Rails: Preserving GET query string parameters in link_to - ruby-on-rails

I have a typical search facility in my app which returns a list of results that can be paginated, sorted, viewed with a different records_per_page value, etc. Each of these options is controlled by parameters in the query string. A simplified example:
/search?q=test&page=2
Now say I need to display a set of links that set records_per_page value to 10, 20, 30. Each link must include the existing query parameters, which can be a very long set, plus a new per_page parameter.
/search?q=test&page=2& ... &per_page=10
/search?q=test&page=2& ... &per_page=20
/search?q=test&page=2& ... &per_page=30
Is there an easy way to do it with just link_to helper or I need to parse and reproduce the query string from previous request somehow?

link_to 'Link', request.query_parameters.merge({:per_page => 20})

link_to 'Link', params.merge({:per_page => 20})

The simplest way to merge the new params with the query parameters and NOT with all parameters (including those obtained through the path) is to merge with request.query_parameters
link_to 'Search', search_path(request.query_parameters.merge({ per_page: 20 }))
Otherwise you end up with query strings duplicating the path parameters, for example ?action=index&controller=products&foo=bar instead of ?foo=bar.

If you want to keep existing params and not expose yourself to XSS attacks, be sure to clean the params hash, leaving only the params that your app can be sending:
# inline
<%= link_to 'Link', params.slice(:sort).merge(per_page: 20) %>
If you use it in multiple places, clean the params in the controller:
# your_controller.rb
#params = params.slice(:sort, :per_page)
# view
<%= link_to 'Link', #params.merge(per_page: 20) %>

You can just throw elements of the params hash at link_to. Like
link_to "some_other_link", "/search", :page => params[:page]

This works if the links you are processing aren't given to you by request.params.
require 'rack/utils'
require 'uri'
def modify_query url, options={}
uri = URI(url)
query_hash = Rack::Utils.parse_query(uri.query)
query_hash.merge!(options)
uri.query = Rack::Utils.build_query(query_hash)
uri.to_s
end
puts modify_query('/search?q=test&page=2&per_page=10', 'per_page' => 20)
puts modify_query('/search?q=test&page=2', 'per_page' => 30)
# Outputs
# /search?q=test&page=2&per_page=20
# /search?q=test&page=2&per_page=30

What about
<%= link_to 'Whatever', :overwrite_params => { :pear_page => 20 } %>
?

A bit late i know..
If your using this as a way to filter search results have a look at my helper :)
This automagicly removes all blank and unneeded params and add the class "selected" if all of it's new params were already set.
def search_to s, args={}
selected = 0
args.each do |k, v|
selected = selected + 1 if params[k] == v.to_s || ( params[k].nil? && v.blank? )
end
if #search_params_base.nil?
#search_params_base = request.parameters.clone
#search_params_base.delete(:action)
#search_params_base.delete(:controller)
#search_params_base.delete(:page)
#search_params_base.delete_if{|k, v| v.nil? || v.blank?}
#search_params_base.delete(:utf8) if #search_params_base[:keywords].nil?
end
search_params = #search_params_base.merge(args)
search_params.delete_if{|k, v| v.nil? || v.blank?}
link_to s, search_path + '?' + search_params.to_param, :class => selected == args.length ? 'selected' : nil
end
You can then just use this in your view:
search_to '$80 to $110', :price => 80..110
Or in your case:
search_to '30 per page', :page => params[:page], :per_page => 30

