I'm trying to delete a single instance from a database query. "l.remove" represents what i want to do but i know its wrong. I have tried delete and destroy. destroy didn't work and delete actually removed the data from the database. I just want the data removed from the variable. Can anyone help me?
<%
#owner = User.find(params[:id])
#job_list = ShoppingList.where(:user_id=>#user.user_id)
#job_list.each do |l|
#temp = FlaggedCandidate.where(:flagged_user_id=>#owner.user_id, :list_id=>l.list_id)
if !#temp.nil?
l.remove
end
end
#candidate = FlaggedCandidate.new
%>
based on the code i assume that User has many ShoppingList.
You can do something like:
#job_list = #owner.shopping_lists.where( list_id: FlaggedCandidate.where( flagged_user_id: #owner.user_id ).pluck(:list_id) )
That could save the trouble of looping around.
You are trying to remove record from db. In order to just modify collection #job_list you need reject some unsatisfied elements. You can do it with select method (to select job_lists that flagged), or reject in opposite. This is how you code should looks like:
#owner = User.find(params[:id])
#job_list = ShoppingList.where(:user_id=>#user.user_id)
#job_list.select! do |job_list|
FlaggedCandidate.where(
:flagged_user_id => #owner.user_id,
:list_id => job_list.list_id
).any?
end
#candidate = FlaggedCandidate.new
select! simply change the original collection, instead of doing #job_list = #job_list.select { ... }
Related
I have a create method in Rails where I am trying to create multiple objects in a while loop. For some reason it doesn't seem to be hitting the while loop so no objects are being created. The code is below:
def create
#user = User.find(params[:participant][:user_id])
#activity = Activity.find(params[:activity_id])
weeks = #activity.weeks
i = 1
while i <= weeks do
puts "Test"
participant = Participant.new
participant.user_id = #user.id
participant.activity_id = #activity.id
participant.attended = false
participant.paid = false
participant.week = i
participant.save
i = i+1
end
redirect_to user_activities_path(#user, :id => #activity.id)
end
The form I am using to submit is working fine as I can see from the console, and the redirect_to method at the end is working, so it just seems to be missing the loop. If it helps, the value of weeks is 10. Any help would be greatly appreciated.
If multiple Test have been output, try participant.save!, i think the participant save might fail, like some column not valid, so no objects are being created.
Please check if activity record is get fetched. I think your 3rd statement should be as follow.
#activity = Activity.find(params[:participant][:activity_id])
Could someone take a look at my code and let me know if there is a better way to do this, or even correct where I'm going wrong please? I am trying to create a new row for each venue and variant.
Example:
venue_ids => ["1","2"], variant_ids=>["10"]
So, I would want to add in a row which has a venue_id of 1, with variant_id of 10. And a venue_id of 2, with variant_id of 10
I got this working, and it's now passing in my two arrays. I think I am almost there I'm not sure the .each is the right way to do it, but I think that I'm on the right track haha. I have it submitting, however, where would I put my #back_bar.save? because this might cause issues as it won't redirect
Thanks in advance.
def create
#back_bar = BackBar.new
#venues = params[:venue_ids]
#productid = params[:product_id]
#variants = params[:variant_ids]
# For each venue we have in the array, grab the ID.
#venues.each do |v|
#back_bar.venue_id = v
# Then for each variant we associate the variant ID with that venue.
#variants.each do |pv|
#back_bar.product_variant_id = pv
# Add in our product_id
#back_bar.product_id = #productid
# Save the venue and variant to the DB.
if #back_bar.save
flash[:success] = "#{#back_bar.product.name} has been added to #{#back_bar.venue.name}'s back bar."
# Redirect to the back bar page
redirect_to back_bars_path
else
flash[:alert] = "A selected variant for #{#back_bar.product.name} is already in #{#back_bar.venue.name}'s back bar."
# Redirect to the product page
redirect_to discoveries_product_path(#back_bar.product_id)
end
end # Variants end
end # Venues end
end
private
def back_bar_params
params.require(:back_bar).permit(:venue_id,
:product_id,
:product_variant_id)
end
as i said in comments
this is untested code and just showing you how it's possible to do with ease.
class BackBar
def self.add_set(vanue_ids, variant_ids)
values = vanue_ids.map{|ven|
variant_ids.map{|var|
"(#{ven},#{var})"
}
}.flatten.join(",")
ActiveRecord::Base.connection.execute("INSERT INTO back_bars VALUES #{values}")
end
end
def create
# use in controller
BackBar.add_set(params[:venue_ids], params[:variant_ids])
# ...
end
I have a problem for redirecting back after an action.
