I'm kinda new to coding on rails. It would be great if you could help me out with what I think might be noob question.Here's my code:
def create
#project = Project.new(params[:project])
if #project.save
redirect_to new_project_path
end
student=#project.student_str.split(";")
#users = User.where(:code => student)
#users.each do |c|
puts c.email
end
#users.each do |c|
puts "I'm here"
c.projects = "#{c.projects};#{#project.id}"
end
end
So, in the create method, Each time a new project is created a string called student_str is stored where the ID number of each student is seperated by a ";". I split that string to an array using the split function to get an array of student ID's. I have the puts c.email and puts "I'm here" to make sure the loops are working fine. I get the proper outputs on terminal.
The problem here is the
c.projects = "#{c.projects};#{#project.id}"
That simply does not seem to be working.
My model is not updated when this line is executed. I get no errors though.
Can you tell me what I might have to do to fix this?
thanks!
You have to call c.save after you updated the projects attribute. Otherwise the object is updated but not the database so the next time you load it the changes are gone.
Related
I'm starting to know ROR and I was doing a kind of blog with articles, etc...
I did this code :
def show
id = params[:id]
list = Article.all
is_valid = false
list.all.each do |article|
if article.id == id
#is_valid = true
break
end
end
As you can see, this code just wants to check if the article ID exists or not. So I'm testing equality between id and article.id (which's a model linked to the appropriated table in the database) BUT when I try to use or display #is_valid boolean I saw that article.id == id is FALSE every time, even if article.id = 2 and id = 2. I tried to think about everything that can make this occuring, but I admit I still misunderstand this.
Then I ask you if you know why this is occuring. Of course, an equality like 2 == 2 will change #is_valid to true.
Thank you for your help !
Maybe its because params[:id] it's a string and article.id it's an Integer
(byebug) params
{"controller"=>"admin/my_controller", "action"=>"edit", "id"=>"1"}
And yes it is... "id" is a string "1", so you may try this:
def show
id = params[:id].to_i
list = Article.all
is_valid = false
list.all.each do |article|
if article.id == id
#is_valid = true
break
end
end
end
And maybe could work.
This is the answer to your question,
But if you want to learn a little more about Activerecord you can do this
Article.exists?(params[:id])
and that will do what you are trying to do just with a query against db.
and if you want to get just a simple article
record = Article.find_by(id: params[:id]) #return nil when not exist
if record # if nil will threat like false on ruby
#my code when exist
else
#my code when not exist
end
will work (you also can use find but find will throw an exception ActiveRecord::RecordNotFound when not exists so you have to catch that exception.
Activerecord has many ways to check this you dont need to do it by hand.
def show
#article = Article.find(params[:id])
end
This will create a database query which returns a single row. .find raises a ActiveRecord::NotFound exception if the record is not found. Rails catches this error and shows a 404 page. Article.find_by(id: params[:id]) is the "safe" alternative that does not raise.
Your code is problematic since list = Article.all will load all the records out of the database which is slow and will exhaust the memory on the server if you have enough articles. Its the least effective way possible to solve the task.
If you want to just test for existence use .exists? or .any?. This creates a COUNT query instead of selecting the rows.
Article.where(title: 'Hello World').exists?
I'm new to rails and I'm working on a project where I'm having an issue. I'm trying to display all the gyms that have the same zipcode. When I tried the code below, it only displays 1 and not the other ones. How can display all the gym that have the same zip code?
controller
def gym
#fitness = Fitness.find_by(zip_code: params[:zip_code])
end
gym.html.erb
<%= #fitness.name %>
You're doing this to yourself. By definition, #find_by only returns a single record, or nil. You probably want #where instead:
Fitness.where(zip_code: params[:zip_code])
If that still doesn't work, check both your table data and the content of your params hash to make sure you're creating a valid query.
def gyms
#fitness = Fitness.where("zip_code = ?", params[:zip_code])
end
I am working on a Rails app, and I am attempting to insert attributes from JSONs as database entries. I'm running into a problem, though, and would appreciate some guidance.
