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Have you ever had a functionality that was the same across multiple objects or fields, but needed to have it slightly different across each implementation? Join us as we show you how to build Visualforce pages in a more reusable manner. Using practical code examples, we'll be taking a code example from a page that is strongly typed to an object to using (1) a Visualforce Component and Dynamic Visualforce Field Bindings to make the page flexible, (2) Apex Describe methods to detect what type of object is being used, and (3) Custom Settings objects to maintain flexibility across objects. Always keep an eye out for opportunities to reuse old code without having to have multiple copies of code to update each time something changes!
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Get the Most Out of Your CodeMaking Your Apex and Visualforce Reusable
Raleigh Chen, USAA, Sr. Software Developer/Integrator
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Raleigh ChenSenior Software Developer/Integrator Enterprise Decision Support Systems
Primary Problem
VS
What Makes Code Reusable?
Flexibility Genericisation
Case Study ExampleTwo custom fields on two different objects – similar functionality
▪ Campaign• Source System• Subsystem Application
▪ Lead• IT System (IT Source of Lead)• Lead Application (Lead Generation Application)
Campaign – Starting PointVisualforce Page for Campaign
Campaign – Create ComponentGeneric Object Components allow for a level of flexibility/genericisation.
▪ Create new Visualforce Component▪ Replace PageBlock with a Visualforce Component
Tip: The <apex:attribute> tag allows you to pass values/objects from the visualforce page to the component
COMPONENTIZATION
“replacing a Visualforce Page with a Component allowing for more flexibility due to the ability to embed Components in other Pages and pass variables into Components”
Campaign – Add Component ControllerReusable Logic should live in the Generic Component Controller
▪ Create new Component Controller▪ Replace the Attribute Object being passed with a more flexible Object
ID
Tip: The assignTo property in the <apex:attribute> tag allows you to pass values/objects from the Visualforce page directly to the component’s controller
IDEEIFY
“passing an ID instead of an object or fields from an object to ensure portability across any object type”
Campaign – Begin to Genericize ControllerUse GlobalDescribe to allow different Objects
▪ Add describe methods necessary for Generic Use• getGlobalDescribe() – pulls all Object tokens• getDescribe() – pulls Object details• getName() – pulls Object Name• getKeyPrefix() – retrieves the 3 character Object Prefix
▪ Remove Strongly Typed fields from the Visualforce Component
Tip: Using the Dynamic Visualforce Binding Notation “runObject[fieldName]” allows using variables for field names.
DESCRIBESPLOSION
“using a generic ID to determine object metadata such as Object Name, key prefix, etc. without relying on hardcoded values”
DYNAMISUALFORDING
“using Dynamic Visualforce Binding notation to ensure flexibility in your sObject’s field names so that they can be variablized and determined at runtime instead of being hardcoded”
Campaign – Create Custom Setting ObjectCustom Settings allow for faster access to metadata for mappings, settings, environment variables, etc.
▪ Define a new Custom Setting
Tip: Custom Settings prevent developers from having to alter code as it moves from environment to environment
Campaign – Add Campaign Entry to Custom SettingThe entry will map the 3 character Object Prefix to all the Object specific information we need
▪ Define Object and Field Name fields
▪ Set Values for Campaign
METAFIELD METANAMING METADATA
“storing the field names that are needed to refer to an object within another reference object, such as a Custom Setting so that the fields that are used can be changed and new possible objects added without code changes”
Campaign – Finalize ControllerRemove all mention of any specific Objects/Field Names
▪ Utilize Custom Setting to get Object/Field Names based on passed Record ID
Tip: The getInstance() method of a Custom Setting allows for quick retrieval of a row of data based on the Name.
DEPROPERIZE
“ensuring that there is no hardcoded object names or field names (except for the Custom Setting object and fields) to ensure that the component can be used with ANY object”
Lead – Try it out for Lead!Create the same Page for Leads
▪ Add entry in Custom Settings for Lead
▪ Add Leads Visualforce Page
ReviewVisualforce Components
▪ <c:component_name attribute_name=“{!value}” />▪ <apex:attribute name="objID" description="The object ID" required="true" type="String" assignTo="{!
objectID}“
Dynamic Visualforce Field Bindings▪ <apex:inputField value="{!object_name[field_name_variable]}" />
Describe Functions▪ getGlobalDescribe()▪ getDescribe()▪ getName()▪ getKeyPrefix()
Review (cont.)Custom Settings
▪ Definition/Usage▪ Custom_Setting_Object_Name.getInstance(rowName)▪ Custom_Setting_Object_Name.getAll()
Raleigh Chen
Sr. Software Developer/Integrator,
USAA
Chatter ChallengeOn Chatter, Submit an example of this type of genericisation using the new Fieldset.
Winner gets a gold star.
