Building Applications with Force.com and VisualForce (DEV401)（五）：Application Essential: Introducing Business Logic

Dev 401-005 Application Essential: Introducing Business Logic

Module Agenda
1.Custom object Queues
2.Workflow
3.Formula Fields
4.Roll up Summary Fields
5.Validation Rules.

Module Overview
1.Create a custom object queue.
2.Create an event-based workflow with a field update action.
3.Create a custom formula operating on fields from one object.
4.Create a cross-object formula.
5.Create a roll-up summary field.
6.Create validation rules.

Custom Object Queues
1.Queues allow groups of users to manage a shared workload more effectively.
2.A queue is a location where records can be routed to await processing by a group member.
3.Records remain in the queue util a user accepts them from processing or they are transferred to another queue.
4.Developers can specify the set of objects that are supported by each queue,as well as the set of users that are allowed 
to retrieve records from the queue.
5.Any member of a queue has the same access to all records in the queue that an owner would have.

Exercise 4-1:Creating Custom Object Queues
1.Goal:
- Create a custom queue for the Recruiting department to hold position and candidate records
2.Scenario:
- Universal Containers wants to use the queue feature to manager the pool of recruiters working with open positions and candidates.
3.Tasks:
- Create a queue for positions and candidates.

Workflow Rules
1.Automate business processes
- Triggered on record write
- Execute Actions
  .Immediately and /or
  .Later(only if records still meets entry criteria)

Workflow Rule Configuration
1.Entry criteria:which records
- Object Type
- Evaluation Criteria
- Rule Criteria
2. Timing:when to excute actions
- Immediately
- Time Dependent
3. Actions:what to do
- Assign Task
- Update Field
- Send Email Alert
- Post Outbound SOAP Message

Custom Formula Fields
1."Smart" Custom fields that can be used to build business-specific calculations using simplle wizards and an Excel-like 
formula language.
2.Supported on standard and custom objects.
3.Can reference standard, custom, or other formula fields.
4.Can reference fields on related objects.

Cross-Object  Formula Fields
1.Cross-object formula fields enable you to incorporate merge fields from multiple objects for calculations and display
2.Create formulas that reference fields on parent or grand parent object(up to 5 levels)
3.Are limited to five unique relationships per object across all formulas and rules for that object.
4.Display fields from related objects on detail pages, list view,reports, etc
6.Use a simple wizard to browse across objects and insert fields in formulas.

Roll-Up Summary Fields
1.Roll-up summary fields are read-only formula field that can display the sum,min,or max value or record count of a field 
in a related list.
- For all custom master-detail relationships.
- For limited standard relationships(Account-Opportunity and Opportunity-Product).
2.There is an option to include all records in the roll-up or just records that meet certain criteria.

 

Validation Rules
1.Validation rules verify that the data a user enters in a record meets the standards you specify before the user can save 
the record.
2.A validation rule can contain a formula or expression that evaluates the date in one or more fields and returns a value 
of True or False.
3.Validation rules also include an error message to display to the user when the rule returns a value of True due to an 
invalid value.
4.Error message can be displayed directly below field or at top of the page.
- Multiple error messages may be displayed at one time.

Validation Rules
1.RecordType Name and ID can be formula merge fields.
2.Standard and custom User merge fields for the current user are also available, allowing user and profile specific 
validation rules.
3.IsChanged(field0 function allows validation to be conditional based on whether a specific field value has changed.
4.PriorValue(field) allows access to previous value of field.
5.IsNew() allows different validation rules for create vs. update actions.

Validation Rules Best Practices
1.Express error message in terms that help the user enter a valid value.
2.Keep error messages relatively short toavoid excessive wrapping.

Exercise 4-6:
Creating Validation Rules
1.Goal:
- Create validation rules to enforce business requirements
2.Scenario:
- Universal Containers wants to ensure that reviewers provide an explanation if they give someone a low score for Cultural
Fit the Review object.
- Additionally, the want reviewers to always provide specific detail if the are recommending someone for hire.
- Finally, UC employees should not be able to save a position record unless the Hiring manager field is filled out.
3.Task:
- Add a validation rule to require that if someone give a candidate a Culture Fit Score of <2 they must include an explanation
- Add a validation rule that requires people to fill in the Reason Recommended box if the check Recommend for Hire
- Add a validation rule that requires that all positions must have a Hiring Manager Field

Module Review 
1.What is the purpose of a Queue?
2.When is workflow triggered?
3.Give an example of cross-object formula that we created during this section.
4.When writing a validation rule, developers must write the error condition formula and the (error message)?
5.What are the tree ways to make a field required?
  Check-box;Validation Rule;Page Layout
6.Where can uses go to find more information on creating formula fields and validation rules?