Ranking search results using multiple fields in PostgreSQL fulltext search

Hi,

is there a way to rank the search results based on multiple fields in postgreSQL?

For example,

i have title, abstract, summary, body as fields/columns in my database. When user searches on title, i want to rank the results based on title field as well as summary field, where importance(summary) > importance(title). But the results should be exactly matching the terms in "title" rather than "title" OR "summary"