System.VisualforceException: Record set cannot be empty

Question

I'm getting this error everytime I'm assigning a non empty list of sObject to a standardsetcontroller

list<sObject> listSearchArticles = someOtherMethod(); // someOtherMethod returns a list of sObjects
if(listSearchArticles.size() > 0 ){
    this.setCon = new ApexPages.StandardSetController( listSearchArticles );
    this.setCon.setpageNumber(1);
    this.setCon.setPageSize(25);
} 

Answer 1

This is a a small curveball, he must just be constructed with concrete list type.

Instead of:

new ApexPages.StandardSetController(new List<SObject>());
//System.VisualforceException: Record set cannot be empty

Try this:

new ApexPages.StandardSetController(new List<Document>());
//ok!

Same goes if you have an empty query result set. Cast the collection before constructing.

Answer 2

You could add a null check before assigning the list to your standardset controller. What you are doing currently is size check. Try this

list<sObject> listSearchArticles = someOtherMethod(); // someOtherMethod returns a list of sObjects
if(listSearchArticles != NULL && listSearchArticles.size() > 0 ){
    this.setCon = new ApexPages.StandardSetController( listSearchArticles );
    this.setCon.setpageNumber(1);
    this.setCon.setPageSize(25);
}
else {
    this.setCon = new ApexPages.StandardSetController(new List<sObject>());
}

If the listSearchArticles is null or its size is zero, the standardsetcontroller will be initialized with blank list of sobjects. Otherwise it will be initialized with the list of sobjects.

Hope it helps.