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?
Related
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.
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 %>
I am calling a random Post and allowing users to +1 or -1 the post before loading another post. My model generates a random record at the URL /posts/random using the following.
Post.rb // Model
def self.find(*args)
if args.first.to_s == "random"
Post.find :first, :offset => rand(Post.count)
else
super
end
This code generates a random post when the user visits posts/random. However, I also defined a thumbs_up and thumbs_down field in the database that correspond to a thumb_up and a thumb_down image that when clicked, need to +1 or -1 the value in the database, before redirecting to another /posts/random. My understanding is that to do this I need to invoke the PUT update method, however, since my URL is posts/random instead of posts/1, how can I do this? Do I need to alter my routes?
First thing is that you'd need is an instance variable representing the random post so that you could use it in the thumbs up and thumbs down links. Then you need to make sure that those links look something like this:
<%= link_to "Thumbs Up", post_path(#post, thumbs_up: 1), method: :put %>
<%= link_to "Thumbs Down", post_path(#post, thumbs_down: 1), method: :put %>
That way, when in your update action for your posts controller, you can do something like this:
#post.update_attributes(thumbs_up: #post.thumbs_up + params[:thumbs_up],thumbs_down: #post.thumbs_down + params[:thumbs_down] )
That is only a start, but I think that should get you going in the right direction.
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
I have a calendar_date_select in a view that shows a table listing all the information on a certain phone. I want to add a To: and From: date range that a user can select and update the table in the view. The structure is like this:
Usage Controller
Detail action in the usage controller that shows the call history from a certain phone.
Inside detail I want the To and from fields with a refresh button.
What is exactly happening in this code:
<% form_for :date_range do |f| %>
<%= f.calendar_date_select :start, :time => true %>
<%= f.calendar_date_select :end, :time => true %>
<%= f.submit "Submit" %>
<% end %>
Does this pass a hash to the usage controller and look for a date_range method? My current route looks like this
usage/detail/id-of-phone
I would like it to look something like this:
usage/detail/id-of-phone#start-end
So I could then (I think) extract the start and end dates from the params with just params[:start] and params[:end]. Am I doing this right, or is there a better way to get the desired result that I want.
I haven't used the calendar_date_select plugin, but you should be getting the parameters back already.
params[:date_range][:start]
params[:date_range][:end]
What you want is the url or the smart solution to get the params?
Please set the routes.rb for the url. Or you can make many method in the 'DataRange' model.
As many programmers using, save many dates in the model. But making us terrible is using the params smartly.
Such as
class Model
def start
......
end
def end
......
end
end
You can't get the params by params[:start] if you pass the params by the form. You can see the form's html for detail.
Please use the
params[:...][:start]