According to Ransack documentation, there is a possibility to pass custom arguments to a ransacker method:
class Person < ApplicationRecord
ransacker :author_max_title_of_article_where_body_length_between, args: [:parent, :ransacker_args] do |parent, args|
min, max = args
query = <<-SQL
(SELECT MAX(articles.title)
FROM articles
WHERE articles.person_id = people.id
AND CHAR_LENGTH(articles.body) BETWEEN #{min.to_i} AND #{max.to_i}
GROUP BY articles.person_id
)
SQL
Arel.sql(query)
end
end
In the same documentation there is even an example of passing custom arguments:
Person.ransack(
conditions: [{
attributes: {
'0' => {
name: 'author_max_title_of_article_where_body_length_between',
ransacker_args: [10, 100]
}
},
predicate_name: 'cont',
values: ['Ransackers can take arguments']
}]
)
However, there is no documentation on how can I pass that custom arguments from a view, as there appears to be no search_form_for helpers to do that.
Is there a way of passing these arguments through the form, without needing to parse the parameters in the controller to perform the search as pointed in the example?
Related
I use Ruby on Rails and Postgres 9.5.
In the database I have a table called events.
I want to find all events based on particular value in the data field.
events.data has the following possible json value:
{ 'transition' => { 'from' => 'bacon', 'to' => 'ham' } }
How can I build a query that will find an event with data => transition => from bacon?
Assuming that your model is called Event, you can do it like this:
Event.where("data -> 'transition' ->> ? = ?", 'from', 'bacon')
Here is jsonb operators reference.
This query will return all events where data.transition.from is equal to bacon.
To DRY your queries, you can add it to the repository, e.g.:
# app/repositories/event_repository.rb
module EventRepository
extend ActiveSupport::Concern
included do
scope :where_transition, ->(field, value) { where("data -> 'transition' ->> ? = ?", field, value) }
end
end
After that include it in your model:
include EventRepository
Then you can use it like this:
Event.where_transition('from', 'bacon')
Event.where_transition('to', 'ham')
I added the following filter in ActiveAdmin.
filter :roles, as: :select, collection Model::ROLES, multiple: true
but when i choose the filter value to search the roles. it gives me following error
PG::InvalidTextRepresentation: ERROR: malformed array literal: "teacher"LINE 1: ...ted" = $1 AND roles" IN('teacher
DETAIL: Array value must start with "{" or dimension information. ^
Any idea ? How we can search/Filter ARRAY field using AA filters? I'm using Rails 4.2.4,
ruby 2.2.2p95
I came up to a solution slightly different (and inspired by) this one over here: https://stackoverflow.com/a/45728004/1170086
Mine involves some changes (and prevent breaking contains operator in other cases). So, you're going to basically create two initializer files:
This one is for Arel, in order to support #> operator (array's contain operator in PG) for a given table column.
# config/initializers/arel.rb
module Arel
class Nodes::ContainsArray < Arel::Nodes::Binary
def operator
:"#>"
end
end
class Visitors::PostgreSQL
private
def visit_Arel_Nodes_ContainsArray(o, collector)
infix_value o, collector, ' #> '
end
end
module Predications
def contains(other)
Nodes::ContainsArray.new self, Nodes.build_quoted(other, self)
end
end
end
The other file aims to create a new Ransack predicate but I also decided to support the :array type (that's not natively supported in Ransack in terms of predicates).
