I'm trying to build an application on RoR that uses MongoDB via Mongoid for the main objects but has a like and dislike process using Redis via Opinions https://github.com/leehambley/opinions/.
It sort of works but when I run the methods on my objects I just get an error "undefined method `like_by'" where I think the methods are supposed to be autogenerated.
My model looks like:
class Punchline
include Mongoid::Document
include Opinions::Pollable
opinions :like, :dislike
field :key, type: String
field :text, type: String
field :won, type: Boolean
field :created, type: Time, default: ->{ Time.now }
field :score, type: Integer
index({ key: 1 }, { unique: true, name: "key_index" })
belongs_to :user
embedded_in :joke
end
and I run:
user = User.find(session[:userid])
#joke.punchlines.sample.like_by(user);
But it fails with the undefined method error :(
Do I need to initialize Opinions somewhere beyond
/config/initializers/opinions.rb
Opinions.backend = Opinions::RedisBackend.new
Redis.new(:host => 'localhost', :port => 6379)
So, it turns out that Opinions doesn't really work. Why is a bit beyond my two weeks with Rails :)
Anyway, it turns out that this is really easy to do by hand anyway especially as I only had a like and dislike to handle.
I used a Redis sorted set which allows a unique key - value pair with a score. I used a score of +1 or -1 to denote like or dislike and then encoded the key to represent the liked object and the value to be the user id.
This looked like:
def like(user)
$redis.zadd('joke:'+self.key+':likes', 1, user._id)
end
def dislike(user)
$redis.zadd('joke:'+self.key+':likes', -1, user._id)
end
def numLikes
res = $redis.zrangebyscore('joke:'+self.key+':likes',1,1);
return res.count
end
def numDislikes
res = $redis.zrangebyscore('joke:'+self.key+':likes',-1,-1);
return res.count
end
def likedBy(user)
res = $redis.zscore('joke:'+self.key+':likes',user._id)
return (res == 1)
end
def dislikedBy(user)
res = $redis.zscore('joke:'+self.key+':likes',user._id)
return (res == -1)
end
Related
I have been struggling with a Client request to filter out A model(Candidate) on the basis of Column Format
The issue I am facing is that column inputs either SSN or EIN.
The format for SSN is (xxx-xx-xxxx)
The format for EIN is (xx-xxxxxxx)
My candidates Table contains the field ssn_or_ein , which takes either one of these 2.
For ex:
candidate111.ssn_or_ein => 111-11-1111
candidate222.ssn_or_ein => 22-2222222
I have tried fetching all the 4000 accounts, but i suppose that's not how a developer's approach should be.
I am still learning Rails and any tip would be really helpful.
You can do this with a like query. Put it in a scope so it's easily available.
class Candidate < ApplicationRecord
scope with_ein -> { where( "ssn_or_ein like ?", "__-_______" }
scope with_ssn -> { where( "ssn_or_ein like ?", "___-__-____" }
end
However, this can get slow if ssn_or_ein is not properly indexed.
Consider storing them in two different columns. This makes validation and querying simpler. Bring them together only when you just need a TIN - Taxpayer Information Number.
class Candidate < ApplicationRecord
scope with_ein -> { where.not( ein: nil ) }
scope with_ssn -> { where.not( ssn: nil ) }
EIN_RE = %r{^\d{2}-\d{7}$}
SSN_RE = %r{^\d{3}-\d{2}-\d{4}$}
validates :ein, format: { with: EIN_RE }, allow_nil: true
validates :ssn, format: { with: SSN_RE }, allow_nil: true
def tin
ssn || ein
end
class << self
def find_by_tin(tin)
where( ssn: tin ).or( where(ein: tin) )
end
end
end
I would also suggest that you store the data "normalized", without the dashes, just the numbers. This is simpler to work with, and the accepted format can be changed without having to change all the data. Format them in a decorator.
I want to generate forms for a resource that has a postgres jsonb column :data, and I want the schema for these forms to be stored in a table in the database. After a lot of research I am 90% there but my method fails in ActiveAdmin forms upon create (not update). Can anyone explain this?
Sorry for the long code snippets. This is a fairly elaborate setup but I think it would be of some interest since if this works one could build arbitrary new schemas dynamically without hard-coding.
I am following along this previous discussion with Rails 6 and ActiveAdmin 2.6.1 and ruby 2.6.5.
