User Log-In

Next on the list of major application functions is the user log-in process (Figure II-3.7). To accomplish this, the teams will utilize the new ColdFusion MX <CFLOGIN> authentication scheme and Flash Remoting's ability to natively communicate with it. The Vshift ColdFusion team has placed a <CFLOGIN> tag in the Application.cfm, to ensure that the expenseapp.cfc run the authentication scheme before any of the component functions can be accessed.

Figure II-3.7. The movie clip form for the log-in process has all of the objects necessary to log-in to the application.

 <cflogin> <cfifIsDefined("CFLOGIN")> <cfqueryname="getuser"datasource="expensedb">  SELECTid,access  FROMusers  WHERE(username='#CFLOGIN.name#')   AND(password='#CFLOGIN.password#') </cfquery>  <cfifgetuser.recordcountgt0>  <cfifgetuser.accesseq2>   <cfloginusername="#CFLOGIN.name#" password="#CFLOGIN.password#" roles="admin">  <cfelse>   <cfloginusername="#CFLOGIN.name#" password="#CFLOGIN.password#" roles="user">  </cfif> </cfif> </cfif> </cflogin> 

instant message

The ColdFusion MX <CFLOGIN> tag is the basis of the new ColdFusion authentication methodology. The tag works with <CFLOGINUSER> and <CFLOGOUT>. Flash Remoting can communi cate with these tags via the setCredentials method of the NetConnection object. <CFLOGIN> utilizes a new variable scope, introduced in ColdFusion MX, called CFLOGIN, which stores the log-in attributes throughout the life of the application.

When this code is placed in the Application.cfm, ColdFusion will be constantly checking for the CFLOGIN attributes until the Flash application sets them. If the log-in attributes are found, the function then tries to find the given user ID and password in the database. If it finds a valid user ID and password in the database, <CFLOGINUSER> authenticates the user and password, and sets their roles in the CFLOGIN scope.

To send the user ID and password from the Flash movie, setCredentials will be used.

 gatewayConnection.setCredentials("usernameField.text"," passwordField.text"); 

Once the user is authenticated in the system, ColdFusion can leverage the ROLES attribute of the <CFFUNCTION> tag. The ROLES attribute is a comma-delimited list of user roles that are allowed to run the function.

 <cffunctionname="myfunction"access="remote"roles="admin"> <!---Ionlyruniftheuserisauthenticatedasanadmin--> </cffunction> 

The ColdFusion team has also created a CFC function called "logout" that will simply call the <CFLOGOUT> command. This removes the user from the CFLOGIN variable scope, thus forcing ColdFusion to ask for a user ID and password again.

instant message

A role can be any string identifier you feel best represents the way the role will be used. Typical roles are user, admin, and superuser, though they can be anything that makes sense for your application.

 <cffunctionname="logout"access="remote">  <cflogout> </cffunction>