I dont know is it possible but i have a form and when i submit the form, i want the records to be saved multiple times in database. As of now, i am not worried about efficiency , but to get this thing going.
#message = Message.new
<%= simple_form_for #message do |f| %>
<%= f.input :description, as: :text, input_html: {rows: 7}, label: false, placeholder: "Type your message ..." %>
<%= f.submit "Submit", class: "btn btn-info" %>
<%end%>
I want the above form to be saved multiple times, like (i know its dumb)
for i in 1..4
#message.save
end
Intention:
My intention here is to send a single message to all group members at once. So i have the group_id and description now and when users submits the form, i want to iterate over all the users who are following the group_id and save the records with respective user_id's who all are following group.
I dont think i need validation for this.
You don't have group_id in the form so I'm not sure if it's somewhere else but you claim to have it so I'll just assume you do.
#group = Group.find(group_id)
#group.users.each do |user|
message_params = params[:message].merge(user_id: user.id)
Message.create(message_params)
end
UPDATE
So I did some digging, and found out that this is not as trivial as I originally thought.
When you call #message.save, rails will go behind the scenes to check if that record is a new record (i.e. call #message.new_record?) If it is not a new record, it will update the existing one instead of creating a new one. If you can override that, you could save the record multiple times.
The issue I found when trying to set the new_record attribute directly was it is only called on initialization ( when #message.new is called) and if the record does not get initialized then new_record defaults to false.
As others have pointed out in comments, there really shouldn't need to be a reason to save an identical record (which is why rails doesn't easily allow it). If you want to assign the same message to multiple users, set up associations to relate the two models. If you need to use the same message every time you do something, create it once then simply fetch it from the database whenever you need to use it.
Related
I have a edit form that prepopulates with the current values. Its a custom edit screen (not the default one that rails uses) and what Im using it for is for users to submit changes that will get voted on and might eventually get applied to the record. However, in the time it takes to be voted on something else might have changed and I dont want to overwrite the changes if they didnt submit a change.
EDIT: Changing to my more specific case so hopefully answers will work for it...
I have the following tables: Recipes, RecipeIngredients, RecipeSteps, RecipeChanges. On the show view of my recipes it displays all the ingredients/steps and there is a tab that then changes just the ingredients/steps to forms as to allow the user to submit changes. I dont want these changes applied though. Instead Im trying to create a voting system where people can vote on them. So what I have decided on is to convert the parameters from the form into a json string and save it in the RecipeChanges table under a single column (instead of using two table for ingredient changes and step changes). Heres the code for the form (html removed to make it easier to see the rails stuff):
<%= form_for #recipe, url: recipe_recipe_changes_path(#recipe), html: {method: "post"}, remote: true do |f| %>
<%= f.fields_for :recipe_ingredients, f.object.recipe_ingredients.order(:order) do |ff| %>
<%= ff.hidden_field :order, class: "position" %>
<%= ff.text_field :ingredient, placeholder: "Add Ingredient (e.g. 3 cups cooked rice)" %>
<label><%= ff.check_box :_destroy %>Remove</label>
<% end %>
<%= f.fields_for :recipe_steps do |ff| %>
<%= ff.hidden_field :order, class: "position"%>
<%= ff.text_area :step %>
<label><%= ff.check_box :_destroy %>Remove</label>
<% end %>
<%= submit_tag "Submit", class: "button" %>
<% end %>
So this sends a recipe object to my RecipeChange controller and there I handle the params to save them as the json string like so:
def create
#change = RecipeChange.new
#change.recipe_id = params[:recipe_id]
#change.new_recipe = recipe_change_params.to_json
#if #change.save
#add alert for successfully adding
#else
# add code for error handling
#end
end
This works like I want except for it saves all the ingredients/steps and I would like to only save what they have changed. I had two thoughts on how to do this but not sure how to accomplish it.
