I have a model, Domain, which has a text field, names.
> rails g model Domain names:text
invoke active_record
create db/migrate/20111117233221_create_domains.rb
create app/models/domain.rb
> rake db:migrate
== CreateDomains: migrating ==================================================
-- create_table(:domains)
-> 0.0015s
== CreateDomains: migrated (0.0066s) =========================================
I set this field as serialized into an array in the model.
# app/models/domain.rb
class Domain < ActiveRecord::Base
serialize :names, Array
end
Create the ActiveAdmin resource for this model
> rails g active_admin:resource Domain
create app/admin/domains.rb
then, in the app/admin/domains.rb, I setup the various blocks to handle the serialized field as such
# app/admin/domains.rb
ActiveAdmin.register Domain do
index do
id_column
column :names do |domain|
"#{domain.names.join( ", " ) unless domain.names.nil?}"
end
default_actions
end
show do |domain|
attributes_table do
row :names do
"#{domain.names.join( ", " ) unless domain.names.nil?}"
end
end
end
form do |f|
f.inputs "Domain" do
f.input :names
end
f.buttons
end
# before we save, take the param[:domain][:name] parameter,
# split and save it to our array
before_save do |domain|
domain.names = params[:domain][:names].split(",") unless params[:domain].nil? or params[:domain][:names].nil?
end
end
Nearly everything works great -- my names are displayed as comma separated in the index and show views. When I update a record with my names field set to "a,b,c", the before_save works to turn that into an array that is then saved via the ActiveRecord serialize.
What I can not solve is how to make the edit form put in a comma-separated list into the text field. I tried using a partial and using formtastic syntax directly as well as trying to make it work via the active_admin DLS syntax. Does anyone know how to make this work?
Specifically, if I have the following array saved in my domain.names field:
# array of names saved in the domain active_record
domain.names = ["a", "b", "c"]
how to change:
form do |f|
f.inputs "Domain" do
f.input :names
end
f.buttons
end
so that when the edit form is loaded, in the text field instead of seeing abc, you see a,b,c.
Here is a summary of how I handled this situation. I added an accessor to the model which can turn the Array into a string joined by a linefeed and split it back to an Array.
# app/models/domain.rb
class Domain < ActiveRecord::Base
serialize :names, Array
attr_accessor :names_raw
def names_raw
self.names.join("\n") unless self.names.nil?
end
def names_raw=(values)
self.names = []
self.names=values.split("\n")
end
end
then, in my admin resource for domain, instead of using the :names field, I used the :names_raw field. setting this value would save the names Array with the new values.
# app/admin/domains.rb
form do |f|
f.inputs "Domain" do
f.input :names_raw, :as => :text
end
f.buttons
end
Stumbled on this question looking for something to have access to a serialized Hash's YAML. I used this solution on Rails 3.2:
def target_raw
#attributes['target'].serialized_value
end
def target_raw=(new_value)
#attributes['target'].state = :serialized
#attributes['target'].value = new_value
end
Related
In my rails model I have a JSON column which stores some meta information.
This is to be entered bu the user from a form.
Since the keys of the JSON column are not attributes of the model I cannot use them directly in form_for instead I need to define a virtual attribute.
Since this number of virtual attributes could grow to be arbitrarily lengthy I would like to use meta programming to define the attributes.
I did try the answer in this question however when I use the constant in my model I get an error saying that the constant is undefined. So I added the symbols for the keys in an array directly and iterate over them in the module. When I do this I get an error that says stack level too deep.
Please can someone help me out here?
If you are using PostgreSQL specific columns like hstore or json simply use store_accessor instead to generate the accessor methods. Be aware that these columns use a string keyed hash and do not allow access using a symbol.
class Model < ActiveRecord::Base
store_accessor :my_json_column, [ :key_1, :key_2, key_3 ]
end
What it doing under the hood? It has define write\read helper methods:
def store_accessor(store_attribute, *keys)
keys = keys.flatten
_store_accessors_module.module_eval do
keys.each do |key|
define_method("#{key}=") do |value|
write_store_attribute(store_attribute, key, value)
end
define_method(key) do
read_store_attribute(store_attribute, key)
end
end
end
# .....
store
I figured it out. I return the attribute as a key of the JSON column and it works fine now.
# lib/virtuals.rb
module Virtuals
%W(key_1 key_2 key_3).each do |attr|
define_method(attr) do
self.my_json_column[attr]
end
define_method("#{attr}=") do |val|
self.my_json_column[attr] = val
end
end
end
In my Model i just need to include that above module and it works fine in the form_for and updates correctly as well.
I am running Ruby 2.1 and Mongoid 5.0 (no Rails).
I want to track on a before_save callback whether or not an embedded field has changed.
