(pg_search_scope) tsvector_column in associated_against

[joao.a...@gmail.com]

Hello,

I need to implement full text search in my project but noticed there is no support for tsvector columns in associated models. 

I have a somewhat complex associations where the "main" text to be searched is not in the main model.

Anyway, i went ahead and started implementing something in my fork, but would like to know if there are any thoughts on this.

Summary of my changes so far.
Change of pg_search_scope tsvector_column syntax (the old is still supported so no worries):

pg_search_scope :fast_content_search,
                :against => {
                  tsvector_title_tsearch: { weight: 'A', tsvector_column: true }
                },
                :associated_against => {
                  content: {
                    tsvector_content_tsearch: { weight: 'B', tsvector_column: true }
                  }
                },
                using: {
                  tsearch: {
                    dictionary: "english",
                  }
                }

The weight is to show support for applying weight to a tsvector, exclude it if your tsvector column already has weight or it does not need to be used.

Added rails migration (required) to support aggregating tsvectors ( adds a function and an aggregate ).

At the moment I have only implemented (and tested) with the tsearch feature, not sure if it will automatically work with the others but I will take a look when I can.