Changes between Initial Version and Version 1 of Training/Section05

Timestamp:

12/29/09 20:56:22 (16 years ago)

Author:

cfgrok (IP: 64.30.223.5)

Comment:

Adding new training section

Training/Section05

@@ +1 @@
+[[TOC(heading=Training Section Contents, Training*)]]
+
+= Section 5: Mother's Little Helper =
+
+Part of a quality design is in not repeating the prescription of algorithms. Sure we can encapsulate our algorithm in a User Defined Function (UDF), but in a Model-Glue world, where do UDFs go?
+
+Model-Glue 3 introduces the concept of helpers. Helpers are libraries of user defined functions. By placing these files in the proper location, Model-Glue 3 will automatically load them and make them accessible via the new helpers scope, available to both controller and view files. Let's implement a helper in our application.
+
+ 1. Open /PlantOMatic/config/ColdSpring.xml, find the definition for modelglue.modelGlueConfiguration and ensure you have a helper mapping pointing to /PlantOMatic/helpers:
+
+{{{
+
+<property name="helperMappings"><value>/PlantOMatic/helpers</value></property>
+
+}}}
+
+ 2. Create a new file called date.cfm inside /PlantOMatic/helpers 
+ 3. Place the following function inside /PlantOMatic/helpers/date.cfm 
+
+{{{
+
+<cfscript>
+/*
+* Calculates the number of business days between 2 dates.
+* @param date1 First date. (Required)
+* @param date2 Second date. (Required)
+* @return Returns a number.
+* @author Harry Goldman (harry@icn.net)
+* @version 1, April 10, 2008
+*/
+
+function businessDaysBetween( date1, date2 ) {
+    var numberOfDays = 0;
+    
+    while ( date1 LT date2 ) {
+        date1 = dateAdd( "d", 1, date1 );
+        if ( dayOfWeek( date1 ) GTE 2 AND dayOfWeek( date1 ) LTE 6 )
+            numberOfDays = incrementValue( numberOfDays );
+    }
+    return numberOfDays;
+}
+</cfscript>
+
+}}}
+
+ 4. Open the file /PlantOMatic/views/List.Shipment.cfm and change the following line:
+
+{{{
+
+<td>#dateFormat( CreateDate, "short" )#</td>
+
+}}}
+
+    To call our new UDF from the helpers scope:
+
+{{{
+
+<td>#dateFormat( CreateDate, "short" )#  #helpers.date.businessDaysBetween( CreateDate, now() )# (Business days ago)</td>
+
+}}}
+
+
+ 5. Now, click the Home navigation element again to run the Saved Shipments screen and see the new helper in action:
+
+[[Image(training05-1.png, nolink)]][[BR]]
+'' Date displayed with helper function ''
+
+Helpers are a helpful (''editors note: remove lame pun'') way to organize your User Defined Functions and share them across views and controllers. For more information on Model-Glue Helpers, visit the following documentation:
+
+
+[http://docs.model-glue.com/wiki/HowTos/HowToUseHelpers How To Use Helpers]
+
+----
+
+Back: [wiki:Training/Section04 Training Section 4: Request Formats Are Your Friend]
+
+Next: [wiki:Training/Section06 Training Section 6: Flow and Dependencies]