I can use the document.attribute_changed? or document.changed methods to check normal fields, but somehow these don't work on relations (embed_one, has_one, etc).
Is there a way of detecting these changes before saving the document?
My model is something like this
class Company
include Mongoid::Document
include Mongoid::Attributes::Dynamic
field :name, type: String
#...
embeds_one :address, class_name: 'Address', inverse_of: :address
#...
before_save :activate_flags
def activate_flags
if self.changes.include? 'address'
#self.changes never includes "address"
end
if self.address_changed?
#This throws an exception
end
end
One example of how I save my document is:
#...
company.address = AddressUtilities.parse address
company.save
#After this, the callback is triggered, but self.changes is empty...
#...
I have read the documentation and Google the hell out of it, but I can't find a solution?
I have found this gem, but it's old and doesn't work with the newer versions of Mongoid. I want to check if there is another way of doing it before considering on trying to fix/pull request the gem...
Adding these two methods to your Model and calling get_embedded_document_changes should provide you an hash with the changes to all its embedded documents:
def get_embedded_document_changes
data = {}
relations.each do |name, relation|
next unless [:embeds_one, :embeds_many].include? relation.macro.to_sym
# only if changes are present
child = send(name.to_sym)
next unless child
next if child.previous_changes.empty?
child_data = get_previous_changes_for_model(child)
data[name] = child_data
end
data
end
def get_previous_changes_for_model(model)
data = {}
model.previous_changes.each do |key, change|
data[key] = {:from => change[0], :to => change[1]}
end
data
end
[ source: https://gist.github.com/derickbailey/1049304 ]
I want to access multiple columns using Rails 3.But it gave me the following error.
Error:
ArgumentError (wrong number of arguments (2 for 1)):
app/controllers/payments_controller.rb:13:in `check_type'
Check my below code.
payment_controller.rb:
class PaymentsController < ApplicationController
def payment
#payment=Vendor.new
respond_to do |format|
format.html
format.js
end
end
def check_type
if params[:commit]=="submit"
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).pluck(:type ,:Receipt_No)
#vendor_type.each do |vendor|
end
else
#v_name=Vendor.where(:s_catagory => params[:payment][:s_catagory] ).pluck(:v_name)
end
end
end
Actually i want to retrive data like below format.
#vendor_type=["Receipt_no":"type","Receipt_no":"type",.....]
Once these data will appear,I need how to access row values according to Receipt_No.Please help me to resolve this error.
Thanks to ActiveRecord >= 4 . pluck accepts multiple arguments so in
Rails 4: Your query will work
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).pluck(:type ,:Receipt_No)
Now as you are using Rails 3 which doesn't support multiple arguments to pluck then we can extend ActiveRecord::Relation itself like this:
put your file under config/initializers
# pluck_all.rb
module ActiveRecord
class Relation
def pluck_all(*args)
args.map! do |column_name|
if column_name.is_a?(Symbol) && column_names.include?(column_name.to_s)
"#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(column_name)}"
else
column_name.to_s
end
end
relation = clone
relation.select_values = args
klass.connection.select_all(relation.arel).map! do |attributes|
initialized_attributes = klass.initialize_attributes(attributes)
attributes.each do |key, attribute|
attributes[key] = klass.type_cast_attribute(key, initialized_attributes)
end
end
end
end
end
Now in your controller you can pass multiple arguments to pluck like this:
# payment_controller.rb:
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).pluck_all(:type ,:Receipt_No)
Now you can use pluck_all in whole app. Hope this helps ;)
EDIT:
Try below code if plcuk_all not worked:
#vendor_type = PaymentVendor.where(:v_name => params[:v_name]).map{|v|[v.type ,v.Receipt_No]}
Reference for more info: http://meltingice.net/2013/06/11/pluck-multiple-columns-rails/
Your pluck(:type ,:Receipt_No) looks wrong,
pluck have only one argument.
Also your type of data #vendor_type is wrong, Array don't have key, value pair.
Use map like this,
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).map { |i| [i.Receipt_No] }
In terms of making a rails 3 method that behaves the same as the Rails 4 pluck with multiple columns. This outputs a similar array (rather than a hashed key value collection). This should save a bit of pain if you ever come to upgrade and want to clean up the code.
