module Clear::Model::FullTextSearchable
Overview
Full text search plugin offers full integration with tsvector
capabilities of
Postgresql.
It allows you to query models through the text content of one or multiple fields.
The blog example
Let's assume we have a blog and want to implement full text search over title and content:
create_table "posts" do |t|
t.column :title, :string, null: false
t.column :content, :string, null: false
t.full_text_searchable on: [{"title", 'A'}, {"content", 'C'}]
end
This migration will create a 3rd column named full_text_vector
of type tsvector
,
a gin index, a trigger and a function to update automatically this column.
Over the on
keyword, '{"title", 'A'}'
means it allows search of the content of "title", with level of priority (weight) "A", which tells postgres than title content is more meaningful than the article content itself.
Now, let's build some models:
model Post
include Clear::Model
#...
full_text_searchable
end
Post.create!({title: "About poney", content: "Poney are cool"})
Post.create!({title: "About dog and cat", content: "Cat and dog are cool. But not as much as poney"})
Post.create!({title: "You won't believe: She raises her poney like as star!", content: "She's cool because poney are cool"})
Search is now easily done
Post.query.search("poney") # Return all the articles !
Obviously, search call can be chained:
user = User.find! { email == "[email protected]" }
Post.query.from_user(user).search("orm")
Additional parameters
catalog
Select the catalog to use to build the tsquery. By default, pg_catalog.english
is used.
# in your migration:
t.full_text_searchable on: [{"title", 'A'}, {"content", 'C'}], catalog: "pg_catalog.french"
# in your model
full_text_searchable catalog: "pg_catalog.french"
Note: For now, Clear doesn't offers dynamic selection of catalog (for let's say multi-lang service). If your app need this feature, do not hesitate to open an issue.
trigger_name
, function_name
In migration, you can change the name generated for the trigger and the function, using theses two keys.
dest_field
The field created in the database, which will contains your ts vector. Default is full_text_vector
.
# in your migration
t.full_text_searchable on: [{"title", 'A'}, {"content", 'C'}], dest_field: "tsv"
# in your model
full_text_searchable "tsv"
Direct including types
Defined in:
clear/extensions/full_text_searchable/model.crClass Method Summary
-
.to_tsq(text)
Parse client side text and generate string ready to be ingested by PG's
to_tsquery
.
Macro Summary
-
full_text_searchable(through = "full_text_vector", catalog = "pg_catalog.english", scope_name = "search")
Set this model as searchable using tsvector
Class Method Detail
Parse client side text and generate string ready to be ingested by PG's to_tsquery
.
Author note: pg to_tsquery
is awesome but can easily fail to parse.
search
method use then a wrapper text_to_search used to ensure than
request is understood and produce ALWAYS legal string for to_tsquery
This is a good helper then to use with the input of your end-users !
However, this helper can be improved, as it doesn't use all the features of tsvector (parentesis, OR operator etc...)
Macro Detail
Set this model as searchable using tsvector