# config/initializers/ransack.rb
module Ransack
module Nodes
class Value < Node
alias_method :original_cast, :cast
def cast(type)
return Array(value) if type == :array
original_cast(type)
end
end
end
end
Ransack.configure do |config|
config.add_predicate 'contains_array',
arel_predicate: 'contains',
formatter: proc { |v| "{#{v.join(',')}}" },
validator: proc { |v| v.present? },
type: :array
end
And in other to use it. All you need to do is:
User.ransack(roles_contains_array: %i[admin manager])
Or as a filter in ActiveAdmin (which is my case):
ActiveAdmin.register User do
# ...
filter :roles_contains_array, as: :select, collection: User.roles_for_select
# ...
end
I hope it works for you as it worked for me. ;)
You can set up a custom ransacker method to first collect the ids you want returned using a regular postgres search, and then return the results based on those ids:
class User < ApplicationRecord
ransacker :roles,
formatter: proc { |str|
data = where("? = ANY (roles)", str).map(&:id)
data.present? ? data : nil
} do |parent|
parent.table[:id]
end
end
If your filter is a select drop-down, then this should work fine. If you have a free-form text box, then make sure to use the "in" predicate:
filter :roles_in, as: :string
leandroico solutions works well.
But if you add the predicate with this formatter
formatter: proc { |v| "{#{v.join(', ')}}" }, (note the space after the comma)
Then you could use the multiple: true keyword in the filter input and filter by more than one value:
filter :roles_contains_array, as: :select, multiple: true, collection: User.roles_for_select
I used the answer from #leandroico to come up with the below wiki-type approach to doing this.
How to Create Custom SQL Searches for ActiveAdmin (using Arel and Ransack)
In ActiveAdmin, filters are declared in app/admin/model.rb like:
ActiveAdmin.register Model do
filter 'column_name', label: 'column_name', as: :string
end
That will make a searchbox available on the front-end with options to choose between
contains
equals
starts with
ends with
You can even do something like...
filter 'column_name_contains', label: 'column_name', as: :string
...to only have a contains type search available on the front-end.
You can also (after defining some custom methods elsewhere) specify other, non-built-in search methods, like:
filter 'column_name_custom_contains', label: 'column_name', as: :string
The rest of this doc will be about how to define this custom search method, custom_contains
Within config/initializers/arel.rb, define the following:
module Arel
# this example of custom_contains will cast the SQL column as ::text and then do a wildcard-wrapped ILIKE
class Nodes::CustomContains < Arel::Nodes::Binary
def operator
'::text ILIKE'.to_sym
end
end
class Visitors::PostgreSQL
private
def visit_Arel_Nodes_CustomContains(o, collector)
infix_value o, collector, '::text ILIKE '
end
end
module Predications
def custom_contains(column_value)
column_value = self.relation.engine.column_types[self.name.to_s].type_cast_for_database(column_value)
column_value = "%#{self.relation.engine.send(:sanitize_sql_like, column_value)}%" # wrap escaped value with % wildcard
column_value = Nodes.build_quoted(column_value, self)
Nodes::CustomContains.new(self, column_value)
end
end
end
module ActiveRecord::QueryMethods
def custom_contains(predicates)
return none if predicates.length == 0
predicates.map{ |column_name, column_value|
column_value = table.engine.column_types[column_name.to_s].type_cast_for_database(column_value)
column_value = "%#{table.engine.send(:sanitize_sql_like, column_value)}%" # wrap escaped value with % wildcard
column_value = Arel::Nodes.build_quoted(column_value)
where Arel::Nodes::CustomContains.new(table[column_name], column_value)
}.inject(:merge)
end
end
module ActiveRecord::Querying
delegate :custom_contains, :to => :all
end
Within config/initializers/ransack.rb, define the following:
Ransack.configure do |config|
config.add_predicate(
'custom_contains',
arel_predicate: 'custom_contains',
formatter: proc { |v| v.to_s },
validator: proc { |v| v.present? },
type: :string
)
end
The above has accomplished a couple of things:
1) You can use the custom_contains method that was delegate'd to all ActiveRecord models:
puts Model.custom_contains(column_name: 'search for me').to_sql
2) You can use Ransack to search against the Arel predicates that were defined:
puts Model.ransack(column_name_custom_contains: 'search for me').result.to_sql
However, in order to do the below in ActiveAdmin...
filter 'column_name_custom_contains', label: 'column_name', as: :string
...we must add a scope to Model so that there is a method, column_name_custom_contains, on Model
scope_name = "#{column_name}_custom_contains".to_sym
unless Model.methods.include?(scope_name)
Model.scope(
scope_name,
->(value) {
Model.custom_contains({column_name.to_sym => value})
}
)
end
Voila!
