Post Params to External Site with Link_to - ruby-on-rails

I have a shop application and another site thats for a special promotion. I've used Active Resource to import products from the shop in to the promo site and added a shopping cart to add the products. However, to actually order the products I need to send the items to the shop application, creating a new cart there to finish the order.
I've made a demo 'RESTful' application to practice using xml to send data back and forth, so I'm trying to use the principles of REST for the real app. However, I need to send the products to a non-RESTful controller. Just to give you an idea of the Cart controller in the shop, here are its actions:
def index…
def add…
def checkout…
def update…
def remove…
def empty…
def apply_discount…
def remove_discount…
def apply_credits…
def remove_credits…
def stock_check…
# My action to accept items from carts in other apps
def cart_import…
And in routes.rb, the only route relating to the cart is currently
map.cart 'cart/:action/:id', :controller => 'shop/cart'
I've inherited the shop application from a previous developer, so I'd probably try to make it more RESTful if I was to make it from scratch.
Anyway, I'm pretty confident that I can get the cart to respond to XML, even without being defined with map.resources. My problem is how to send a hash of the cart items and quantities from the promo app.
To group the cart items and quantities I've collected the item's product id and quantity in to a hash:
<% #items = Hash.new %>
<% #cart.items.collect {|i| #items[i.product_id] = i.quantity} %>
Which when inspected gives the following output:
<%= Rails.logger.info #items.inspect %>
{1144=>2, 1143=>1}
So I figured to send them to the shop I could pass them in a posted link_to:
<%= link_to 'Export Cart', "http://shop.example.com/cart/cart_import", :items => #items, :method => :post %>
That doesn't seem to do anything, whereas omitting the first field appends the items to the URL in a format that looks sensible, but appears as a relative link on the promo application:
<%= link_to "http://shop.example.com/cart/cart_import", :items => #items, :method => :post %>
http://promo.example.com/cart?items[1143]=1&items[1144]=2&method=post
I'm sure the clue is in that the #items object needs to be passed in with the url, but since I can't use a named route I don't really know how to get it in there so that it is posted in the correct format.
Thanks for the help,
Gareth

the way you are passing in the parameters for the link_to method is assuming that :items is one of the link_to options, not one of the url options. this is an order of precedence issue and if you wrap your url inside parens then you can use the options available for the url_for method on your url, to build the path: http://apidock.com/rails/ActionView/Helpers/UrlHelper/url_for

You can't use a link to generate a POST request. It is turning to a GET request. Better use javascript to generate a post request on click of a button or some other event.

In the end I made a helper:
def hash_to_params(items)
result = ""
i = 0
items.each do |item|
i > 0 ? result += "&" : result += ""
result += "items[#{item[0]}]=#{item[1]}"
i += 1
end
return result
end
Then for the link I called the helper:
<%= link_to "export", "http://shop.example.com/cart/cart_import?#{hash_to_params(#items)}", :method => :post %>
Pretty ugly way of doing it, but I really can't think of anything better?
Cheers,
Gareth

Related

How to add checkbox values (client ids) to a User attribute (User.clients)

