Sorting of fields of custom object using comparable in a wrapper

Question

I have a wrapper class which is sorted by the totalCount of the size of the three list (empSkillList, empTrainingList, and empCertificationList). Can I sort it also by the fields inside the list of the custom object? If yes, how to do so? Or will I convert it first to a list of string so I can compare it?

global class pageFilter implements comparable {

    public Contact employee{get;set;}
    public List<Employee_Skills__c> empSkillList{get;set;}
    public List<Employee_Training__c> empTrainingList{get;set;}
    public List<Employee_Certification__c> empCertificationList{get;set;}

    //related list of skill, training and Cert
    public List<Employee_Skills__c> relatedSkillList{get;set;}
    public List<Employee_Training__c> relatedTrainingList{get;set;}
    public List<Employee_Certification__c> relatedCertificationList{get;set;}               

    public integer totalCount { 
       get {
            // Grouped based on the number of matched filter
            if (empSkillList != null && empTrainingList == null && empCertificationList == null) {
                return empSkillList.size();    
            }

            if (empTrainingList != null && empSkillList == null && empCertificationList == null) {
                return empTrainingList.size();    
            }                 

            if (empCertificationList != null && empSkillList == null && empTrainingList == null) {
                return empCertificationList.size();
            }

            if (empSkillList != null && empTrainingList != null && empCertificationList == null ) {
                return empSkillList.size() + empTrainingList.size();
            }

            if (empSkillList != null && empTrainingList == null && empCertificationList != null ) {
                return empSkillList.size() + empCertificationList.size();
            }                        

            if (empSkillList == null && empTrainingList != null && empCertificationList != null) {
                return empTrainingList.size() + empCertificationList.size();
            }

            if (empSkillList != null && empTrainingList != null && empCertificationList != null ) {
                return empSkillList.size() + empTrainingList.size() + empCertificationList.size();                   
            }
            return  0; 

        }                      
    } 

    public Integer compareTo(Object compareTo) {
    pageFilter compareToFilter = (pageFilter)compareTo;

        if(this.totalCount < compareToFilter.totalCount) {
            return 1;
        } else if(this.totalCount > compareToFilter.totalCount) {
            return -1;
        } else {
            // You could check further criteria when counts are the same.
            return 0;
        }
    }

}

How can I access the fields in the list and compare each record inside the list?

Integer compareFields(pageFilter that){ 
    if(this.empSkillList.Skill_ID__r.Name > that.empSkillList.Skill_ID__r.Name){ 
        return 1; } 
//so on and so forth 
} 

This is the sample code that we are analyzing but since we cannot access the certain record in the list, this code will not work.

Answer 1

Yes, you can add fields to compare when the child count is the same:

public Integer compareTo(Object instance)
{
    PageFilter that = (PageFilter)instance;
    if (that.totalCount == this.totalCount)
    {
        return compareFields(that);
    }
    return that.totalCount - this.totalCount;
    // or simply:
    // return (that.totalCount == this.totalCount) ?
    //    compareFields(that) : that.totalCount - this.totalCount;
}
Integer compareFields(PageFilter that)
{
    // sort on text fields instead
}

Note also that you can greatly simplify the total count:

public Integer totalCount
{
    get
    {
        Integer skillCount = (empSkillList == null) ? 0 : empSkillList.size();
        Integer trainingCount = (empTrainingList == null) ? 0 : empTrainingList.size();
        Integer certificationCount = (empCertificationList == null) ? 0 : empCertificationList.size();
        return skillCount + trainingCount + certificationCount;
    }
}

Much less complicated to test and maintain.