Check if the fields have changed when they click the submit button and only send the ones that have been edited (not sure if possible)
In the controller grab the original recipe (I have the id so that would be easy) and loop through the ingredients/steps and compare them and remove any that are identical....this is the method I think would be better but not sure how to loop through the hashes to accomplish this
Have a look at ActiveModel::Dirty. http://api.rubyonrails.org/classes/ActiveModel/Dirty.html#method-i-changed
You can do something like:
changes = bag.changed_attributes and get a hash of that attributes that changed, and then save those with bag.update_attributes(changes), for example.
This is a bit old now but I've come across the same or similar scenario and wanted to share for others.
In my case I populate some nested form fields based on an existing object in my #new action. However, in my #create action I did not want to save these nested form params unless they were actually modified compared to the original existing object.
In this case, ActiveModel::Dirty would always be true as it would compare [nil, "value"].
I first tried to modify the params in my #create action and compare them to the original existing object similar to this discussion but this got messy and felt wrong.
I ended up saving all records then doing a cleanup with an instance method in my model that I call after save in my controller's #create action. Still feels a bit dirty but it's working.
Example:
# controllers/changes_controller.rb
# ChangeController#create
def create
# ... shortened for example ...
if #instance.save
#instance.remove_clean_changes
format.html
end
end
# models/change.rb
# Change#remove_clean_changes
# Loop over all original objects and compare the necessary attributes
# to the changes. If they match, they are clean and should be deleted.
def remove_clean_changes
original_objects = self.original_objects
changes = self.changes
original_objects.each do |original_object|
changes.each do |change|
change.destroy if (change.attribute_one == original_object.attribute_one &&
change.original_object_id == original_object.id)
end
end
end
I know I've written it wrong, but I'm looking at the documentation and can't figure out how.
My model is Quote and has three fields, body, attribution, and work, all strings. The form is intended to add a new quote to a page of quotations.
on main/index.html.erb
<%= form_for(:quote, url: {action: 'create'}) do |f| %>
<%= f.text_field :body %>
<%= f.text_field :attribution %>
<%= f.text_field :work %>
<%= submit_tag "Submit" %>
<% end %>
in main_controller.rb
def create
Quote.create(body: params[:body], attribution: params[:attribution], work: params[:work])
end
The form submits, and an entry is saved to the database -- but it's a totally blank entry. I'm not sure why. Help would be appreciated!
Three things:
The way rails forms are supposed to work, you're not meant to get body, attribution, etc independently, they should be wrapped up into a quote object. But...
In your form, your not properly binding an object to the form the way rails expects. You can read more in the documentation here: http://guides.rubyonrails.org/form_helpers.html#binding-a-form-to-an-object. You could also generate a fake scaffold rails generate scaffold HighScore game:string score:integer to generate a fake model and see an example of how it's supposed to work. The default scaffolding even has simple examples of how to deal with save errors.
Finally, as #Paven suggested, when you get confused, be sure to look at what's going on in your log - i.e. what params are being posted to your create action. That is always helpful and a good way to diagnose problems quickly.
Your form does't need the action argument. The form_for helper uses ActiveRecord objects to determine the path, meaning as long as you build your object correctly, you won't need to determine your path individually:
<%= form_for #quote do |f| %>
Secondly, you'll want to look at your create method:
#app/controllers/quotes_controller.rb
def new
#quote = Quote.new
end
def create
#quote = Quote.new(quote_params)
end
private
def quote_params
params.require(:quote).permit(:body, :attribution, :work)
end
The problem is you're not sending an ActiveRecord object to your form_for helper. You can read the explanation here:
In Rails, this is usually achieved by creating the form using form_for
and a number of related helper methods. form_for generates an
appropriate form tag and yields a form builder object that knows the
model the form is about. Input fields are created by calling methods
defined on the form builder, which means they are able to generate the
appropriate names and default values corresponding to the model
attributes, as well as convenient IDs, etc. Conventions in the
generated field names allow controllers to receive form data nicely
structured in params with no effort on your side.
In order to get the form working correctly, you need to be able to provide a valid ActiveRecord object (#variable), which the helper can use to determine the url etc
My code above helps you provide a new ActiveRecord variable, and allows you to use it in the form. This should allow the form_for method to send your data to the create method, which will then create & save an object in the db for you
I am an newbie. I have read the API documentation. But still don't understand how form_for works.
