[SOLR-5701] Allow DocTransformer to add arbitrary fields

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 4.9, 6.0
• Component/s: search
• Labels: search
• Assignee: Unassigned
• Reporter: jefferyyuan
• Created: 06/Feb/14 03:18
• Updated: 05/Oct/16 22:18

Description

DocTransformer is very powerful, and allow us to add/remove or update fields before returning.

One limit we don't like is that it can only add one field, and the field name must be [transformer_name].

We may want to add multiple fields in one DocTransformer.

One possible solution is to add method getFieldNames into DocTransformer.
public abstract class DocTransformer{
public void List<String> getFieldNames()

{ return null; }

}

Then in SolrReturnFields.add(String, NamedList<String>, DocTransformers, SolrQueryRequest)

Change augmenters.addTransformer( factory.create(disp, augmenterParams, req) ); like below:
DocTransformer docTransfomer = factory.create(disp, augmenterParams, req);
SolrReturnFields.add(docTransfomer);

then read fi3eldnames: docTransfomer.getFieldNames(); add them into SolrReturnFields.

DocTransfomer implementation would add all fields via doc.addField.