The Silver Lining

Lessons & Learnings from a salesforce certified technical architect.

Archive for June 8th, 2009

Instantiating an empty list of SObjects

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You’re building a dynamic Apex class so general you’re thinking about promoting it to colonel. You’ve slogged through the Salesforce documentation on the topic, a feat in itself, but are having issues instantiating an empty list of SObjects to be processed in some way.

If you attempt to do this in the seemingly Salesforce manner i.e.

List<SObject> sobjects = new List<SObject>();

You will receive the following error: Compile error: Only concrete SObject lists can be created

This can be rather frustrating as this type of data structure is one of the more commonly used. There are however 3 workarounds, one slightly more elegant than the rest.

NB myObject is a SObject.

List<SObject> sobjects = Database.query('select id from ' + myObject.getSObjectType() +' where id=null');
String searchquery='FIND\'xxx\'IN ALL FIELDS RETURNING '+ myObject.getSObjectType() +'(name)';
List<List<SObject> searchList=search.query(searchquery);
List<SObject> sobjects = searchlist[0];

or finally you could use a wrapper class (I’m a huge fan of wrapper classes on this platform)

List sobjects = new List();

public class myObject{

sObject obj {get; set;}

public myObject(sObject obj){
this.obj = obj;

Gratefully this is not a problem you will encouter often, but it is a complex area that can be further complicated by workarounds. But what doesn’t kill you (usually) makes you stronger.

Written by Wes

June 8, 2009 at 12:13 pm

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