I've been able to jam a few things together and come up with something that sort of works...
def create
#report_group = Array.new
#report_group.push({location:"home", comments:"Hello, database!"}, {location:"away", comments:"Goodbye, database!"})
#report_group.each do |x|
#new_report = Report.new(x)
#new_report.user_id = current_user.id
#new_report.save
end
end
private
def report_params(params)
params.permit(:user_id,:location,:comments)
end
This is a good first step - this commits two entries to my database, one for each of the hashes pushed into #report_group, but it is suffering from a problem - the create action does not reference the report_params whitelist.
I have built several Rails apps where entries are submitted one at a time via the standard Rails form helpers, but I have never done it with multiple JSONs like this before. Trying out the syntax I'd use in a typical form helper situation
#new_report = Report.new(report_params(x))
throws the expectable error undefined method permit' for #<Hash:0x007f966b35e270> but I am not sure what else to do here.
EDIT TO SHOW SOLUTION
Big thanks to #oreoluwa for pointing me in the right direction. Here's the solution that I came up with.
def create
#report_group = Array.new
#report_group.push({location:"home", comments:"Hello, database!"}, {location:"away", comments:"Goodbye, database!"})
#report_group.each do |x|
hash = ActionController::Parameters.new(x)
#new_report = Report.new(report_params(hash))
#new_report.user_id = current_user.id
#new_report.save
end
end
private
def report_params(params)
params.permit(:user_id,:location,:comments)
end
You're getting the error because a Hash is not the same as an ActionController::Parameters. In order to use the permit method with your Hash you may need to first convert it to ActionController::Parameters, as such:
hash = {location:"home", comments:"Hello, database!"}
parameter = ActionController::Parameters.new(hash)
parameter.permit(:user_id,:location,:comments)
I don't know if that is what you're looking for, but I thought to point you in the right direction.
so I'm working on a code snippet that essentially takes out 35 random ids from the table List.
What I would like to do to find the ids that got randomly generated, store them into a database called Status.
The purpose is to avoid duplication the next time I get a new 35 random ids from the List. So I never get the same random id twice.
Here's what I've tried, but been unsuccessful to get working.
#schedule = current_user.schedules.new
if #schedule.save
#user = User.find(params[:id])
Resque.enqueue(ScheduleTweets, #user.token)
#schedule.update_attribute(:trial, true)
flash[:notice] = "success"
redirect_to :back
else
flash[:alert] = "Try again."
redirect_to :back
end
and the worker:
def self.perform(user_token)
list = List.first(6)
#status = list.statuses.create
list.each do |list|
Status.create(list_id: "#{list}")
if list.avatar.present?
client.create_update(body: {text: "#{list.text}", profile_ids: profile_ids, media: { 'thumbnail' => 'http://png-1.findicons.com/files/icons/85/kids/128/thumbnail.png', 'photo' => 'http://png-1.findicons.com/files/icons/85/kids/128/thumbnail.png' } })
end
end
end
however the Status.create(list_id: #list) doesn't work.
Does anybody have any idea what is going on, and how I can make the list_ids get saved successfully to Status?
It's also associated:
list has many statuses, and status belongs to list
The following line of code is wrong:
Status.create(list_id: "#{list}") # WRONG
In your case the list variable is a List instance. And you're passing its string version to list_id which expects an integer.
Do this:
Status.create(list_id: list.id)
Or this:
list.statuses.create
I think the following will also work:
Status.create(list: list)
n00b question. I'm trying to loop through every User record in my database. The pseudo code might look a little something like this:
def send_notifications
render :nothing => true
# Randomly select Message record from DB
#message = Message.offset(rand(Message.count)).first
random_message = #message.content
#user = User.all.entries.each do
#user = User.find(:id)
number_to_text = ""
#user.number = number_to_text #number is a User's phone number
puts #user.number
end
end
Can someone fill me in on the best approach for doing this? A little help with the syntax would be great too :)
Here is the correct syntax to iterate over all User :
User.all.each do |user|
#the code here is called once for each user
# user is accessible by 'user' variable
# WARNING: User.all performs poorly with large datasets
end
To improve performance and decrease load, use User.find_each (see doc) instead of User.all. Note that using find_each loses the ability to sort.
Also a possible one-liner for same purpose:
User.all.map { |u| u.number = ""; puts u.number }