I want to store Json Schemas in a table SampleActionSchema that belong_to SampleAction (using the json-schema gem for validation)
class SampleActionSchema < ApplicationRecord
validates :category, uniqueness: { case_sensitive: false }, allow_nil: false, allow_blank: true
validate :schema_is_json_schema
private
def schema_is_json_schema
metaschema = JSON::Validator.validator_for_name("draft4").metaschema
unless JSON::Validator.validate(metaschema, schema)
errors.add :schema, 'not a compliant json schema'
end
end
end
class SampleAction < ActiveRecord::Base
belongs_to :sample
validate :is_sample_action
validates :name, uniqueness: { case_sensitive: false }
after_initialize :add_field_accessors
before_create :add_field_accessors
before_update :add_field_accessors
def add_store_accessor field_name
singleton_class.class_eval {store_accessor :data, field_name.to_sym}
end
def add_field_accessors
num_fields = schema_properties.try(:keys).try(:count) || 0
schema_properties.keys.each {|field_name| add_store_accessor field_name} if num_fields > 0
end
def schema_properties
schema_arr=SampleActionSchema.where(category: category)
if schema_arr.size>0
sc=schema_arr[0]
if !sc.schema.empty?
props=sc.schema["properties"]
else
props=[]
end
else
[]
end
end
private
def is_sample_action
sa=SampleActionSchema.where(category: category)
errors.add :category, 'not a known sample action' unless (sa.size>0)
errors.add :base, 'incorrect json format' unless (sa.size>0) && JSON::Validator.validate(sa[0].schema, data)
end
end
This all works correctly; For example, for a simple schema called category: "cleave", where :data looks like data: {quality: "good"}, I can create a resource as follows in the rails console:
sa=SampleAction.new(sample_id: 6, name: "test0", data: {}, category: "cleave" )
=> #<SampleAction id: nil, name: "test0", category: "cleave", data: {}, created_at: nil, updated_at: nil, sample_id: 6>
sa.quality = "good" => true
sa.save => true
To make this system work in AA forms, I call the normal path (new or edit)_admix_sample_action_form with params: {category: "cleave"} and then I generate permit_params dynamically:
ActiveAdmin.register SampleAction, namespace: :admix do
permit_params do
prms=[:name, :category, :data, :sample_id, :created_at, :updated_at]
#the first case is creating a new record (gets parameter from admix/sample_actions/new?category="xxx"
#the second case is updating an existing record
#falls back to blank (no extra parameters)
categ = #_params[:category] || (#_params[:sample_action][:category] if #_params[:sample_action]) || nil
cat=SampleActionSchema.where(category: categ)
if cat.size>0 && !cat[0].schema.empty?
cat[0].schema["properties"].each do |key, value|
prms+=[key.to_sym]
end
end
prms
end
form do |f|
f.semantic_errors
new=f.object.new_record?
cat=params[:category] || f.object.category
f.object.category=cat if cat && new
f.object.add_field_accessors if new
sas=SampleActionSchema.where(category: cat)
is_schema=(sas.size>0) && !sas[0].schema.empty?
if session[:active_sample]
f.object.sample_id=session[:active_sample]
end
f.inputs "Sample Action" do
f.input :sample_id
f.input :name
f.input :category
if !is_schema
f.input :data, as: :jsonb
else
f.object.schema_properties.each do |key, value|
f.input key.to_sym, as: :string
end
end
end
f.actions
end
Everything works fine if I am editing an existing resource (as created in the console above). The form is displayed and all the dynamic fields are updated upon submit. But when creating a new resource where e.g. :data is of the form data: {quality: "good"} I get
ActiveModel::UnknownAttributeError in Admix::SampleActionsController#create
unknown attribute 'quality' for SampleAction.
I have tried to both add_accessors in the form and to override the new command to add the accessors after initialize (these should not be needed because the ActiveRecord callback appears to do the job at the right time).
def new
build_resource
resource.add_field_accessors
new!
end
Somehow when the resource is created in the AA controller, it seems impossible to get the accessors stored even though it works fine in the console. Does anyone have a strategy to initialize the resource correctly?
SOLUTION:
I traced what AA was doing to figure out the minimum number of commands needed. It was necessary to add code to build_new_resource to ensure that any new resource AA built had the correct :category field, and once doing so, make the call to dynamically add the store_accessor keys to the newly built instance.
Now users can create their own original schemas and records that use them, without any further programming! I hope others find this useful, I certainly will.