I have a model Event that is connected to MongoDB using Mongoid:
class Event
include Mongoid::Document
include Mongoid::Timestamps
field :user_name, type: String
field :action, type: String
field :ip_address, type: String
scope :recent, -> { where(:created_at.gte => 1.month.ago) }
end
Usually when I use ActiveRecord, I can do something like this to group results:
#action_counts = Event.group('action').where(:user_name =>"my_name").recent.count
And I get results with the following format:
{"action_1"=>46, "action_2"=>36, "action_3"=>41, "action_4"=>40, "action_5"=>37}
What is the best way to do the same thing with Mongoid?
Thanks in advance
I think you'll have to use map/reduce to do that. Look at this SO question for more details:
Mongoid Group By or MongoDb group by in rails
Otherwise, you can simply use the group_by method from Enumerable. Less efficient, but it should do the trick unless you have hundreds of thousands documents.
EDIT: Example of using map/reduce in this case
I'm not really familiar with it but by reading the docs and playing around I couldn't reproduce the exact same hash you want but try this:
def self.count_and_group_by_action
map = %Q{
function() {
key = this.action;
value = {count: 1};
emit(key, value);
# emit a new document {"_id" => "action", "value" => {count: 1}}
# for each input document our scope is applied to
}
}
# the idea now is to "flatten" the emitted documents that
# have the same key. Good, but we need to do something with the values
reduce = %Q{
function(key, values) {
var reducedValue = {count: 0};
# we prepare a reducedValue
# we then loop through the values associated to the same key,
# in this case, the 'action' name
values.forEach(function(value) {
reducedValue.count += value.count; # we increment the reducedValue - thx captain obvious
});
# and return the 'reduced' value for that key,
# an 'aggregate' of all the values associated to the same key
return reducedValue;
}
}
self.map_reduce(map, reduce).out(inline: true)
# we apply the map_reduce functions
# inline: true is because we don't need to store the results in a collection
# we just need a hash
end
So when you call:
Event.where(:user_name =>"my_name").recent.count_and_group_by_action
It should return something like:
[{ "_id" => "action1", "value" => { "count" => 20 }}, { "_id" => "action2" , "value" => { "count" => 10 }}]
Disclaimer: I'm no mongodb nor mongoid specialist, I've based my example on what I could find in the referenced SO question and Mongodb/Mongoid documentation online, any suggestion to make this better would be appreciated.
Resources:
http://docs.mongodb.org/manual/core/map-reduce/
http://mongoid.org/en/mongoid/docs/querying.html#map_reduce
Mongoid Group By or MongoDb group by in rails
I'm trying to use passing options in representers gem
I have a decorator:
class ProductDecorator < Representable::Decorator
include Representable::JSON
property :code
property :name
property :store_id, getter: lambda { |opts| opts[:store_id] },
type: Integer
property :url, decorator_scope: true, getter: lambda { |options|
File.join(options.fetch(:site,""), url)
}, type: String
def url
File.join(represented.path ,"p")
end
end
But when I try to pass my options using:
ProductDecorator.new(product).
to_hash(store_id: 1, site: "my_url")
I'm getting the message wrong number of arguments (1 for 0)
I've tried many options, but I could find what's going on.
to_hash method doesn't take arguments that is the reason for error.
