract DAOFactory, where you call getDAOFactory("your_dsn", "MSSQL"). Based on the argument factoryType, the abstract factory returns an concrete DAOFactory of that type, i.e. MSSQL. With this concrete DAOFactory "in hands", you can get specific DAOs (i.e. Customers or Products) for any supported datasource type.

Below are some example codes.

AbstractDAOFactory

<cfcomponent displayname="AbstractDAOFactory">

<cfscript>
  this.dsn = "";
  this.cfcroot = "";
  this.MSSQL = 1;
  this.ORACLE = 2;
</cfscript>

<cffunction name="createDAOFactory" access="public" returntype="daofactory">
  
  <cfargument name="dsn" type="string" required="Yes">
  <cfargument name="cfcroot" type="string" required="Yes">

  <cfset this.dsn = arguments.dsn>
  <cfset this.cfcroot = arguments.cfcroot>

  <cfreturn this>
</cffunction>

<cffunction name="getDAOFactory"access="public" returntype="daofactory">
  
  <cfargument name="factoryType" type="numeric" required="Yes">

  
  <cfset var returndaofactory = "">

  <cfswitch _expression_="#arguments.factoryType#">
   <cfcase value="1">
    <cfinvoke component="#this.cfcroot#.dao.mssqldaofactory" method="createDAOFactory" returnvariable="returndaofactory" dsn="#this.dsn#" cfcroot="#this.cfcroot#">
   </cfcase>
   <cfcase value="2">
    <cfinvoke component="#this.cfcroot#.dao.oracledaofactory" method="createDAOFactory" returnvariable="returndaofactory" dsn="#this.dsn#" cfcroot="#this.cfcroot#">
   </cfcase>
  </cfswitch>

  <cfreturn returndaofactory>
</cffunction>

<cffunction name="getCustomerDAO" access="public" returntype="customerdao">
  <cfabort showerror="This Method is Abstract and needs to be overridden">
</cffunction>

<cffunction name="getProductDAO" access="public" returntype="productdao">
  <cfabort showerror="This Method is Abstract and needs to be overridden">
</cffunction>

</cfcomponent>

Concrete MSSQLDAOFactory

<cfcomponent displayname="MSSQLDAOFactory" extends="abstractdaofactory">

<cfscript>
  this.dsn = "";
  this.cfcroot = "";
</cfscript>


<cffunction name="createDAOFactory" access="public" returntype="mssqldaofactory">
  
  <cfargument name="dsn" type="string" required="Yes">
  <cfargument name="cfcroot" type="string" required="Yes">

  <cfset this.dsn = arguments.dsn>
  <cfset this.cfcroot = arguments.cfcroot>

  <cfreturn this>
</cffunction>

<cffunction name="getCustomerDAO" access="public" returntype="mssqlcustomerdao">
  
  <cfset var customerDAO = "">

  <cfinvoke component="#this.cfcroot#.dao.mssqlcustomerdao" method="createCustomerDAO" dsn="#this.dsn#" returnvariable="customerDAO ">

  <cfreturn customerDAO>
</cffunction>

<cffunction name="getProductDAO" access="public" returntype="mssqlproductdao">
  
  <cfset var productDAO = "">

  <cfinvoke component="#this.cfcroot#.dao.mssqlproductdao" method="createProductDAO" dsn="#this.dsn#" returnvariable="productDAO">

  <cfreturn productDAO>
</cffunction>

</cfcomponent>

MSSQLProductDAO

<cfcomponent displayname="MSSQLProductDAO" extends="productdao">

<cfscript>
  this.dsn = "";
</cfscript>


<cffunction access="public" name="createProductDAO" returntype="mssqlproductdao">
  
  <cfargument name="dsn" type="string" required="Yes">

  <cfset this.dsn = arguments.dsn>

  <cfreturn this>
</cffunction>


<cffunction name="insertProduct " access="public" returntype="string">
  
  <cfargument name="productId" required="Yes" type="string">

  <cftry>
    <cfquery datasource="#this.dsn#">
     INSERT INTO
     VALUES ()
    </cfquery>

   <cfcatch type="Any">
    <cfthrow errorcode="001" message="Error in method insertProduct :<br>#CFCATCH.Message#">
   </cfcatch>
  </cftry>

  <cfreturn arguments.productId>
</cffunction>


<cffunction name="updateProduct" access="public" returntype="string">
  
  <cfargument name="productId" required="Yes" type="string">
  <cfargument name="label" required="Yes" type="string">

  <cftry>
   <cfquery datasource="#this.dsn#">
    UPDATE

    SET  label = '#arguments.label#',
    WHERE productd = '#arguments.productId#'
   </cfquery>

   <cfcatch type="Any">
    <cfthrow errorcode="002" message="Error in method updateProduct:<br>#CFCATCH.Message#">
   </cfcatch>
  </cftry>

<cfreturn arguments.productId>
</cffunction>
</cfcomponent>

Business Object: ProductManager.cfc

<cfscript>
  this.myProductDAO = CreateObject("component", "#your_cfcroot#.dao.DAOFactory).createDAOFactory("your_dsn", "your_cfcroot").getDAOFactory("MSSQL").getProductDAO()>
</cfscript>


<cffunction access="public" name="createProduct" returntype="product">
  
  <cfargument name="productId" type="string" required="Yes">

  <cfreturn this.myProductDAO.getProductById(productId: arguments.productId)>
</cffunction>
</cfcomponent>

this link explains the pattern at all and was used as reference: http://java.sun.com/blueprints/corej2eepatterns/Patterns/DataAccessObject.html

Of course there are some diferences from one implementation in Java and CFC.

I hope this can help as a starting point.

[]'s

Aldo d'Aquino

----- Original Message -----

From: "Nathan Dintenfass" <[EMAIL PROTECTED]>

To: <[EMAIL PROTECTED]>

Sent: Wednesday, October 15, 2003 5:48 PM

Subject: RE: [CFCDev] Calling another CFC from within a method

> In answer to the original question -- if you are calling methods of the same
> CFC you can call them as local variables. So, you can do things like:
>
>
> <cfcomponent>
> <cffunction name="getStuff">
> <cfreturn "stuff">
> </cffunction>
>
> <cffunction name="getFoo">
> <cfset myStuff = getStuff()>
> </cffunction>
> </cfcomponent>
>
> You can also use CFINVOKE, but you don't need the COMPONENT attribute if
> calling a method of the same CFC.
>
>
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> > Behalf Of Nando
> > Sent: Wednesday, October 15, 2003 5:05 AM
> > To: [EMAIL PROTECTED]
> > Subject: [CFCDev] Calling another CFC from within a method
> >
> >
> > I'm working on my first DAO object and was wondering if there is a
> > recommended practice for calling another cfc from within a method of an
> > object, along the lines of using cfinvoke or CreateObject or ...
> >
> >
>
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Re: [CFCDev] Calling another CFC from within a method

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