My condition is this:
Client, Volunteer, and staff has many next of kin. After creating a new next of kin, I want to redirect back to edit page of a particular client/volunteer/staff.
my current solution is this.
For the link to add
<%= link_to new_admin_people_next_of_kin_path(source: source,
source_id: source_id),
class: 'js-btn-add btn btn-success btn-sm' do %>
Add New Next of Kin
<% end %>
where
source = :client/:staff/:volunteer
source_id = id(primary key) or the staff/volunteer/client
my new method
def new
#person = Person.new
#person.source = params[:source]
#person.source_id = params[:source_id]
end
later I will pass source and source_id as hidden parameter.
my people_controller create method(because next of kin is a person)
def create
if params[:source] == 'client'
#client = Client.find(params[:source_id])
#pnok = #client.people_next_of_kin.build
elsif params[:source] == 'volunteer'
#volunteer = Volunteer.find(params[:source_id])
#pnok = #volunteer.people_next_of_kin.build
elsif params[:source] == 'staff'
#staff = Staff.find(params[:source_id])
#pnok = #staff.people_next_of_kin.build
else
#pnok = PeopleNextOfKin.new
end
#person = #pnok.build_next_of_kin
Person.transaction do
#person.update_attributes(create_params)
#person.save(validate: false)
end
end
as you can see, it's not really clean and hardcoded. I have read on polymorphic path, but I can't really find a way to use that for my solution as I need to build a new next of kin first and I cannot pass in an object in link_to or redirect_to, and then there's also a problem whereby the next of kin is not saved yet in database, so I cannot use person.find.
any solution?
It's a little tough to see what you are after from your example. I would guess that you want to redirect back to the staff / volunteer / client page and there would be a Parent / Child relationship with a NOK.
However, it's unclear what your models look like. For example, you might be using single table inheritance and polymorphism because these are all "People", or you might have the relationships in your models. I think the solution depends on which path you take.
For example, you might use something like this:
def Client
has_many :noks
end
If you had that, you could build the empty :nok record and then redirect back to the :client, and let the Rails / ActiveRecord internals manage the relationship. For example, the Client #show page may have places to list all Next of Kins that enumerates all of the kin.
Summary: I think you are trying to do too much in your controller without using models the way that RoR supports.
This should be a small question. I have a students table and a classifieds table in my schema. The model/table relationship is hook up in a way that when I do
#student = Student.first.classifieds.all
in the rails console I will get all the classifieds ad for this particular student
[#<Classified id: 3, ad_content: "在BC附近BU也可以、需要女生一起租房子、看了几处、俩人去租非常合算、限女生", ad_title: "BU和BC旁边的房子求室友一起租 ", student_id: 16, created_at: "2013-09-17 19:20:43", updated_at: "2013-09-17 19:49:31", location: "Allston">, #<Classified id: 1, ad_content: "Malden Towers 宽敞客厅出租，附带阳台，窗外是公寓的花园，客厅可用窗帘或木板隔开， 每月4...", ad_title: "Malden Towers 客厅出租 400/月", student_id: 16, created_at: nil, updated_at: "2013-09-17 19:47:55", location: "Malden">]
I am trying to filter through the records with specific conditions so only the records that satisfy this specific condition can be passed to the view therefore appear on that particular page.
I want to display the record only if the location is equal to malden.
in my students_controller.rb I have this
def malden_index
#student = Student.first
for classified in #student.classifieds.all
return classified if classified['location'] == 'Malden'
end
I have this in my view
<%= classified.ad_content %>
I am getting this error
undefined local variable or method `classified'
I have three questions
can I add the conditions in my view ? or does it have to be in my controller?
are my records returned to me in array data type?
What is the problem in my code? (I think its pretty straight forward)(the classified should be each record, then return the record only if the location key is equal to malden)
You shouldn't add this condition filtering in the view. It's much better when done in the controller.
