Today, we can write a custom Field using custom IndexFieldType, but when the DefaultIndexingChain converts IndexFieldType to FieldInfo <https://github.com/apache/lucene-solr/blob/master/lucene/core/src/java/org/apache/lucene/index/DefaultIndexingChain.java#L662>, only few key informations such as indexing options and doc value type are retained. The Codec gets the FieldInfo <https://github.com/apache/lucene-solr/blob/master/lucene/core/src/java/org/apache/lucene/codecs/DocValuesConsumer.java#L90>, but not the type details.
FieldInfo has support for 'attributes' <https://github.com/apache/lucene-solr/blob/master/lucene/core/src/java/org/apache/lucene/index/FieldInfo.java#L47> and it would be great if we can add 'attributes' to IndexFieldType also and copy it to FieldInfo's 'attribute'. If we can at-least add the 'field type' to the FieldInfo attribute, that should suffice, but I felt adding attributes to IndexFieldType would be more appropriate. This would allow someone to write a custom codec (extending docvalueformat for example) for only the 'special field' that he wants and delegate the rest of the fields to the default codec. Let me know if there are other alternatives or if I should create an issue for this. Thanks, Murali
