Load an Apex class structure dynamically

Question

Looking for a way to dynamically set a class structures fields by list or map of the string version. I know we can do this with Objects. Here is kinda of what I am wanting to do. This is a simple model and it works when working with SObjects

public class myClass{
  public string name;
  public Date  currentDate;
  public string email;
}


public myClass loadValues{
   Map<string, string> structMappedValues  = new Map<string,string>();
   structMappedValues.put('name', 'new name');
   structMappedValues.put('currentDate', '2015-01-01');

   myClass mc = new myClass();
   for(String field : structMappedValues){
      mc.put(field, structMappedValues.get(field));
   }
   return mc;
}

Answer 1

Apex does not support field level reflection so there is no convenient API to populate named fields of a class.

However, for specific cases you can make use of the Apex's support of JSON serialization/deserialization. You can serialize your map and deserialize the JSON string into an instance of myClass:

myClass mc = (myClass) JSON.deserialize(JSON.serialize(structMappedValues), myClass.class);

providing the field names match and the data formats such as the date string is in the format that the deserialization expects.

Answer 2

Thanks to Keith C. I have my solution for the overall aspect of what I was doing. Here is the almost completed class. I leave some for you to do but this covers a large portion. Hope it helps others out there.

This class allows for a field Mapping reference between a SObject and a class structure and then loads the class structure based on data from the SObject, can easily be done the other way also with some modification.

public class myClass{
  public string name;
  public Date  currentDate;
  public string email;
}

public Set<String> getAttributes() // found example here on stackExchange
{
     myClass m = new myClass();
     // Serialize out Ojbect into JSON
     String s = JSON.serialize(m);
     // Deserialize it back into a key/value map
     Map<String,Object> obj = (Map<String,Object) JSON.desializeUntyped(m);
     // Return a Set of those fields present on our object
     return obj.keyset().clone();
}

// build an sObject to myClass field name map
// Acutal not shown sorry 
{  
   Map<String,String> fieldMap  = new Map<String,String>();
   fieldMap.put(sObjectFieldName, structureFieldName);
   // this puts sObject fields and maps them to myClass Structure fields
}

public myClass loadValues{

   // Get Data from SObject based on fieldMap
   // Actual Not shown sorry
   List<SObject> sObjects = [SELECT id, name FROM SObject];
   for(SObject s : SObjects){
        Map<string, string> structMappedValues  = new Map<string,string>();

        myClass mc = new myClass();
        for(String field : fieldMap  ){               
           structMappedValues.put(fieldMap.get(field), (string)s.get(field))
        }
        //Thanks Keith C - convert mapped field and data to class struct
        mc = (myClass) JSON.deserialize(JSON.serialize(structMappedValues),myClass.class);
   }
   return mc;
}