The filtering can be done in multiple ways. It is usually best and fastest to let the database do the work:
#student.classifieds.where(:location => 'Malden').all
You can either forward variables by making them an instance variable #classifieds or pass it as local variable to your view with render 'malden_index', :locals => {:classifieds => #student.classifieds.all}
In general, the approach with return in your for-loop doesn't result in your desired filter. Either use my suggestion from #2 or build your array like this
#classifieds = []
for classified in #student.classifieds.all
#classifieds << classified if classified['location'] == 'Malden'
end
Or shorter and more 'ruby-way':
#classifieds = #student.classifieds.keep_if{|cf| cf['location'] == 'Malden'}
You could then access the #classifieds array in your view. Still, I very much suggest you rather use a database filter if possible.
First off: in the view you can only reach instance variables defined in the controller. So the for loop does not gather anything that is reachable in the view.
So you could fix that by doing
def malden_index
#student = Student.first
#classifieds = #student.classifieds.where('location="Malden"')
end
and in your view iterate over all the #classifieds.
Now notice: this is completely hardcoded.
I would solve this as follows: instead of using a separate index method, use the show action (of a student), check if a location is given, and if so, filter the classifieds accordingly.
That would look like this
def show
#student = Student.find(params[:id])
#classifieds = #student.classifieds
if params[:location]
#classifieds = #classifieds.where('location = ?', params[:location]
end
end
and then you would build the url as follows /students/1?location=malden.
If you then add the following route to config/routes.rb
get '/students/:id/:location', to: 'students#show'
you could improve that to /students/1/malden.
def malden_index
#student = Student.first
#classified = #student.classifieds.find_by_location("Malden")
end
In view:
<%= #classified.ad_content %>
Try this...
def malden_index
#student = Student.first
#classified = #student.classifieds.where(location: 'Malden').first
end
in view:
<%= #classified.ad_content %>
I have a create statement for some models, but it’s creating a record within a join table regardless of whether the record already exists.
Here is what my code looks like:
#user = User.find(current_user)
#event = Event.find(params[:id])
for interest in #event.interests
#user.choices.create(:interest => interest, :score => 4)
end
The problem is that it creates records no matter what. I would like it to create a record only if no record already exists; if a record does exist, I would like it to take the attribute of the found record and add or subtract 1.
I’ve been looking around have seen something called find_or_create_by. What does this do when it finds a record? I would like it to take the current :score attribute and add 1.
Is it possible to find or create by id? I’m not sure what attribute I would find by, since the model I’m looking at is a join model which only has id foreign keys and the score attribute.
I tried
#user.choices.find_or_create_by_user(:user => #user.id, :interest => interest, :score => 4)
but got
undefined method find_by_user
What should I do?
my_class = ClassName.find_or_initialize_by_name(name)
my_class.update_attributes({
:street_address => self.street_address,
:city_name => self.city_name,
:zip_code => self.zip_code
})
Assuming that the Choice model has a user_id (to associate with a user) and an interest_id (to associate with an interest), something like this should do the trick:
#user = User.find(current_user)
#event = Event.find(params[:id])
#event.interests.each do |interest|
choice = #user.choices.find_or_initialize_by_interest_id(interest.id) do |c|
c.score = 0 # Or whatever you want the initial value to be - 1
end
choice.score += 1
choice.save!
end
Some notes:
You don't need to include the user_id column in the find_or_*_by_*, as you've already instructed Rails to only fetch choices belonging to #user.
I'm using find_or_initialize_by_*, which is essentially the same as find_or_create_by_*, with the one key difference being that initialize doesn't actually create the record. This would be similar to Model.new as opposed to Model.create.
The block that sets c.score = 0 is only executed if the record does not exist.
choice.score += 1 will update the score value for the record, regardless if it exists or not. Hence, the default score c.score = 0 should be the initial value minus one.
Finally, choice.save! will either update the record (if it already existed) or create the initiated record (if it didn't).
find_or_create_by_user_id sounds better
Also, in Rails 3 you can do:
#user.choices.where(:user => #user.id, :interest => interest, :score => 4).first_or_create
If you're using rails 4 I don't think it creates the finder methods like it used to, so find_or_create_by_user isn't created for you. Instead you'd do it like this:
#user = User.find(current_user)
#event = Event.find(params[:id])
for interest in #event.interests
#user.choices.find_or_create_by(:interest => interest) do |c|
c.score ||= 0
c.score += 1
end
end
In Rails 4
You can use find_or_create_by to get an object(if not exist,it will create), then use update to save or update the record, the update method will persist record if it is not exist, otherwise update record.
For example
#edu = current_user.member_edu_basics.find_or_create_by(params.require(:member).permit(:school))
if #edu.update(params.require(:member).permit(:school, :majoy, :started, :ended))