See this tutorial which outlines a similar method that outputs a hash.
config/initializers/pluck_all.rb
module ActiveRecord
class Relation
def pluck_all(*args)
args.map! do |column_name|
if column_name.is_a?(Symbol) && column_names.include?(column_name.to_s)
"#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(column_name)}"
else
column_name.to_s
end
end
relation = clone
relation.select_values = args
klass.connection.select_all(relation.arel).map! do |attributes|
initialized_attributes = klass.initialize_attributes(attributes)
attributes.map do |key, attribute|
klass.type_cast_attribute(key, initialized_attributes)
end
end
end
end
end
Standing on the shoulders of giants and all
I have this model:
class CompanyCrawler < ActiveRecord::Base
....
serialize :entry_pages, Array
def entry_page_objects
entry_pages.map { |url| EntryPage.new(url) }
end
def entry_page_objects_attributes=(attributes)
# ...
end
....
end
This form to render the model:
.....
%p
%p
= crawler_form.label 'Entry pages'
= crawler_form.text_area :entry_pages_text, size: '80x6'
%ul.entry-pages
= crawler_form.fields_for :entry_page_objects do |entry_page_field|
%li=entry_page_field.text_field :url, size: 80
%a{href: '#', class: 'add-button'} Add Entry Page
The problem I have is that the form renders the entry_page_object input names incorrectly(e.g. company_crawler[entry_page_objects_attributes][0][url] instead of company_crawler[entry_page_objects][0][url]). I am really not sure what to do, I have read the documentation and the example says that just by defining attr_attributes=(attributes) and persisted? I will be able to use fields_for for collections just if they were associations defined with accept_nested_fields.
I have seen different solutions like just giving String 'entry_page_objects[]' to fields_for but I want to be consistent with rails naming convention and I know I can use form_tag instead of form_for but I want to make fields_for work as expected.
Here is some information for all that have not understood properly how nested_attributes works, like me.
What I have reported as issue is actually how it is supposed to work. When we have, let say, this model:
class Foo < ActiveRecord::Base # it has name attribute
has_many :larodis
accepts_nested_attributes_for :larodi
end
class Larodi < ActiveRecord::Base # it has name attribute
belongs_to :foo
end
This definition gives me the possibility to create Foo with many Larodi's just by giving a hash of parameters. For example:
x = Foo.create(name: 'Josh', larodi_attributes: [ {name: 'Wayne'} ]
x.larodis.map(&:name) # ['Wayne']
Now comes the part where #field_for understands if we have nested attribute to work with. We check this by looking for name_attributes= method. If it is defined #fields_for generates form of the type <input ... name=object[name][INDEX][method]>... where index is just an integer.
Keep in mind that when implementing custom name_attibutes(attributes) you must check attributes type - it can be Array like the example, it can be Hash of this type:
{ 1 => { ... } , 2 => { ... } }
Just like a hash representing array, where the key is index and value is the value for this index.
The answear looks like this:
_form.html.haml
....
= crawler_form.fields_for :entry_pages do |entry_page_field|
%li
=entry_page_field.text_field :url, size: 80
...
company_crawler.rb
class CompanyCrawler < ActiveRecord::Base
....
serialize :entry_pages, Array
def entry_pages_attributes=(attributes)
self.entry_pages = attributes_collection(attributes).map do |attribute|
EntryPage.new(attribute[:url])
end
end
def entry_pages=(entry_pages)
entry_pages = entry_pages.map do |entry_page|
cast_entry_page_to_entry_page_object(entry_page)
end
write_attribute(:entry_pages, entry_pages)
end
...
private
def attributes_collection(attributes)
case attributes
when Array
attributes
when Hash
attributes.values
end
end
def cast_entry_page_to_entry_page_object(entry_page)
case entry_page
when String
EntryPage.new(entry_page)
when EntryPage
entry_page
end
end
end
For clarity I have removed entry_page_objects and use only entry_pages.
In rails 4.0.2, I am trying to use a search plugin called dusen. Using this, I can search same model's values but I am not able to search other(associated) model values. How can I achieve this for single association(has_one / belongs_to) & multi association(has_many) model values?
Reference link:
https://github.com/makandra/dusen
Gem which I am using is dusen (0.4.10)
In controller,
#query = params[:query] || ""
Contact.search(#query)
In model,
belongs_to :city, :class_name=>"City"
search_syntax do
search_by :text do |scope, phrases|
columns = [:name, :contact_number, :email]
scope.where_like(columns => phrases)
end
end
Here, It will search only :name, :contact_number, :email fields, if i try to add below piece of code then it will show an error like undefined method 'search_text' for #<Dusen::Description:0xb438a248>
search_text do
[city.name]
end
Please suggest a solution for this issue.
Assuming your model name is 'User', you'd set it up as follows:
# User.rb
belongs_to :city, :class_name=>"City"
search_syntax do
search_by :text do |scope, phrases|
# namespaced fields to search by.
columns = ["users.name", "users.contact_number", "users.email", "cities.name"]
# specify association to City in scope.
scope.joins(:city).where_like(columns => phrases)
end
end
I hope this helps!