Firstly, from Ruby on Rails Tutorial, the form for follow button:
<%= form_for(current_user.relationships.build(followed_id: #user.id)) do |f| %>
<div><%= f.hidden_field :followed_id %></div>
<%= f.submit "Follow", class: "btn btn-large btn-primary" %>
<% end %>
I understand current_user.relationships.build(followed_id: #user.id) means a new record. But why can we not just submit and trigger controller to save the record without hidden_field? Why do we still need to post followed_id to controller?
Secondly, in hidden_field, what does :followed_id means? I believe that is a symbol, i.e. it equals only "followed_id" not a variable of id. If that is only the name of the input field, then what is its value?
Thirdly, how does form_for know where the submission should be sent to? Which controller and action the form_for will post to?
Fourth, how does params work with form_for? In this follow button case, params[:relationship][:followed_id] will return #user.id in controller. How does it know the first hash attribute is :relationship? We have neither mentioned form_for :relationship nor form_for #relationship.
I know these questions can be very dumb, but I am really stuck. Any help will be appreciated.
I didnt do that tutorial so mind me if i dont answer directly to your question.
Take a look at the rails guide about form helpers and it explains in details your questions, probably in a more articulate way than i can.
form_for(path/to/your/controller/action) is a helper method to create HTML form elements with the url path to the POST or GET request. The helper knows if it should be a new record or an update record based on what you are asking to do in your controller action.
For example
In your controller
def new
#my_instance_variable = Myobject.new
end
In your view new.html.erb
<%= form_for #my_instance_variable do |f| %>
...
<% end %>
In your case the logic was directly written in the helper and you could also directly write
<%= form_for Myobject.new %>
Both will result with the following html
<form action="/myobjects/new" method="post">
# in this case rails knows its a `POST` request because the route new action
# is by default a POST request. You can check these routes and their request
# by using `rake routes` in terminal.
Then the hidden_field is another helper to contain a value, in your case the #user.id that will be passed as parameter then saved as a Create or update action for the given object. The reason it doesnt add the value in the hidden field tag is because you already have a model association that knows the id of user since the link of form uses the build method with user id.
Last part you need to understand the form_for link logic
current_user.relationships
# implies the association of the current_user has many relationships
current_user.relationships.build
# .build is a method to populate a new object that can be save as a new record
# means you will create a new relationship record by populating the user_id
# column with the current_user.id and the followed_id with the target #user.id
After reading the book The Rails 4 Way, I understand form_for better now.
11.9.1.5 Displaying Existing Values.
If you were editing an existing instance of Person, that object’s attribute values would have been filled into
the form.
in this way, when we build the relationship by usingcurrent_user.relationships.build(followed_id: #user.id), the relationship instance will be created and gain attribute followed_id. So that, instead of "creating" a relationship, we are actually editing the relationship by the form.
Then Rails will know you are editing and load the existing attribute "followed_id" to the field. Therefore, we don't need to assign value to the field like using f.hidden_field :followed_id, value: #user.id.
And the reason why we have to use a field to pass followed_id to params is because HTTP server is stateless, it doesn't remember you are creating a relationship with which user.
One of the advantages of writing form_for current_user.relationships.build(followed_id: #user.id) instead of standard form_for #relationship is we don't need to write "if-condition" in controller like this:
unless current_user.nil?
if current_user.following?(#user)
#relationship=current_user.relationships.find_by(followed_id: #user.id)
else
#relationship=current_user.relationships.new
end
end
params will be sent to the controller which belongs to the instance's model. "post" method will go to action create, "delete" will go to destroy, "patch" will go to update, etc.
params will be a hash with another hash inside like { instace_name: { field_1: value1, field_2:value2 } } or full params as below
Parameters: {"utf8"=>"✓",
"authenticity_token"=>"afl+6u3J/2meoHtve69q+tD9gPc3/QUsHCqPh85Z4WU=",
"person"=>{"first_name"=>"William", "last_name"=>"Smith"},
"commit"=>"Create"}
I have a user view and a rental view.
