I am having trouble with datamapper not updating a model. I can create and save models without issue. I have enabled raise_on_save_failure and checked the return value of update but see no errors.
Here is the model:
class UserProfile
include DataMapper::Resource
attr_accessor :id, :wants_hints, :is_beta_user
property :id, Serial #auto-increment integer key
property :is_beta_user, Boolean
property :wants_hints, Boolean
has 1, :user, :through => Resource
end
And here is where it is updated in the controller:
if user = User.get(request.session[:user])
if request.params[:user_profile]
beta = request.params[:user_profile].has_key?('is_beta_user')
hints = request.params[:user_profile].has_key?('wants_hints')
user.user_profile.update({:is_beta_user => beta, :wants_hints => hints}) # returns true
Log.puts user.user_profile.errors.each {|e| Log.puts e.to_s} # returns empty list []
end
end
When the controller is called update always returns true, and there are never errors in the error list. The datamapper log, which is set to :debug, only shows the SELECT queries for retrieving the user and user_profile and that is all. Why would I be able to save a newly created model, but not be allowed to update that same model?
Removing attr_accessor fixed the problem. From my research attr_accessor is used for attributes not in the database.
DataMapper's save and update do not necessarily produce an UPDATE sentence. It will only do so if the data held by the model object has changed. So, for example, in the following code the update will return true but will not produce an UPDATE:
# This generates an INSERT
user = User.create(:login => 'kintaro', :email => 'kintaro#example.com')
# This does NOT generate an UPDATE
user.update(:login => 'kintaro')
If you do this, however, an UPDATE will be produced:
# This generates an UPDATE
user.update(:login => 'kintaro22')
Maybe this is what's happening?
Related
I'm creating a Sinatra App using Datamapper.
With the following route, I'm attempting to print the record for an id. So localhost:9292/api/1 should return results for id=1
inside
get '/api/:id' do
I tried a couple things with varied results:
thing = Thing.get(params[:id])
thing.to_json
end
outputs 'null', but:
id_param = params[:id]
id_param
end
prints 1 as expected, and:
hardcoded_thing = Thing.get(1)
hardcoded_thing.to_json
end
correctly prints the hardcoded db record with id=1. So I must be losing it..
Any ideas?
Thanks!
For reference, here's my model:
class Thing
include DataMapper::Resource
include BCrypt
property :id, Serial, :key => true
property :created_at, DateTime
property :updated_at, DateTime
property :name, String, :length => 50
property :cafe_topic, Text
end
Try this:
get '/api/:id' do |id|
thing = Thing.get(id)
thing.to_json
end
Here is my question.
I have 2 associated Datamapper models:
class Task
include DataMapper::Resource
property :id, Serial
property :date, Date
property :amount, Float
belongs_to :project, :required => true
end
class Project
include DataMapper::Resource
property :id, Serial
property :name, String, :required => true
property :desc, Text
belongs_to :company
has n, :tasks
end
My goal is to created JSON that will contain task date, amount and project name, that should be matched by project_id. At the moment JSON generation has following look:
Task.all.to_json(:only => [:date, :amount, :project_id])
I can access project_id from Task model, but have no idea how to add respective project name from Project model for every task. In SQL it looks like join:
select tasks.date, tasks.amount, projects.name from tasks
inner join projects
on tasks.project_id = projects.id;
Can you suggest correct way to create final JSON, using Datamapper way, but not SQL?
Thank you.
I have found solution for my problem. Here it is:
# create new structure to store merged result
Task_entry = Struct.new(:date, :amount, :pname)
# array to get results from database
all_task_items = Array.new
# run through result and fill the array with required data
Task.all.each do |task|
task_item = Task_entry.new(task.date, task.amount, task.project.name)
all_task_items << task_item
end
all_task_items.to_json # generate json
It works for me well. Hope it can be helpful.
I use datamapper for the database. I have a table.
class ZedTable
include DataMapper::Resource
property :id, Serial
property :label, String
property :now, Boolean, :default => false
before :save do
ZedTable.all.update(:now => false)
self.now = true
end
end
That is, I want only one value was true. But when I save the data I get an error.
Failure/Error: Unable to find matching line from backtrace
SystemStackError:
stack level too deep
Why? And how do I solve this problem?
Thanks.
You get are getting stack too deep because when you call update, it first calls before :save hook again. The method you need is update!, it bypasses the hooks.
