Rails 4.2.1
Ruby 2.1.5
I have the following helper method:
def parse_potential_followers(params)
t_id = TestSet.where(:test_name => params[:test_set][:test_name]).pluck(:id)
screen_names = get_screen_names
screen_names.each do |s|
potential_follower = PotentialFollower.new(
:screen_name => s,
:test_sets_id => t_id,
:status => 'new',
:slug => generate_slug([t_id, s])
)
logger.info("Test Set ID: #{t_id}")
potential_follower.save
end
end
The problem is that when I call this method, the test_sets_id is skipped when data is inserted in the table. The three other attributes are saved fine.
I verified through logger.info that t_id is valid.
All the attributes are defined in the potential_followers table.
I also have all the attributes in the potential_follower_params method in the potential_followers_controller.rb:
def potential_follower_params
params.require(:potential_follower).permit(:screen_name, :test_sets_id, :connections, :status,
:slug, :created_at, :updated_at)
end
What am I forgetting?
Answer:
t_id is an array (result of ActiveRecord query). If t_id is changed to t_id[0] when used in the hash, it will work fine
You get t_id by
t_id = TestSet.where(:test_name => params[:test_set][:test_name]).pluck(:id)
which is an array. Probably you should try to get a variable with integer type instead of array. If your test_sets_id is an integer, the value in array won't be saved.
My guess is the data type is different. Maybe you are trying to save string as an integer?
Related
When I execute a Model.create method, if I specify a value for :id, it later gets nullified. Example:
Model.create (
:id => 50,
:name => Joe,
:enabled => yes
)
Instead what I have to do is use a .new and store it in a class variable, store my id value via the class variable, and then finally call a save:
m = Model.new (
:name => Joe,
:enabled => yes
)
m.id = 50
m.save
I am trying to execute this code in a seeds.rb, and this is NOT very DRY code. How can I do this better and achieve the same results?
id is just attr_protected. To prevent that, you can override the list of default protected attributes. Be careful doing this anywhere that attribute information can come from the outside. The id field is default protected for a reason.
class Model < ActiveRecord::Base
private
def attributes_protected_by_default
[]
end
end
or go with #Leo answer
This might be an answer for you. Model.create is basically a Model.new followed by a Model.save and since you are changing the id and saving again you might as well do
m = Model.new {
:name => Joe,
:enabled => yes
}
m.id = 50
m.save!
That will rid you of doing two saves.
I have a class Sample
Sample.class returns
(id :integer, name :String, date :date)
and A hash has all the given attributes as its keys.
Then how can I initialize a variable of Sample without assigning each attribute independently.
Something like
Sample x = Sample.new
x.(attr) = Hash[attr]
How can I iterate through the attributes, the problem is Hash contains keys which are not part of the class attributes too
class Sample
attr_accessor :id, :name, :date
end
h = {:id => 1, :name => 'foo', :date => 'today', :extra1 => '', :extra2 => ''}
init_hash = h.select{|k,v| Sample.method_defined? "#{k}=" }
# This will work
s = Sample.new
init_hash.each{|k,v| s.send("#{k}=", v)}
# This may work if constructor takes a hash of attributes
s = Sample.new(init_hash)
Take a look at this article on Object initialization. You want an initialize method.
EDIT You might also take a look at this SO post on setting instance variables, which I think is exactly what you're trying to do.
Try this:
class A
attr_accessor :x, :y, :z
end
a = A.new
my_hash = {:x => 1, :y => 2, :z => 3, :nono => 5}
If you do not have the list of attributes that can be assigned from the hash, you can do this:
my_attributes = (a.methods & my_hash.keys)
Use a.instance_variable_set(:#x = 1) syntax to assign values:
my_attributes.each do |attr|
a.instance_variable_set("##{attr.to_s}".to_sym, my_hash[attr])
end
Note(Thanks to Abe): This assumes that either all attributes to be updated have getters and setters, or that any attribute which has getter only, does not have a key in my_hash.
Good luck!
I've got a model, Entity.
class Entity
include Mongoid::Document
field :x
field :y
field :z, type => Hash, :default => {} # new field
end
I added a new field to it, a hash. When I try to use it, I get an error. My code is:
e = Entity.first
if e.z["a"] # if there is a key of this in it?
e.z["a"] = e.z["a"] + 1
else
e.z["a"] = 1
end
But, this error with an undefined method get for hash. If I try to create an initializer for it, to set the values in an existing document, it errors with the same error. What am I doing wrong?