In my rental view im trying to show the current users name. I think I am pretty close but I can't work out this last bit.
This returns all of my users in a select list
<%= f.select :user_id, User.find(:all).collect {|t|
[t.user_name, t.id]} %>
This returns my current users ID
<%= f.number_field :user_id %>
So I thought I could do something like
<%= f.select :user_id, User.find(:user_id).collect {|t|
[t.user_name, t.id]} %>
Which I would want to only return the current user in a select list with their id as the value and their name in the list. If I do the above it tells me
Couldn't find User with id=user_id
So user_id is being passed as a literal string but I want to pass the user_id variable which should be somthing like 10. I don't know how to pass the user_id as a variable.
I'm fairly new to ROR, I might be going about this the completely wrong way. Any help is much appreciated.
I am assuming you have a rental object, for which you show the form, I assume it is an instance variable #rental, furthermore I assume that inside your Rental class there is the following relation
class Rental
belongs_to :user
end
Then you could just write the following:
f.select :user_id, [[#rental.user.user_name, #rental.user.id]]
Hope this helps.
On a related but less important note: it is really weird to have a column called user_name for a user: I would call that column just name, since it is part of a user anyway.
find() wants a variable, not a symbol. And :all probably isn't what you want. You should write a method in your controller like:
def user(u)
#user = User.find(u)
end
Then call the method in the view or whatever like (I don't know exactly what you're trying to do here):
<% user(current_user.id) %>
Then you'll have a #user object with which you may play, i.e.:
<%= f.select :user_id, [[#user.name, #user.id]] %>
I think you should be able to do:
<%= f.select :user_id, User.find(f.object.user_id).collect {|t| [t.user_name, t.id]} %>
This does seem a little odd to me though. I'd have thought either:
Your object has a proper association to the relevant user, in which case you should be able to do f.object.user.user_name and f.object.user.id.
If you genuinely want the currently logged in user, you should probably be asking your authentication framework/code for the reference. E.g. if you were using Devise, it would be current_user.
As an aside, I don't really understand why you want a select list just containing the current user - is that definitely what you're trying to achieve, or have I misunderstood?
I am new to rails, but not to programming or databases.
A BETTER PHRASING OF MY QUESTION IS IN MY ANSWER BELOW.
For simplicity in this example, I have 3 models:
User
Subscription
Default_Subscription
User has_many Subscriptions
Subscription belongs_to User
Default_Subscription has_many Subscriptions
Subscription belongs_to Default_Subscription
Default_Subscription is a pre-populated table with certain types of subscriptions.
During the subscription process, the default subscriptions are listed at one point, and there
is a quantity box alongside each one.
The user enters the quantities for each subscription and hits submit to continue on.
My question is:
How would one go about creating a new subscription for each quantity in a number form?
So you would have a list something like so:
<ol>
<%= each subscription with quantity box %>
</ol>
<%= button_to %>
When the user hits the button, how do you add up the quantity from each box and add a new subscription for each one? Do I have to use javascript to get the numbers? Do I somehow use rails forms even though this quantities are not associated with any specific database field? Any recommendations or pointing me in the right direction to figure this out on my own would be great.
This form box IS NOT A FIELD FOR ANY MODEL, it's a count for an association. Let me rephrase: Each quantity in the form boxes represent the number of NEW Subscriptions to be created. Each of these subscriptions BELONGS_TO 1 DEFAULT_SUBSCRIPTION. In essence, the number represents the number of new subscriptions ASSOCIATED WITH THAT DEFAULT SUBSCRIPTION.
I'm using rails 3.2.1, and ruby 1.8.7
Thank you
Not sure I totally understand your description, but I'll take a shot.
Use the 'form_for' function to build your form, based on an instance of #default_subscription (established in the "new" action in your controller). If there are default values in #default_subscription, will show in the fields and the user can change them as they see fit. (this assumes your DefaultSubscription model has three attributes: sub1, sub2 and sub3.)
