Getting the value from an array in the model in rails - ruby-on-rails

I have a relatively simple problem. I have a model named Item which I've added a status field. The status field will only have two options (Lost or Found). So I created the following array in my Item model:
STATUS = [ [1, "Lost"], [2, "Found"]]
In my form view I added the following code which works great:
<%= collection_select :item, :status, Item::STATUS, :first, :last, {:include_blank => 'Select status'} %>
This stores the numeric id (1 or 2) of the status in the database. However, in my show view I can't figure out how to convert from the numeric id (again, 1 or 2) to the text equivalent of Lost or Found.
Any ideas on how to get this to work? Is there a better way to go about this?
Many thanks,
Tony

You can define a method in your Item model:
class Item < ActiveRecord::Base
#
def status_str
Item::STATUS.assoc(status).last
end
end
And use it:
item.status_str # => "Lost" (if status == 1)
Or you can check out enum_fu plugin:
class Item < ActiveRecord::Base
#
acts_as_enum :status, ["Lost", "Found"]
end
and then item.status gives you string value:
item.status # => "Lost"

Related

activeadmin and dynamic store accessors fails on new resource

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

In RoR, how do I initialize fields in my model based on a field in my model that has no underlying database column?

I’m using Rails 4.2.7. I have an attribute in my model that doesn’t have a database field underneath it
attr_accessor :division
This gets initialized when I create a new object.
my_object = MyObject.new(:name => name,
:age => get_age(data_hash),
:overall_rank => overall_rank,
:city => city,
:state => state,
:country => country,
:age_group_rank => age_group_rank,
:gender_rank => gender_rank,
:division => division)
What I would like is when this field gets set (if it is not nil), for two other fields that do have mappings in the database to get set. The other fields would be substrings of the “division” field. Where do I put that logic?
I'd probably drop the attr_accessor :division and do it by hand with:
def division=(d)
# Break up `d` as needed and assign the parts to the
# desired real attributes.
end
def division
# Combine the broken out attributes as needed and
# return the combined string.
end
With those two methods in place, the following will all call division=:
MyObject.new(:division => '...')
MyObject.create(:division => '...')
o = MyObject.find(...); o.update(:division => '...')
o = MyObject.find(...); o.division = '...'
so the division and the broken out attributes will always agree with each other.
If you try to use one of the lifecycle hooks (such as after_initialize) then things can get out of sync. Suppose division has the form 'a.b' and the broken out attributes are a and b and suppose that you're using one of the ActiveRecord hooks to break up division. Then saying:
o.division = 'x.y'
should give you o.a == 'x' but it won't because the hook won't have executed yet. Similarly, if you start with o.division == 'a.b' then
o.a = 'x'
won't give you o.division == 'x.b' so the attributes will have fallen out of sync again.
I see couple of options here
You can add it in your controller as follows
def create
if params[:example][:division]
# Set those params here
end
end
Or you can use before_save In your model
before_save :do_something
def do_something
if division
# Here!
end
end

Getting rails3-autocomplete-jquery gem to work nicely with Simple_Form with multiple inputs