There are a couple ugly solutions here, one is that adding the parameters to the active admin new route call is not expected by AA, but it still works. I guess this parameter could be passed in some other way, but quick and dirty does the job. The other is that I had to have the form generate a session variable to store what kind of schema was used, in order for the post-form-submission build to know, since pressing the "Create Move" button clears the params from the url.
The operations are as follows: for a model called Move with field :data that should be dynamically serialized into fields according to the json schema tables, both
admin/moves/new?category="cleave" and admin/moves/#/edit find the "cleave" schema from the schema table, and correctly create and populate a form with the serialized parameters. And, direct writes to the db
m=Move.new(category: "cleave") ==> true
m.update(name: "t2", quality: "fine") ==> true
work as expected. The schema table is defined as:
require "json-schema"
class SampleActionSchema < ApplicationRecord
validates :category, uniqueness: { case_sensitive: false }, allow_nil: false, allow_blank: true
validate :schema_is_json_schema
def self.schema_keys(categ)
sas=SampleActionSchema.find_by(category: categ)
schema_keys= sas.nil? ? [] : sas[:schema]["properties"].keys.map{|k| k.to_sym}
end
private
def schema_is_json_schema
metaschema = JSON::Validator.validator_for_name("draft4").metaschema
unless JSON::Validator.validate(metaschema, schema)
errors.add :schema, 'not a compliant json schema'
end
end
end
The Move table that employs this schema is:
class Move < ApplicationRecord
after_initialize :add_field_accessors
def add_field_accessors
if category!=""
keys=SampleActionSchema.schema_keys(category)
keys.each {|k| singleton_class.class_eval{store_accessor :data, k}}
end
end
end
Finally, the working controller:
ActiveAdmin.register Move do
permit_params do
#choice 1 is for new records, choice 2 is for editing existing
categ = #_params[:category] || (#_params[:move][:category] if #_params[:move]) || ""
keys=SampleActionSchema.schema_keys(categ)
prms = [:name, :data] + keys
end
form do |f|
new=f.object.new_record?
f.object.category=params[:category] if new
if new
session[:current_category]=params[:category]
f.object.add_field_accessors
else
session[:current_category] = ""
end
keys=SampleActionSchema.schema_keys(f.object.category)
f.inputs do
f.input :name
f.input :category
keys.each {|k| f.input k}
end
f.actions
end
controller do
def build_new_resource
r=super
r.assign_attributes(category: session[:current_category])
r.add_field_accessors
r
end
end
end
Each user has one address.
class User
include Mongoid::Document
has_one :address
end
class Address
include Mongoid::Document
belongs_to :user
field :street_name, type:String
end
u = User.find(...)
u.address.update(street_name: 'Main St')
If we have a User without an Address, this will fail.
So, is there a good (built-in) way to do u.address.update_or_initialize_with?
Mongoid 5
I am not familiar with ruby. But I think I understand the problem. Your schema might looks like this.
user = {
_id : user1234,
address: address789
}
address = {
_id: address789,
street_name: ""
user: user1234
}
//in mongodb(javascript), you can get/update address of user this way
u = User.find({_id: user1234})
u.address //address789
db.address.update({user: u.address}, {street_name: "new_street name"})
//but since the address has not been created, the variable u does not even have property address.
u.address = undefined
Perhaps you can try to just create and attached it manually like this:
#create an address document, to get _id of this address
address = address.insert({street_name: "something"});
#link or attached it to u.address
u.update({address: address._id})
I had this problem recently. There is a built in way but it differs from active records' #find_or_initialize_by or #find_or_create_by method.
In my case, I needed to bulk insert records and update or create if not found, but I believe the same technique can be used even if you are not bulk inserting.
# returns an array of query hashes:
def update_command(users)
updates = []
users.each do |user|
updates << { 'q' => {'user_id' => user._id},
'u' => {'address' => 'address'},
'multi' => false,
'upsert' => true }
end
{ update: Address.collection_name.to_s, updates: updates, ordered: false }
end
def bulk_update(users)
client = Mongoid.default_client
command = bulk_command(users)
client.command command
client.close
end
since your not bulk updating, assuming you have a foreign key field called user_id in your Address collection. You might be able to:
Address.collection.update({ 'q' => {'user_id' => user._id},
'u' => {'address' => 'address'},
'multi' => false,
'upsert' => true }
which will match against the user_id, update the given fields when found (address in this case) or create a new one when not found.
For this to work, there is 1 last crucial step though.
You must add an index to your Address collection with a special flag.
The field you are querying on (user_id in this case)
must be indexed with a flag of either { unique: true }
or { sparse: true }. the unique flag will raise an error
if you have 2 or more nil user_id fields. The sparse option wont.