<%= form_for #default_subscription do |f|
<%= f.label :sub1 %><br />
<%= f.number_field :sub1 %>
<%= f.label :sub2 %><br />
<%= f.number_field :sub2 %>
<%= f.label :sub3 %><br />
<%= f.number_field :sub3 %>
<% end %>
When the user clicks the submit button the contents of the form with we assembled into a hash and passed into your controller's "update" action via params[]. You can extract the subscription hash like this:
user_subscription = params[:default_subscription]
At this point you have all the numbers that the user entered into the fields in the user_subscription hash. You can now parse the hash to extract the numbers, do your math, and then create the appropriate subscriptions per the user's input. (one note: the numbers could be strings and you might need to convert them back to integers as I've shown below.)
For example, to total all the subscription values and save that total into a user's subscription:
total = 0;
user_subscription.each do |key, value|
total += value.to_i
end
new_sub = current_user.subscription.new
new_sub.total = total
new_but.save
As I said, I don't understand your description clearly, so this might not be germane, but hope it is close to what you were looking for.
Good luck.
I have figured out one way, and reading my original post again, the whole thing is really confusing because I didn't know how to say exactly what I was trying to accomplish. I must say a lot of the reason I was confused is because the form I wanted did not correspond to any model, just an association count, which is ultimately a basic html form if you want to create a bunch of new objects without having their attributes yet. I'll first clarify then show my solution.
Clarification:
I have 2 Tables:
Subscription
Default_Subscription (Pre-Populated)
Subscription belongs_to Default_Subscriptions
Default_Subscription has_many Subscriptions
A User is subscribing to my website. This process is a step by step: not everything happens on the same page.
This all happens in a subscribe_controller. Each action corresponds to a step in the process.
One of the actions is default_subscriptions. This action lists the Default_Subscriptions a User can choose from, except they do not just choose, they can enter an amount for each type of Default_Subscription they'd like.
When the Default_Subscriptions are listed on the default_subscriptions page, I wanted a form with an html number input alongside each of these Default_Subscription. When the form is submitted via a next button, I had no idea how to gather the quantities from each html input and create an array of Subscription.new, with each Subscription's default_subscription_id corresponding to the proper Default_Subscription.
One Possible Solution:
def default_subscriptions
#def_subscriptions = Default_Subscription.all
end
Lets say the page I want proceed to after all the quantities are entered on the default_subscriptions page is review_subscriptions.
Here's what I did to create the proper form to proceed to the next action in the controller:
<%= form_tag( {:controller => 'subscribe', :action => 'review_subscriptions'}, :method => 'post' ) do %>
<ol>
<% #def_subscriptions.each do |ds| %>
<li>
<%= ds.name + ' ' %>
<%= number_field_tag("subscription_counts[#{ds.id}]") %>
</li>
<% end %>
</ol>
<%= submit_tag('Next') %>
<% end %>
The trick here is that string passed to the number_field_tag. By placing a single set of square brackets at the end of the string for a field_tag method parameter, the part before the brackets is the name of the hash, and the thing in the brackets is a key in the hash, and the submit button causes the corresponding value for each key to be the value of the field. Pretty cool!
The parameters passed to the next action would contain a hash called subscription_counts, and iterating through this hash would give a corresponding new subscription amount for each default_subscription_id. Like so:
def review_subscriptions
subscription_counts = params[:subscription_counts]
subscription_counts.each do |id, amount|
counter = Integer(amount)
until counter == 0
new_subscription = Subscription.new
new_subscription.default_subscription_id = Integer(id)
#subscriptions << new_subscription # #subscriptions is an instance variable
counter -= 1
end
end
end
I'd just like to point out, the more I work with them, the more I love them; I love Rails, and I love Ruby. They are super fun and classy. An until loop... how cool is that? If you have other solutions, now that my question is more obvious, please chime in! I know others out there are trying to find some slick ways to create multiple new objects in a one to many association with a single post call like this. Technically my objects aren't saved in the database yet, but that wouldn't be to hard now.
The main reference which helped me the most in reaching this solution was:
http://guides.rubyonrails.org/form_helpers.html
If you are new to rails, and confused about forms, read this. I feel like a master now. Rails devs are really good at documenting things!