Picklist using Dynamic Apex

Question

How to display dependent pick-list fields and their values using dynamic apex in visualforce page.

I need to have multiselect hence i am using the below code -

public List<SelectOption> getDept()
    {
        List<SelectOption> options = new List<SelectOption>();
        Schema.DescribeFieldResult departfield =  Activity_Tracker__c.Category__c.getDescribe();
        List<Schema.PicklistEntry> picklist = departfield.getPicklistValues();
        for( Schema.PicklistEntry f : picklist){      
        options.add(new SelectOption(f.getLabel(), f.getValue()));
        }    
        return options;
    }



public List<SelectOption> getCustb()
    {
        List<SelectOption> options = new List<SelectOption>();
        Schema.DescribeFieldResult departfield =  Activity_Tracker__c.SubCust__c.getDescribe();
        List<Schema.PicklistEntry> picklist = departfield.getPicklistValues();
        for( Schema.PicklistEntry f : picklist){      
        options.add(new SelectOption(f.getLabel(), f.getValue()));
        }    
        return options;
    }

Can u please check how to make it dependent.

Answer 1

If you have defined field dependency in the backend, you can get it in page without much coding effort by simply using . Please check below link, https://www.salesforce.com/docs/developer/pages/Content/pages_quick_start_dependent_picklists.htm

Answer 2

I am assuming you are not using the out-of-the-box dependent picklist here. You can modify your existing code like this.

public String selectedValue{get;set;}

public List<SelectOption> getCustb()
    {
        List<SelectOption> options = new List<SelectOption>();
        Schema.DescribeFieldResult departfield =  Activity_Tracker__c.SubCust__c.getDescribe();
        List<Schema.PicklistEntry> picklist = departfield.getPicklistValues();
        for( Schema.PicklistEntry f : picklist){ 
        switch(selectedValue)
        {
         case 'Fruit': {if(f.getValue()=='Mango')
                 options.add(new SelectOption(f.getLabel(), f.getValue())); 
                       }
        case 'Cars': {if(f.getValue()=='Toyota')
                 options.add(new SelectOption(f.getLabel(), f.getValue())); 
                       }
        }

        }    
        return options;
    }

Visualforce:

<apex:selectList value={!selectedValue} size="1" rerender="dependant">
<apex:selectOptions value={!Dept}/></apex:selectList>

<apex:selectList id="dependant" value={!selectedValue} size="3">
<apex:selectOptions value={!Custb}/></apex:selectList>

This trick will work for small picklists where its possible to hardcode. If its a large list, you can prefix a number in all the options to map them with the master picklist. Example: 1Fruit -- 1Mango, 1Apple then 2Cars -- 2Toyota, 2Audi and filter using the prefix number inside the above for loop.

All said and done, I would suggest you to go for Dependent Picklist here, with almost zero code, its much simple, easy and reliable.