Initializer looks like:
e = Entity.first
e.write_attribute(:z, {})
Thanks
Sorted it.
It seems the answer is to set in Mongoid 1.9.5 the hash to:
field :hash_field, :type => Hash, :default => Hash.new
and it can access and initialize it. Not quite understanding why, but happy to have the answer !
In Rails 2.3.6 I'm storing some serialized data in a database field.
My "feed_event.data" field in my database is stored as text and is (for example) equal to:
{:post=>{:pic=>"http://s3.amazonaws.com/criticalcity/datas/3524/big_thumb/send-a-letter.jpg", :name=>"Un’istruzione perfetta", :id=>1995, :authors=>"Delilah"}, :user=>{:pic=>"http://s3.amazonaws.com/criticalcity/avatars/537/thumb/DSCN2744.JPG", :name=>"Luci!", :id=>537}}
Now I need to output this field as a string (exactly as it is in the database), but when I ask:
puts feed_event.data
outputs:
postpichttp://s3.amazonaws.com/criticalcity/datas/3524/big_thumb/send-a-letter.jpgnameUn’istruzione perfettaid1995authorsDelilahuserpichttp://s3.amazonaws.com/criticalcity/avatars/537/thumb/DSCN2744.JPGnameLuci!
Why?
How can I output it as a yaml string?
UPDATE
In order to create it I have this in my FeedEvent model:
class FeedEvent < ActiveRecord::Base
has_many :user_feed_events, :dependent => :destroy
has_many :users, :through => :user_feed_events
serialize :data
end
And in order to create a new FeedEvent element I do:
feed = FeedEvent.create(:event_type => "comment #{commentable_type}", :type_id => id, :data => {:user => {:id => user.id, :name => user.name, :pic => user.avatar.url(:thumb)}, :comment => {:id => id, :body => body, :commentable_id => commentable_id, :commentable_type => :commentable_type, :commentable_name => commentable.name}})
UPDATE #2
following nzifnab's hint I used the .to_yaml method, but what Rails outputs in this case is:
data: "--- \n:post: \n :pic: http://s3.amazonaws.com/criticalcity/datas/3524/big_thumb/send-a-letter.jpg\n :authors: Delilah\n :name: \"Un\\xE2\\x80\\x99istruzione perfetta\"\n :id: 1995\n:user: \n :pic: http://s3.amazonaws.com/criticalcity/avatars/537/thumb/DSCN2744.JPG\n :name: Luci!\n :id: 537\n"
Also commenting "serialize :data" in the model outputs the same.
Thanks,
Augusto
When you call feed_data.data rails has automatically de-serialized your string. You could print it out like this:
feed_data.data.inspect to get the ruby hash representation as a string, but since it's already de-serialized it for you do you need to do anything else?
you can call everything on it like feed_data.data[:post][:pic]
I'm not sure what method you can use to grab the raw serialized string from the record, but usually you don't need to.
By default, serialization is made in a Hash.
Simply loop it to display it's content:
<% feed_event.data.each do |key, value| %>
<%= "#{key}: #{value}" %>
<% end %>
I'm just unsure about nesting level here but you've got the idea.
as you mentioned in your Update, the right way to do this is to put "serialize :data" in your model.
Then, you can access the data attribute as a Hash, that's the default, and it gets automatically persisted when you save your object.
Important Note:
One important thing for this to work is that you define the database field as text or string -- not as a binary field -- otherwise this will not work correctly!
G'day guys, I'm currently using fastercsv to construct ActiveRecord elements and I can't for the life of me see this bug (tired), but for some reason when it creates, if in the rake file i output the column I want to save as the element value, it puts out correctly, as either a Trade or a Quote
but when I try to save it into the activerecord, it won't work.
FasterCSV.foreach("input.csv", :headers => true) do |row|
d = DateTime.parse(row[1]+" "+row[2])
offset = Rational(row[3].to_i,24)
o = d.new_offset(offset)
t = Trade.create(
:name => row[0],
:type => row[4],
:time => o,
:price => row[6].to_f,
:volume => row[7].to_i,
:bidprice => row[10].to_f,
:bidsize => row[11].to_i,
:askprice => row[14].to_f,
:asksize => row[15].to_i
)
end
Ideas?
Name and Type are both strings, every other value works except for type. Have I missed something really simple?
Ruby's Object class has a type method. You need to t[:type] = row[4] to avoid that method.
-Tim