How to sort the Contact ASC and group the search result by the most number of matched result

Question

I have 3 lookup relationship with contact and I created a List for each lookup. For every list, I put it on a Set of IDs which is being used in the contact list in order to related the lookup on the contact. I put everything on a wrapper class so that every skill, training or cert will check if the id is matched on the contact Id.

public class pageFilter {

    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;}             
}

pageFilterList = new List<pageFilter>();

for(Contact cons : contList ){
        pgf = new pageFilter();                   
        pgf.employee = cons;

        // SKILLS
        if(!String.isEmpty(wrapFilter1.skillName1) || !String.isEmpty(wrapFilter2.skillName2) || !String.isEmpty(wrapFilter3.skillName3) || !String.isEmpty(wrapFilter4.skillName4) || !String.isEmpty(wrapFilter5.skillName5) ) {  

            List<Employee_Skills__c> empSkills = new List<Employee_Skills__c>();

            for(Employee_Skills__c empSkill : skillList ){
                if(cons.Id == empSkill.Employee_Id__c){
                    empSkills.add(empSkill);                       
                } 
            }
            pgf.empSkillList = empSkills;
        }
        pageFilterList.add(pgf);
}

We have 5 filters, each of the filters can search for skill, training or certification.

How to sort the Contact ASC and group the search result by the most number of matched result.

Answer 1

As Santanu commented, if you implement the Comparable interface on pageFilter then you can use Apex to sort by whatever criteria you want.

Here I only check to total count of all skills, training and certifications.

public 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;} 
    public integer totalCount {
        get {
            // Might need to check for nulls here...
            return empSkillList.size() + empTrainingList.size() + empCertificationList.size();
        }
    }             

    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;
        }

    }
}

Then you just need to apply the sorting:

pageFilterList.sort();

In most cases where I've implemented Comparable I'll have a SortingBy enum and SortAsc boolean that I can use to control what controls the sort ordering and if the direction should be ascending or descending.