I've been struggling to get this to work following a tutorial. I've got Users that have profiles, and a Client model that, through a 'many to many' join table, establishes the relationships between the user and the clients.
What I'm trying to do is create a list of check boxes generated from the list of clients in the DB that you can tick on or off, and then when you submit it, the user will have the relationship to those clients through the join table.
It's sort of working with static data as you can see below:
/profiles/show.html.erb
<% #clients.all.each do |client| %>
<li>
<%= check_box_tag "user[client_ids][]", client.id %>
<%= client.client_name %>
</li>
<% end %>
<%= link_to 'Add Clients', '../assign_clients/' + #profile.user.id.to_s , class: 'btn btn-default' %>
Routes
get 'assign_clients/:id', to: 'users#assign_clients'
And finally in my users_controller.erb
def assign_clients
#user = User.find(params[:id])
#user.client_ids = [1,2]
redirect_to :back, alert: 'Assigned Users'
end
Obviously it's just using hard coded values of 1 and 2. What I'm not sure how to do is wrap the checkboxes in the correct form tag/simple_form (which I am using), and then with the 'submit' button, have that do the 'assign_clients' action that passes through the values.
Thank you for any help.
What I'm not sure how to do is wrap the checkboxes in the correct form
tag/simple_form (which I am using), and then with the 'submit' button,
have that do the 'assign_clients' action that passes through the
values.
In order to create a form that will trigger the assign_clients method a route needs to be setup in your routes.rb file like the following:
resources :users do
patch 'assign_clients', to: 'users#assign_clients', as: 'assign_clients'
end
This sets up a route for a user that you can use the http patch method with (ie. UPDATE). The plan is to pass the client_ids to the users controller as params from the form. I gave it a path name so that we can reference it in the form as user_assign_clients_path(:user_id)
Now that we have the route set up...using the default rails form tags you can structure the form along the lines of this:
<%= form_for #user, url: user_assign_clients_path(#user) do |f| %>
<% #clients.each do |client| %>
<li>
<%= check_box_tag "user[client_ids][]", client.id, #user.clients.include?(client) %>
<%= client.client_name %>
</li>
<% end %>
<%= f.submit "Add Clients", class: "btn btn-default" %>
<% end %>
This will create a form allowing you to post the selected clients as an array of ids to the assign_clients method.
Finally, the assign_clients method can then retrieve the client_ids from the params hash (via params[:user][:client_ids] most likely) and update the user instance (retrieved using user_id from params hash also). You will probably have to add client_ids: [] to the end of your strong parameters list for user to whitelist it - but this essentially should behave like a typical update method.
def assign_clients
#user = User.find(params[:user_id])
#user.update(user_params)
redirect_to wherever_path
end
def user_params
params.require(:user).permit(
client_ids: []
)
end
You need to understand several basic concepts, let me explain to you:
on: member routing - in order to solve your issue directly, your route should be something like:
resources :users do
post '/assign_clients/:client_id', on: :member
end
so that other than user_id, the :client_id can be also passed in as a parameter. For the details, you can read about rails guides on routing.
For the checkbox way, you need nested_attributes - http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html. So that you can achieve what u need with a simple update call on users.
You can also implement a customised logic, with the client_ids passed in as parameters. In order to learn how forms & parameters work in rails, you can build a form, submit it, and see how it goes in the rails server log.
If anything is unclear, simply comment below & I'll try to update.

I want to use one controller and html.erb files for my dynamic table. How I will do it in Ruby On Rails?

I stored all the tablename I've created to Menu table. And every time I add the table in Menu, it will automatically create a link under Menu list
see below.
I want each table in Menu to have a Listing, New, Edit, and Delete.
see below.
I have a controller prj_menus_controller, I will just pass the id of the table from Menu table.
here is the code for index and new in my controller.
Class PrjMenusController < ApplicationController
def index
#prj_menus = Menu.find(params[:id]).tablename.singularize.classify.constantize.all
end
def new
#prj_menu = Menu.find(params[:id]).tablename.singularize.classify.constantize.new
end
def create
#prj_menu = Menu.find(params[:id]).tablename.singularize.classify.constantize.new(prj_menu_params)
if #prj_menu.save
redirect_to :action => 'index'
else
render :new
end
end
private
def prj_menu_params
params.require("HERE IS MY PROBLEM").permit(:name)
end
end
and in my
new.html.erb
<%= simple_form_for (#prj_menu),:url => prj_menus_path, :method => :post do |f| %>
<%= f.input :name %>
<%= f.submit 'Save', class: 'btn btn-primary' %>
<%= link_to "Cancel", :back, {:class=>"btn btn-default"} %>
<% end %>
I can get the list in my index.html.erb, it is working. My problem is that I don't know how to get all params when I click the submit in new.html.erb. I got this hash
{"sample1_table"=>{"name"=>"test 6"}, "commit"=>"Save","controller"=>"prj_menus", "action"=>"create"}
It is correct but I don't know what to put in my controller. I tried this params.require(["#{#prj_menu}"]).permit(:name), it creates new record but params[:name] does not save.
I am still a noob to Ruby On Rails and I don't know what to search for this.
I think you are mostly confused on what parameter whitelisting does and how parameters are passed from the form to the controller.
I does not really matter if the name of the form hash matches the name of the database table. It just does in most cases since that makes the most sense. It's simply representative of the REST interface of your app.
Let's say you have a action which creates Pets:
POST /pets
And in our form we have a bunch of inputs like so:
<input name="pet[name]">
Rails will map create a params[:pet] hash { name: 'Spot' }. But we want to save the pets as an Animal.
class PetsController < ApplicationController
def new
#pet = Animal.new()
end
def create
#pet = Animal.new(pet_params)
if #pet.save
# ...
end
def pet_params
params.require(:pet).permit(:name)
end
end
Animal does not care what the params key is, it just gets a hash. But we also need to tell simple_form what parameter key we want to use since it looks at the model_name attribute.
simple_form_for(#pet, as: :pet)
Gives us pet[name] instead of animal[name].
I don't get why you are so adamant about making things so difficult for yourself though unless you are creating a database administration tool in the vein of PHP_MyAdmin. And even that case you don't even want to be altering the schema of the app database at runtime.
You are going to run into huge problems when it comes to creating effective queries for getting all the menus.