I suppose you meant to do something like:
ProductDecorator.new(product).to_json(store_id: 1, site: "my_url")
Or you can also go for:
JSON.parse(ProductDecorator.new(product).
to_json(store_id: 1, site: "my_url")).symbolize_keys
Converting a Rails 2 application to Rails 3, I have to replace the gem searchlogic. Now, using Rails 3.2.8 with the gem Ransack I want to build a search form which uses an existing scope. Example:
class Post < ActiveRecord::Base
scope :year, lambda { |year|
where("posts.date BETWEEN '#{year}-01-01' AND '#{year}-12-31'")
}
end
So far as I know, this can be achieved by defining a custom ransacker. Sadly, I don't find any documentation about this. I tried this in the Postclass:
ransacker :year,
:formatter => proc {|v|
year(v)
}
But this does not work:
Post.ransack(:year_eq => 2012).result.to_sql
=> TypeError: Cannot visit ActiveRecord::Relation
I tried some variations of the ransacker declaration, but none of them work. I Need some help...
UPDATE: The scope above is just on example. I'm looking for a way to use every single existing scope within Ransack. In MetaSearch, the predecessor of Ransack, there is a feature called search_methods for using scopes. Ransack has no support for this out of the box yet.
ransack supports it out of the box after merging https://github.com/activerecord-hackery/ransack/pull/390 . you should declare ransakable_scopes method to add scopes visible for ransack.
From manual
Continuing on from the preceding section, searching by scopes requires defining a whitelist of ransackable_scopes on the model class. The whitelist should be an array of symbols. By default, all class methods (e.g. scopes) are ignored. Scopes will be applied for matching true values, or for given values if the scope accepts a value:
class Employee < ActiveRecord::Base
scope :activated, ->(boolean = true) { where(active: boolean) }
scope :salary_gt, ->(amount) { where('salary > ?', amount) }
# Scopes are just syntactical sugar for class methods, which may also be used:
def self.hired_since(date)
where('start_date >= ?', date)
end
private
def self.ransackable_scopes(auth_object = nil)
if auth_object.try(:admin?)
# allow admin users access to all three methods
%i(activated hired_since salary_gt)
else
# allow other users to search on `activated` and `hired_since` only
%i(activated hired_since)
end
end
end
Employee.ransack({ activated: true, hired_since: '2013-01-01' })
Employee.ransack({ salary_gt: 100_000 }, { auth_object: current_user })
Ransack let's you create custom predicates for this, unfortunately the documentation leaves room for improvement however checkout: https://github.com/ernie/ransack/wiki/Custom-Predicates
Also I believe the problem you're trying to tackle is up on their issue tracker. There's a good discussion going on there: https://github.com/ernie/ransack/issues/34
I wrote a gem called siphon which helps you translate parameters into activerelation scopes. Combining it with ransack can achieves this.
You can read full explanation here. Meanwhile here's the gist of it
The View
= form_for #product_search, url: "/admin/products", method: 'GET' do |f|
= f.label "has_orders"
= f.select :has_orders, [true, false], include_blank: true
-#
-# And the ransack part is right here...
-#
= f.fields_for #product_search.q, as: :q do |ransack|
= ransack.select :category_id_eq, Category.grouped_options
```
ok so now params[:product_search] holds the scopes and params[:product_search][:q] has the ransack goodness. We need to find a way, now, to distribute that data to the form object. So first let ProductSearch swallow it up in the controller:
The Controller
# products_controller.rb
def index
#product_search = ProductSearch.new(params[:product_search])
#products ||= #product_formobject.result.page(params[:page])
end
The Form Object
# product_search.rb
class ProductSearch
include Virtus.model
include ActiveModel::Model
# These are Product.scopes for the siphon part
attribute :has_orders, Boolean
attribute :sort_by, String
# The q attribute is holding the ransack object
attr_accessor :q
def initialize(params = {})
#params = params || {}
super
#q = Product.search( #params.fetch("q") { Hash.new } )
end
# siphon takes self since its the formobject
def siphoned
Siphon::Base.new(Product.scoped).scope( self )
end
# and here we merge everything
def result
Product.scoped.merge(q.result).merge(siphoned)
end
end