public class EditCases {
    List<Case> cases;
    String headerMessage;
    Boolean canEdit = true;
    
    public EditCases() { 
        cases = getcases();+
        headerMessage = getHeaderMessage();
        canEdit = getCanEdit();         
    }   

    public List<Case> getCases() {
        if (cases == null) {
            cases = [
                select Id, CaseNumber, Priority, Status, Subject, 
                    Account.Name, CreatedDate
                from Case
                where Status <> 'Closed' and Priority = 'High'
                order by CaseNumber];
                
            return cases;
        }
        else {
            return cases;
        }
    }

    public String getHeaderMessage() {
         String message = '';
         if (cases.size() == 0) {
             message = 'There are no cases to edit.';
             canEdit = false;
         }    
         else {
             canEdit = true;
         }
         return message;      
    }
   
    public Boolean getCanEdit() {
        return canEdit;
    }
    
        // Action that is executed if Save button is clicked
    public PageReference save() {
            // Return to Cases tab page after editing
        PageReference returnPage = new PageReference('/500/o');
        
            // Save all changes
        update cases;

        return returnPage; 
    }
    
        // Action that is executed if Cancel button is clicked.
    public PageReference cancel() {
            // Return to Cases tab page after editing    
        PageReference returnPage = new PageReference('/500/o');
        return returnPage;
    }
    
    public static testMethod void tesEditCases() {
            // Create the necessary records to test automatic order creation
            // Create a case
            // This assumes that the pick list values used exist for
            //   -  Priority (High)
            //   -  Status (New)
            //   -  Origin (Phone)
        Case testCase = new Case(
            Priority = 'High',
            Subject = 'Test Subject',
            Status = 'New',
            Origin = 'Phone');
        insert testCase;
        
             //**************************
            // Test EditCases controller
            //**************************           
        PageReference pageRef = Page.EditCases;
        Test.setCurrentPage(pageRef);
        
            // Create an instance of the controller
        EditCases editCasesController = new EditCases();
        
            // Get the list of cases from the controller
        List<Case> casesToEdit = editCasesController.getCases();
            
            // Verify that there is at least one case to edit
        system.assertEquals(casesToEdit.size() > 0, true);
        
            // Retrieve the header message
        String editCasesMessage = editCasesController.getHeaderMessage();
        
            // Verify that the header message is blank
        system.assertEquals(editCasesMessage, '');

            // Check the Cancel action
        String canceleditCasesPage = editCasesController.cancel().getUrl();
        
            // Check the save action
        String editCasesPage = editCasesController.save().getUrl();
    }   
}