setting a dynamic link_to rails

I'm pretty new to rails and I'd like to set my links for a certain page dynamically. I have a table called "Unfinished" and it has a column called "link" (corrected from "links") I'd like to be able to call the "link" record in the view to set my link_to link path.
I am trying to do this...
<%= link_to #unfinished.link(:p => #post.id) do %> FINISH <% end %>
...but that's not working.
my controller says:
def show
#post = Post.find(params[:id])
#unfinished = Unfinished.where('progress = ?', #post.progress).last
end
and the controller logic works fine...until I try to put the #unfinished.link into link_to
Edit:
Error Message:
wrong number of arguments (1 for 0)
Model
class Unfinished < ActiveRecord::Base
end
The type of links are :
step1_path
step2_path
step3_path
I am making a multipage form that you can save partway through. Based on a value in the #post.progress column (like 1, 2, 3) the correct path to complete the post will be provided (step1_path, step2_path etc...)
try this.
<%= link_to eval(#unfinished.link.to_s) do %> FINISH <% end %>
since the link you want is actually a named route, so you will need to eval it.
but with this you wouldn't be able to be able to pass in the post id, which you will need.
If the route is the same for all records (save for what part you are on based on the progress attribute) do you even need to store it in the database? You could just make the link method return the path (that you would still need to eval).
something like
def link (post)
"step#{self.progress}_path(post.id)"
end
and then eval the link on the way back. but Not sure if that will work, just thinking out loud...
There are gems that do multi-stage forms perhaps looking into them might help?

How to hide parts of the view given a user role on Rails 4

I'm trying to hide parts of my views depending on the User role.
So let's say I want only admins to be able to destroy Products. Besides the code in the controller for preventing regular users from destroying records, I would do the following in the view:
<% if current_user.admin? %>
<%= link_to 'Delete', product, method: :delete %>
<% end %>
The previous code works, but it's prone to errors of omission, which may cause regular users to see links to actions they are not allowed to execute.
Also, if I decide later on that a new role (e.g. "moderator") can delete Products, I would have to find the views that display a delete link and add the logic allowing moderators to see it.
And if there are many models that can be deleted only by admin users (e.g. Promotion, User) maitenance of all the ifs would be pretty challenging.
Is there a better way of doing it? Maybe using helpers, or something similar? I'm looking for something maybe like this:
<%= destroy_link 'Delete', product %> # Only admins can see it
<%= edit_link 'Edit', promotion %> # Again, only admins see this link
<%= show_link 'Show', comment %> # Everyone sees this one
I found these two questions that are similar to mine, but none of them answered my question:
Show and hide based on user role in rails
Ruby on Rails (3) hiding parts of the view
I strongly recommend pundit.
It allows you to create "policies" for each model. For your Product model you might have a ProductPolicy that looks something like this
class ProductPolicy < ApplicationPolicy
def delete?
user.admin?
end
end
In your view you can do something like this
<% if policy(#post).delete? %>
<%= link_to 'Delete', product, method: :delete %>
<% end %>
If later on you want to add a moderator role, just modify the policy method
class ProductPolicy < ApplicationPolicy
def delete?
user.admin? || user.moderator?
end
end
So I kind of figured a way to move the IFs out of the view. First, I override the link_to helper in my application_helper.rb:
def link_to(text, path, options={})
super(text, path, options) unless options[:admin] and !current_user.admin?
end
Then on my views I use it as:
<%= link_to 'Edit Product', product, admin: true, ... %>
This prevents regular users from seeing admin links, but for other html tags with content inside, such as divs, tables etc., an if would still be needed.
CanCan is another gem that lets you define "Abilities" per user role.
In views you can use something like if can? :delete, #post to check if the
user may delete that specific post.
Using the CanCan and Role gems, what is still needed is a way to Check The Route and see if "current_user" has permissions to access that Route based on their role(s) - then show/hide based on that.
This saves the user clicking on things and getting told they cannot see it - or us having to write per-item "if" logic specifying what roles can see what list-items (which the customer will change periodically, as roles are changed/refined) around every single link in one's menu (consider a bootstrap menu with 50+ items nested in groups with html formatting, etc), which is insane.
If we must put if-logic around each menu-item, let's use the exact same logic for every item by checking the role/permissions we already defined in the Ability file.
But in our menu-list, we have route-helpers - not "controller/method" info, so how to test the user's ability to hit the controller-action specified for the "path" in each link?
To get the controller and method (action) of a path (my examples use the 'users_path' route-helper) ...
Rails.application.routes.recognize_path(app.users_path)
=> {:controller=>"users", :action=>"index"}
Get just the controller-name
Rails.application.routes.recognize_path(app.users_path)[:controller]
=> "users"
Ability uses the Model for its breakdown, so convert from controller name to it's model (assuming default naming used) ...
Rails.application.routes.recognize_path(app.users_path)[:controller].classify
=> "User"
Get just the action-name
Rails.application.routes.recognize_path(app.users_path)[:action]
=> "index"
And since the "can?" method needs a Symbol for the action, and Constant for the model, for each menu-item we get this:
path_hash = Rails.application.routes.recognize_path(app.users_path)
model = path_hash[:controller].classify.constantize
action = path_hash[:action].to_sym
Then use our existing Abilty system to check if the current_user can access it, we have to pass the action as a symbol and the Model as a constant, so ...
<% if can? action model %>
<%= link_to "Users List", users_path %>
<% end %>
Now we can change who can see this resource and link from the Ability file, without ever messing with the menu, again. But to make this a bit cleaner, I extracted out the lookup for each menu-item with this in the app-controller:
def get_path_parts(path)
path_hash = Rails.application.routes.recognize_path(path)
model_name = path_hash[:controller].classify.constantize
action_name = path_hash[:action].to_sym
return [model_name, action_name]
end
helper_method :get_path_parts
... so I could do this in the view (I took out all the html-formatting from the links for simplicity, here):
<% path_parts = get_path_parts(users_path); if can?(path_parts[1], path_parts[0]) %>
<%= link_to "Users Listing", users_path %>
<% end %>
... and to make this not take all day typing these per-menu-item if-wraps, I used regex find/replace with capture and wildcards to wrap this around every list-item in the menu-item listing in one pass.
It's far from ideal, and I could do a lot more to make it much better, but I don't have spare-time to write the rest of this missing-piece of the Role/CanCan system. I hope this part helps someone out.