Related

Rails 4 Strong Params with multiple objects and integer keys

I'm submitting a form with 2-4 objects at once, depending on how many the parent has. I realize that this is probably unconventional, but I really wanted the user to be able to edit all of the objects at once on one form. On my form, I'm doing:
<%= simple_fields_for "derps[]", derp do |f| %>
<% end %>
Then I'm doing this in the controller:
def update
#derps = []
#rejects = []
derps_params.each do |key, hash|
derp = Derp.find(key)
derp.assign_attributes(hash)
#rejects << derp unless derp.save
end
if #rejects.empty?
redirect_to #parent, flash: {success: 'Derps were successfully updated.'}
else
#derps = #rejects
render :edit
end
end
Lets say there are two objects - the params are coming through as:
"derps"=>{"1"=>{"attribute"=>"39", "another_attribute"=>"serp", "a_third_attribute"=>"yerp"}, "2"=>{"attribute"=>"30", "another_attribute"=>"49", }}
I had this working in Rails 3 without strong params. I'm upgrading to rails 4 and I'm struggling with how to get this working - I keep getting "Unpermitted parameters: 1, 2"
I'm assuming I need to do something like:
def mashes_params
params.require(:derps).permit(
id: []
or
def mashes_params
params.require(:derps).permit(
:id,
Something along those lines, but I've tried it every way I can think of without luck.
Any ideas here?
I've found that the command line is immensely helpful for debugging Strong Parameters in Rails 4. Here's how I tested your problem in the console:
rails c # From within your project directory, short for 'rails console'
params = ActionController::Parameters.new( { derps: { 1 => { attribute: 39, another_attribute: "serp" }, 2 => { attribute: 30, another_attribute: 49 } } } )
params # To make sure that the object looks the same
permitted = params.require( :derps ).permit( 1 => [ :attribute, :another_attribute ], 2 => [ :attribute, :another_attribute ] )
permitted # To see what you'd get back in your controller
Hopefully with this tool, you'll be able to debug anything that my answer didn't provide more easily than trial and error.
Final Edit (hopefully):
Had to rethink this from the ground up. I came to the conclusion: Since :id works as a wildcard, but is not allowed as the key of the hash, why not always make the keys 1-4, so I can whitelist them explicitly, then get the ID from a key-value in the hash, much like is done in traditional form nesting? Thats how I ended up solving it. Here's the final implementation that I have working:
<% i = #parent.derps.index(derp) + 1 %>
<%= simple_fields_for "derps[#{i}]", derp do |f| %>
<%= f.hidden_field :id, value: derp.id %>
<%= render "rest_of_the_fields" %>
<% end %>
Then in the controller:
def update
#derps = []
#rejects = []
derp_params.each do |key, hash|
derp = Derp.find(hash.delete("id"))
derp.assign_attributes(hash)
#rejects << derp unless derp.save
end
if #rejects.empty?
redirect_to #parent, flash: {success: "Derps updated successfully."}
else
#derps = #rejects
render :edit
end
end
Then here are the strong params:
def derp_params
p = [:id, :attribute_1, :another_attribute, ...]
params.require(:derps).permit(
"1" => p, "2" => p, "3" => p, "4" => p
)
end
Phew. Hope this helps someone.
The absolute best solution I've seen is here:
def product_params
properties_keys = params[:product].try(:fetch, :properties, {}).keys
params.require(:product).permit(:title, :description, properties: properties_keys)
end
I made one more change to iterate through the unnamed keys since my property_keys have more nested keys and values:
response_keys = params[:survey][:responses].try(:fetch, :properties, {}).keys
params.require(:survey).permit(responses: response_keys.map {|rk| [rk => [:question_id, :answer_id, :value]]})
Here is the approach I am currently using. You can permit each nested params one by one like this:
params = ActionController::Parameters.new(
"derps" => {
"1" => {
"attribute" => "39",
"another_attribute" => "serp",
"a_third_attribute" => "yerp"
},
"2" => {
"attribute" => "30",
"another_attribute" => "49"
}
}
)
# => <ActionController::Parameters {"derps"=>{"1"=>{"attribute"=>"39", "another_attribute"=>"serp", "a_third_attribute"=>"yerp"}, "2"=>{"attribute"=>"30", "another_attribute"=>"49"}}} permitted: false>
params.fetch(:derps).map do |i, attrs|
[
i,
ActionController::Parameters.new(attrs).permit(
:attribute,
:another_attribute,
:a_third_attribute,
)
]
end.to_h.with_indifferent_access
#=> {"1"=><ActionController::Parameters {"attribute"=>"39", "another_attribute"=>"serp", "a_third_attribute"=>"yerp"} permitted: true>, "2"=><ActionController::Parameters {"attribute"=>"30", "another_attribute"=>"49"} permitted: true>}
Here is a sort of dirty way of accomplishing this which builds on the answer above by Greg Blass
This can handle an infinite number of indexes with nested params
def foo_bar_params
num_keys = params[:foo_bars].keys.size
the_params = [:id, :attr1, :attr2, :another]
permit_hash = {}
i = 0
while i < num_entries
permit_hash[i.to_s] = the_params
i += 1
end
params.require(:foo_bars).permit(permit_hash)
end
Im sure there is a fancier way to do this, but this way is readable and I can easily tell what is going on...and most importantly it works