So I am trying to implement multiple autocomplete using this gem and simple_form and am getting an error.
I tried this:
<%= f.input_field :neighborhood_id, collection: Neighborhood.order(:name), :url => autocomplete_neighborhood_name_searches_path, :as => :autocomplete, 'data-delimiter' => ',', :multiple => true, :class => "span8" %>
This is the error I get:
undefined method `to_i' for ["Alley Park, Madison"]:Array
In my params, it is sending this in neighborhood_id:
"search"=>{"neighborhood_id"=>["Alley Park, Madison"],
So it isn't even using the IDs for those values.
Does anyone have any ideas?
Edit 1:
In response to #jvnill's question, I am not explicitly doing anything with params[:search] in the controller. A search creates a new record, and is searching listings.
In my Searches Controller, create action, I am simply doing this:
#search = Search.create!(params[:search])
Then my search.rb (i.e. search model) has this:
def listings
#listings ||= find_listings
end
private
def find_listings
key = "%#{keywords}%"
listings = Listing.order(:headline)
listings = listings.includes(:neighborhood).where("listings.headline like ? or neighborhoods.name like ?", key, key) if keywords.present?
listings = listings.where(neighborhood_id: neighborhood_id) if neighborhood_id.present?
#truncated for brevity
listings
end
First of all, this would be easier if the form is returning the ids instead of the name of the neighborhood. I haven't used the gem yet so I'm not familiar how it works. Reading on the readme says that it will return ids but i don't know why you're only getting names. I'm sure once you figure out how to return the ids, you'll be able to change the code below to suit that.
You need to create a join table between a neighborhood and a search. Let's call that search_neighborhoods.
rails g model search_neighborhood neighborhood_id:integer search_id:integer
# dont forget to add indexes in the migration
After that, you'd want to setup your models.
# search.rb
has_many :search_neighborhoods
has_many :neighborhoods, through: :search_neighborhoods
# search_neighborhood.rb
belongs_to :search
belongs_to :neighborhood
# neighborhood.rb
has_many :search_neighborhoods
has_many :searches, through: :search_neighborhoods
Now that we've setup the associations, we need to setup the setters and the attributes
# search.rb
attr_accessible :neighborhood_names
# this will return a list of neighborhood names which is usefull with prepopulating
def neighborhood_names
neighborhoods.map(&:name).join(',')
end
# we will use this to find the ids of the neighborhoods given their names
# this will be called when you call create!
def neighborhood_names=(names)
names.split(',').each do |name|
next if name.blank?
if neighborhood = Neighborhood.find_by_name(name)
search_neighborhoods.build neighborhood_id: neighborhood.id
end
end
end
# view
# you need to change your autocomplete to use the getter method
<%= f.input :neighborhood_names, url: autocomplete_neighborhood_name_searches_path, as: :autocomplete, input_html: { data: { delimiter: ',', multiple: true, class: "span8" } %>
last but not the least is to update find_listings
def find_listings
key = "%#{keywords}%"
listings = Listing.order(:headline).includes(:neighborhood)
if keywords.present?
listings = listings.where("listings.headline LIKE :key OR neighborhoods.name LIKE :key", { key: "#{keywords}")
end
if neighborhoods.exists?
listings = listings.where(neighborhood_id: neighborhood_ids)
end
listings
end
And that's it :)
UPDATE: using f.input_field
# view
<%= f.input_field :neighborhood_names, url: autocomplete_neighborhood_name_searches_path, as: :autocomplete, data: { delimiter: ',' }, multiple: true, class: "span8" %>
# model
# we need to put [0] because it returns an array with a single element containing
# the string of comma separated neighborhoods
def neighborhood_names=(names)
names[0].split(',').each do |name|
next if name.blank?
if neighborhood = Neighborhood.find_by_name(name)
search_neighborhoods.build neighborhood_id: neighborhood.id
end
end
end
Your problem is how you're collecting values from the neighborhood Model
Neighborhood.order(:name)
will return an array of names, you need to also collect the id, but just display the names
use collect and pass a block, I beleive this might owrk for you
Neighborhood.collect {|n| [n.name, n.id]}
Declare a scope on the Neighborhood class to order it by name if you like to get theat functionality back, as that behavior also belongs in the model anyhow.
edit>
To add a scope/class method to neighborhood model, you'd typically do soemthing like this
scope :desc, where("name DESC")
Than you can write something like:
Neighborhood.desc.all
which will return an array, thus allowing the .collect but there are other way to get those name and id attributes recognized by the select option.

How to show a text field based on user's selection?

I have an array
ABC = ["A","B","C"]
<%= f.select :abc, model::ABC, :include_blank => true %>
If I select C, then I want to display an input field for "city" and "state". Otherwise, those fields should be hidden. Is there any simple way of doing this. I don't want to use jQuery or Ajax.
I don't know of a way to change what fields are being displayed without using javascript.
What you could do is always display the city and state fields, but only require them if the select menu is set to C. For example, define a validation rule that requires a field if the select menu is set to C. In your lib/ directory, make require_if_c_validator.rb
class RequireIfCValidator < ActiveModel::EachValidator
def validate_each object, attribute, value
if object.your_attribute_name == 'C' && value == nil
object.errors[attribute] < 'is required'
end
end
end
And then in your model, call it on city and state:
validate :city, :require_if_c => true
validate :state, :require_if_c => true

How to implenent mongodb 'includes?' finder condition

I am using Mongoid and have a project and a user model.
in the Project model, I have a field
class Project
include Mongoid::Document
field :name
field :user_ids, :type => Array
end
class User
include Mongoid::Document
field :email
end
I can find all the users belonging to one project, i.e., 'find this project's users'
#project = Project.first # => 'Housework'
User.criteria.id(#project.user_ids) # => ['Bart','Lisa','Maggie']
But I am having a bit trouble finding all the projects belonging to one user, i.e, 'find this user's projects'
#user = User.first # => 'Bart'
Project.where(:user_ids => #user.id) # doesn't work
Project.where(:user_ids.includes => #user.id) # not such method
Project.where(:user_ids => [#user.id]) # doesn't make sense to compare arrays, but tried anyway and doesn't work
I know that you can have another field in the User model to store project_ids, I would gladly do that, but I am just curious, is there a method to be used in finder conditions that works similarly to #includes? in ruby?
I found a solution to this. it is the all_in finder method
example:
Fruit.all[0].colors = ['red','green','blue'] #=> apple
Fruit.all[1].colors = ['yellow','green'] #=> banana
Fruit.all[2].colors = ['red', 'yellow'] #=> pineapple
To find all fruits that have the color red in their 'colors' array field, one can query:
Fruit.all_in(:colors => ['red'])
=>[apple, pineapple]

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