Values to fetch from Custom settings and display it in a picklist in visualforce

Question

I am a newbie,so i dont know how to work around with custom settings.In the requirement there is a custom setting object called OppCountryRegionMapping__c.In this object there are 2 fields,region__c and country__c.Below is the screenshots of custom settings.

When i click on manage there are records,which have records.

When i select particular record,it will have the values for Name,region and country.

Like

 Name-->AustraliaAsia
 Region-->Asia
 Country-->Australia

I have to develop a page where region and country should be picklist.The region should show all distinct regions and when i select particular region from the picklist the corresponding countries should be displayed in the country picklist.

I have tried with the following visualforce and apex code.

Visualforce

      <apex:page Controller="testing_custom">
       <apex:form >
         <apex:selectList label="Region" value="{!region}" size="1" multiselect="false">
          <apex:selectOptions value="{!regionsSelectList}"/>
         </apex:selectList>
     <apex:selectList label="Country" value="{!country}" size="1" multiselect="false">
          <apex:selectOptions value="{!CountriesSelectList}}"/>
         </apex:selectList>
       </apex:form>
      </apex:page>

Apex

   public class testing_custom
   {
       public String region{get;set; }
       public String country{get;set;}

    //For getting region list from custom settings object
    public List<SelectOption> getregionsSelectList(){ 
    List<SelectOption> options = new List<SelectOption>(); 
    set<String> setUniqueRegion = new set<String>();
    for(OppCountryRegionMapping__c setting :       OppCountryRegionMapping__c.getAll().values()){
    if(!setUniqueRegion.contains(setting.Region__c)){
        options.add(new SelectOption(setting.name, setting.Region__c));
        setUniqueRegion.add(setting.Region__c);       
    }
  }    

     return options;
 }

  //For getting country list based on selected region from custom settings object
   public List<SelectOption>  getCountriesSelectList() {

    List<SelectOption> options = new List<SelectOption>();

     for(OppCountryRegionMapping__c setting : OppCountryRegionMapping__c.getAll().values()) {

        if (setting.Region__c== this.region) {
         options.add(new SelectOption(setting.name,setting.Country__c));

        }

    }
      system.debug('*****selected value inside'+options);
      return options;
  }

This is getting duplicate values of region also,

i tried placing the values in the set.But it will not work.How have to proceed with this.Help me.

Thanks

Answer 1

If you removed one line i.e. options.add(new SelectOption(setting.name, setting.Region__c)); and still getting duplicates values.

So Issue with your custom setting record..

Not sure with your business logic. But As you asked for solving duplicate region issue. Then

You can resolve your duplicate region issue with salesforce collection set unique feature.

Do like below

 public class testing_custom
   {
       public String selectedValue{get;set; }

       public List<SelectOption> getMyOptions(){ 
       List<SelectOption> options = new List<SelectOption>(); 
       set<String> setUniqueRegion = new set<String>();
      for(OppCountryRegionMapping__c setting : OppCountryRegionMapping__c.getAll().values()){
        if(!setUniqueRegion.contains(setting.Region__c)){}
            options.add(new SelectOption(setting.name, setting.Region__c));
            setUniqueRegion.add(setting.Region__c);       
        }
      }    

      return options;
  }
}

Answer 2

I saw that you put the same code in loop body in twice.

for(OppCountryRegionMapping__c setting : OppCountryRegionMapping__c.getAll().values()){
    options.add(new SelectOption(setting.name, setting.Region__c));
    options.add(new SelectOption(setting.name, setting.Region__c));
}