pass value of td element to rails controller

I'm trying to pass the value of a element to a rails controller!
Currently, I have something like this:
<td id="dbname"><%= link_to db, :action => :show %></td>
This represents a row in an html table, which contains a string value, e.g. "development".
When the user clicks on the "development" link, the <%= link_to ... %> grabs the value from the current clicked and passes that to a rails controller action, in this case the show action.
How can this be achieved!?
UPDATE - generating links:
<% #dbs.each do |db| %>
<tr>
<td id="dbname"><%= link_to db, :action => :show %> </td>
</tr>
UPDATE 2:
this is my index controller:
conn = Mongo::Connection.new
#dbs = conn.database_names #this returns an array of strings (which are the names of the databases)
Now I want to be able to click on of these databases and then to pass the clicked text to the rails controller show action. I'm not sure how I would generate a custom resources path for these links... but I was contemplating of doing it using Ajax or something javascript related. Maybe get the text of clicked link using jQuery and then send an Ajax request to the rails controller with the text as a parameter!
I think that it's a strange thing what you're trying to do, but a solution could be to use javascript to append the id to the href of each link as a query string.
If you could explain a little bit what you're trying to achieve maybe we could find a better solution.
Hope it helps!
Edit:
If you have a table of links I think that you should consider them as a resource and managing them the REST way.
Your controller should have an index and show action and you should declare the links as a resource in the routes file (maybe link it's a reserved word and you will have to use a different name, I'm not sure), the index action will fetch all the links and when you render them, you could specify the link for each one with something similar to "link_path(link.id)" (remember, you should have a show action defined) in the controller you will receive the link id so you could load it with a simple "find" and pass it to the view.
I recommend you to always look for the REST way to solve a problem in ROR.
Edit 2:
Ok let's see if this works for you:
I suppose that you have a model that represent those links that you're talkin about, for example:
class DataBaseLinks < ActiveRecord:Base
end
This model with be backed up by a table in your database, if you have generated it the rails way, you will also have an id column that identify each database link.
in your controller, let's say DataBaseLinksController, you'll have:
class DataBaseLinksController < ApplicationController
def index
#dabatase_links = DataBaseLink.all
end
def show
#database_link = DataBaseLink.find(params[:id])
end
end
(I've avoided all the validations and checks).
All you have to do in your index.html.erb is:
<% #database_links.each do |database_link| %>
<%= link_to database_link.name, database_link_path(database_link.id) %>
<% end %>
This will generate all the links with the correct path to the show action (maybe the route helper is a little bit different, but not so much).
Notice also that you'll have to add into your routes.rb the following line:
resources :database_links, :only => [:index, :show]
How do you see it?
Edit 3:
(I'll delete all my edited answers when we find a correct one)
Ok I'm going to suppose that you are not using something like mongoid so you don't have active record similar objects.
Have you tried this in your view:
<% dbs.each do |dbs_name| %>
<%= link_to dbs_name, :controller => "your_controller", :action => :show, :dbs_name => dbs_name %>
<% end %>

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