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This chapter is from the book

Sample Application: Validating Timecards

This section applies Apex, SOQL, DML, and triggers to ensure that timecards entered into the Services Manager sample application have a valid assignment. An assignment is a record indicating that a resource is staffed on a project for a certain time period. A consultant can enter a timecard only for a project and time period he or she is authorized to work. Triggers are one way to enforce this rule.

The following subsections cover the process of configuring the Force.com IDE for Apex development, creating the trigger code to implement the timecard validation rule, and writing and running unit tests.

Force.com IDE Setup

Begin by creating the Force.com IDE Project for the Services Manager sample application, if you have not already done so. Select the menu option File, New, Force.com Project. Enter a project name, username, password, and security token of your Development Edition organization and click the Next button and then the Finish button. The Force.com IDE connects to Force.com, downloads the metadata in your organization to your local machine, and displays a new project node in your Navigator view.

Creating the Trigger

Listing 4.42 defines the trigger to validate timecards. It illustrates a best practice for trigger development: Keep the trigger’s code block as small as possible. Place code in a separate class for easier maintenance and to encourage code reuse. Use naming conventions to indicate that the code is invoked from a trigger, such as the Manager suffix on the class name and the handle prefix on the method name.

Listing 4.42 Trigger validateTimecard

trigger validateTimecard on Timecard__c(before insert, before update) {
  TimecardManager.handleTimecardChange(Trigger.old, Trigger.new);
}

To create this trigger, select File, New, Apex Trigger. Enter the trigger name, select the object (Timecard__c), enable the two trigger operations (before insert, before update), and click the Finish button. This creates the trigger declaration and adds it to your project. It is now ready to be filled with the Apex code in Listing 4.42. If you save the trigger now, it will fail with a compilation error. This is because the dependent class, TimecardManager, has not yet been defined.

Continue on to creating the class. Select File, New, Apex Class to reveal the New Apex Class Wizard. Enter the class name (TimecardManager), leave the other fields (Version and Template) set to their defaults, and click the Finish button.

Listing 4.43 is the TimecardManager class. It performs the work of validating the timecard on behalf of the trigger. First, it builds a Set of resource Ids referenced in the incoming set of timecards. It uses this Set to query the Assignment object. For each timecard, the assignment List is looped over to look for a match on the time period specified in the timecard. If none is found, an error is added to the offending timecard. This error is ultimately reported to the user or program initiating the timecard transaction.

Listing 4.43 TimecardManager Class

public with sharing class TimecardManager {
  public class TimecardException extends Exception {}
  public static void handleTimecardChange(List<Timecard__c> oldTimecards,
    List<Timecard__c> newTimecards) {
    Set<ID> contactIds = new Set<ID>();
    for (Timecard__c timecard : newTimecards) {
      contactIds.add(timecard.Contact__c);
    }
    List<Assignment__c> assignments = [ select Id, Start_Date__c,
      End_Date__c, Contact__c from Assignment__c
      where Contact__c in :contactIds ];
    if (assignments.size() == 0) {
      throw new TimecardException('No assignments');
    }
    Boolean hasAssignment;
    for (Timecard__c timecard : newTimecards) {
      hasAssignment = false;
      for (Assignment__c assignment : assignments) {
        if (assignment.Contact__c == timecard.Contact__c &&
          timecard.Week_Ending__c - 6 >= assignment.Start_Date__c &&
          timecard.Week_Ending__c <= assignment.End_Date__c) {
            hasAssignment = true;
            break;
        }
      }
      if (!hasAssignment) {
        timecard.addError('No assignment for contact ' +
          timecard.Contact__c + ', week ending ' +
          timecard.Week_Ending__c);
      }
    }
  }
}

Unit Testing

Now that the trigger is developed, you must test it. During development, taking note of the code paths and thinking about how they are best covered by unit tests is a good idea. An even better idea is to write the unit tests as you develop.

To create unit tests for the timecard validation code using the Force.com IDE, follow the same procedure as that for creating an ordinary Apex class. An optional variation on this process is to select the Test Class template from the Create New Apex Class Wizard. This generates skeleton code for a class containing only test methods.

Listing 4.44 contains unit tests for the TimecardManager class. Before each unit test, test data is inserted in a static initializer. The tests cover a simple positive case, a negative case in which no assignments exist for the timecard, a second negative case in which no valid assignments exist for the time period in a timecard, and a batch insert of timecards. The code demonstrates a best practice of placing all unit tests for a class in a separate test class with an intuitive, consistent naming convention. In our example, the TimecardManager class has a test class named TestTimecardManager, the class name prefaced by the word Test.

Listing 4.44 Unit Tests for TimecardManager Class

@isTest
private class TestTimecardManager {
  private static ID contactId, projectId;

  static {
    Contact contact = new Contact(FirstName = 'Nobody', LastName = 'Special');
    insert contact;
    contactId = contact.Id;
    Project__c project = new Project__c(Name = 'Proj1');
    insert project;
    projectId = project.Id;
  }

  @isTest static void positiveTest() {
    Date weekEnding = Date.valueOf('2015-04-11');
    insert new Assignment__c(Project__c = projectId,
      Start_Date__c =  weekEnding - 6, End_Date__c = weekEnding,
      Contact__c = contactId);
    insert new Timecard__c(Project__c = projectId,
      Week_Ending__c = weekEnding, Contact__c = contactId);
  }

  @isTest static void testNoAssignments() {
    Timecard__c timecard = new Timecard__c(Project__c = projectId,
      Week_Ending__c = Date.valueOf('2015-04-11'),
      Contact__c = contactId);
    try {
      insert timecard;
    } catch (DmlException e) {
      System.assert(e.getMessage().indexOf('No assignments') > 0);
      return;
    }
    System.assert(false);
  }

  @isTest static void testNoValidAssignments() {
    Date weekEnding = Date.valueOf('2015-04-04');
    insert new Assignment__c(Project__c = projectId,
      Start_Date__c = weekEnding - 6, End_Date__c = weekEnding,
      Contact__c = contactId);
    try {
      insert new Timecard__c(Project__c = projectId,
      Week_Ending__c = Date.today(), Contact__c = contactId);
    } catch (DmlException e) {
      System.assert(e.getMessage().indexOf('No assignment for contact') > 0);
      return;
    }
    System.assert(false);
  }

  @isTest static void testBatch() {
    Date weekEnding = Date.valueOf('2015-04-11');
    insert new Assignment__c(Project__c = projectId,
      Start_Date__c =  weekEnding - 6, End_Date__c = weekEnding,
      Contact__c = contactId);
    List<Timecard__c> timecards = new List<Timecard__c>();
    for (Integer i=0; i<200; i++) {
      timecards.add(new Timecard__c(Project__c = projectId,
        Week_Ending__c = weekEnding, Contact__c = contactId));
    }
    insert timecards;
  }
}

After saving the code in the unit test class, run it by right-clicking in the editor and selecting Force.com, Run Tests. After a few seconds, you should see the Apex Test Runner view with a green check box indicating that all tests passed, as shown in Figure 4.10. Expand the results node to see 100% test coverage of the TimecardManager, and scroll through the debug log to examine performance information and resource consumption for each of the tests.

Figure 4.10

Figure 4.10 Viewing test results

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