I have a simple user model
class User < ActiveRecord::Base
has_one :user_profile
end
And a simple user_profile model
class UserProfile < ActiveRecord::Base
belongs_to :user
end
The issue is when I call the following build method, without calling the save method, I end up with a new record in the database (if it passes validation)
class UserProfilesController < ApplicationController
def create
#current_user = login_from_session
#user_profile = current_user.build_user_profile(params[:user_profile])
##user_profile.save (even with this line commented out, it still save a new db record)
redirect_to new_user_profile_path
end
Anyyyyyy one have anyyy idea what's going on.
The definition of this method says the following but it's still saving for me
build_association(attributes = {})
Returns a new object of the associated type that has been instantiated with attributes and linked to this object through a foreign key, but has not yet been saved.
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_one
Ok, I'm sure experienced vets already know this, but as a rookie I had to figure it out the long way...let me see if I can explain this without screwing it up
Although I was not directly saving the user_profile object, I noticed in my logs that something was updating the user model's last_activity_time (and the user_profile model) each time I submitted the form (the user model's last_activity date was also updated when the logged in user did various other things too - I later realized this was set in the Sorcery gem configuration).
Per http://api.rubyonrails.org/classes/ActiveRecord/AutosaveAssociation.html
AutosaveAssociation is a module that takes care of automatically saving associated records when their parent is saved. In my case, the user mode is the parent and the scenario they provide below mirrors my experience.
class Post
has_one :author, :autosave => true
end
post = Post.find(1)
post.title # => "The current global position of migrating ducks"
post.author.name # => "alloy"
post.title = "On the migration of ducks"
post.author.name = "Eloy Duran"
post.save
post.reload
post.title # => "On the migration of ducks"
post.author.name # => "Eloy Duran"
The following resolutions resolved my problem
1. Stopping Sorcery (config setting) from updating the users last_activity_time (for every action)
or
2. Passing an ':autosave => false' option when I set the association in the user model as follows
class User < ActiveRecord::Base
has_one :user_profile, :autosave => false
end
I have a relational DB defined as follows. How can I enter a new value, where B belongs to A. The code given below doesn't seem to work.
Thanks
class A
include DataMapper::Resource
property :id, Serial, :key => true
property :name, String
belongs_to :b
end
class B
include DataMapper::Resource
property :id, Serial, :key => true
property :name, String
has n, :as
end
Create new value
# Create new value
post '/create' do
a = A.new
b = B.new
b.attributes = params
b.belongs_to = a #problem is here
b.save
redirect("/info/#{a.id}")
end
#belongs_to is a model (class) method and you use it to declare ManyToOne relationship.
In your example you should use "<<" method like this:
b.as << a
That will add "a" instance to "as" collection and associate both resources.
[...] How can I enter a new value, where B belongs to A. The code given below doesn't seem to work.
Your code implies you're after A belonging to B, but your question is the reverse so I'll show how to do that, i.e., B belongs to A.
class A
include DataMapper::Resource
property :id, Serial, :key => true
property :name, String
has n, :bs # A has many B's
end
class B
include DataMapper::Resource
property :id, Serial, :key => true
property :name, String
belongs_to :a, :required => false # B has only 1 A
end
Note your has and belongs_to are reversed here. I also added required => false to the belongs_to side because DataMapper will silently refuse to save your model if ever don't have b.a before calling save—once you're comfortable with it you can remove the required false if you desire.
Here are two ways you can use that model:
# Create new value
post '/create' do
a = A.new
a.save
b = B.new
b.attributes = params
b.a = a
b.save
redirect("/info/#{a.id}")
end
This example is generally the same as yours, but I added a save call for A. Note this may not be necessary, I'm not in a good place to test this particular case; in the past I've found DataMapper will save some related objects automatically but not others so I've developed the habit of always saving explicitly to prevent confusion.
# Create new value
post '/create' do
a = A.create
b = a.bs.create(params)
redirect("/info/#{a.id}")
end
In the second example I call create on the many-side of the relationship, this makes a new B, associates it with "a", sets the params given, and saves it immediately. The result is the same as the previous example.
If you're just getting familiar with DataMapper, you may find it helpful to add the following to your app:
DataMapper::Model.raise_on_save_failure = true
This will cause DataMapper to give you errors and backtraces in cases like the above, more info here.