Use that if you think you may have nil values.
access your mongo db through the terminal
show dbs
use your_db_name
check if the addresses collection already has the index you are looking for
db.addresses.getIndexes()
if it already has an index on user_id, you may want to remove it
db.addresses.dropIndex( { user_id: 1} )
and create it again with the following flag:
db.addresses.createIndex( { user_id: 1}, { sparse: true } )
https://docs.mongodb.com/manual/reference/method/db.collection.update/
EDIT #1
There seems to have changes in Mongoid 5.. instead of User.collection.update you can use User.collection.update_one
https://docs.mongodb.com/manual/reference/method/db.collection.updateOne/
The docs show you need a filter rather than a query as first argument but they seem to be the same..
Address.collection.update_one( { user_id: user_id },
'$set' => { "address": 'the_address', upsert: true} )
PS:
If you only write { "address": 'the_address' } as your update clause without including an update operator such as $set, the whole document will get overwritten rather than updating just the address field.
EDIT#2
About why you may want to index with unique or sparse
If you look at the upsert section in the link bellow, you will see:
To avoid multiple upserts, ensure that the filter fields are uniquely
indexed.
https://docs.mongodb.com/manual/reference/method/db.collection.updateOne/
This is a really simple question, but I'm having trouble with the syntax.
Rails 4, Ruby 2.
Have the following code working to serialize some records and dump them into geo json:
module Serializers
class GeoUser < ActiveModel::Serializer
attributes :type, :geometry, :properties
def type
'Feature'
end
def geometry
{
type: 'Point',
coordinates: [object.longitude, object.latitude]
}
end
def properties
{
name: object.full_name,
address: object.full_address,
:'marker-color' => object.marker_color,
:'marker-symbol' => object.marker_symbol,
:'marker-size' => object.marker_size
}
end
end
end
My problem is sometimes object.longitude, object.latitude are null/nil and I would like to set them to 0. Simple conditional statement, something like || 0, but I can't seem to get the syntax correct.
Suggestions, please :)
Thank you!
object.longitude || 0 will work, as will object.longitude.to_f (nil.to_f returns 0.0).
I have a model
class Transaction < ActiveRecord::Base
end
I have a transaction_type column which is an integer.
How can I create an enumeration that I could map values to names like:
one_time = 1
monthly = 2
annually = 3
So in the db column, the values would be 1, 2 or 3.
Also, whenever I create a new instance, or save a model and the field wasn't set like:
#transaction = Transaction.new(params)
It should default to 1 (on_time).
I'm not sure how I can do this?
basically the same answer as Amit, slight variation
class TransactionType
TYPES = {
:one_time => 1,
:monthly => 2,
:annually => 3
}
# use to bind to select helpers in UI as needed
def self.options
TYPES.map { |item| [item[0], item[1].to_s.titleize] }
end
def self.default
TYPES[:one_time]
end
end
one way to control the default value
class Transaction < ActiveRecord::Base
before_create :set_default_for_type
def set_default_for_type
type = TransactionType.default unless type.present?
end
end
but - best way is to just apply the defaults on your database column and let ActiveRecord get it from there automatically
NOTE: it might also make sense to just have a TransactionType ActiveRecord object instead of above, depends on your situation, i.e.
# on Transaction with type_id:integer
belongs_to :type, class_name: "TransactionType"
You can map the values by creating a constant either in the same Transaction model or by creating a new module and place it inside that as explained by #KepaniHaole
In Transaction model, you can do it like :
class Transaction < ActiveRecord::Base
TRANSACTION_TYPES = { 'one_time' => 1, 'monthly' => 2, 'monthly' => 3 }
end
You can access these values by accessing the constant as
Transaction::TRANSACTION_TYPES['one_time'] # => 1
Transaction::TRANSACTION_TYPES['monthly'] # => 2
Transaction::TRANSACTION_TYPES['monthly'] # => 3
To add a default value to transaction_type column just create a new migration with :
def up
change_column :transactions, :transaction_type, :default => Transaction::TRANSACTION_TYPES['one_time']
end
With this, every time you create a Transaction object without passing transaction_type, the default value 1 with be stored in it.
Maybe you could try something like this? Ruby doesn't really support c-style enums..
module TransactionType
ONCE = 1
MONTHLY = 2
ANUALLY = 3
end
then you could access their values like so:
#transaction = Transaction.new(TransactionType::ONCE)