DRY and Elegant way to represent all search combinations without growing exponentially?

Right now I can search the following
1) leaving_from location
2) going_to location
3) leaving_from &
going_to location
if params[:leaving_from].present? && params[:going_to].present?
#flights = Flight.where(:source => params[:leaving_from]).where(:destination => params[:going_to])
elsif params[:leaving_from].present?
#flights = Flight.where(:source => params[:leaving_from])
elsif params[:going_to].present?
#flights = Flight.where(:destination => params[:going_to])
end
Is there a dry way to represent this code above? Basically its a for search function compromised of 2 drop down search boxes. One for leaving from location and another for going to location. With the option of narrowing it down by both locations or just one location.
It works fine now but it isn't very scalable. If I added more search parameters say price and time, it would grow exponentially in order to be able to represent all the states.
For example if I added price my new combinations would be
1) leaving_from location
2) going_to location
3) leaving_from &
going_to location
4) price
5) leaving_from location & price
6) going_to location & price
7) leaving_from location & going_to location & price
I need help to figure out a better way to represent this, or else it would make my controller incredibly bloated.
EDIT FORM CODE --
=form_tag '/flights', :method => :get
%h4
Leaving From:
=select_tag 'leaving_from', content_tag(:option,'select one...',:value=>"")+options_for_select(#flights_source, 'source'), { :class => 'form-control' }
%h4
Going To:
=select_tag 'going_to', content_tag(:option,'select one...',:value=>"")+options_for_select(#flights_destination, 'destination'), { :class => 'form-control' }
%h4=submit_tag "Search", :name => nil, :class => 'btn btn-success btn-md btn-block'
In place of using leaving_from or going_to use source and destination instead and Move all the required parameters under a key, e.g., this solution will work for any no. of keys
'required' => { 'source' => value, 'destination' => value, 'price' => value }
Now in the controller define this method in private
def get_flights(params)
possible_combination = []
conditions = {}
key_array = params['required'].keys
1.upto(key_array.length) { |i| possible_combination + key_array.combination(i).to_a }
possible_combination.reverse.each do |comb|
if comb.collect{ |key| params['required'][key].present? }.inject(:&)
comb.map { |key| conditions[key] = params['required'][key] }
break
end
end
Flight.where(conditions)
end
Call this method from any action
#flights = get_flights(params)
Hope this works! Its an overall idea to make this thing dynamic, you can refactor the code according to your need!
First things first: your code does not do what you think it does, since there is no way for it to execute the third if (every time the third if is true, the first if is as well). On to your question:
#flights = Flight
#flights = #flights.where(:source => params[:leaving_from]) if params[:leaving_from].present?
#flights = #flights.where(:destination => params[:going_to]) if params[:going_to].present?
Or
conditions = {}
conditions[:source] = params[:leaving_from] if params[:leaving_from].present?
conditions[:destination] = params[:going_to] if params[:going_to].present?
#flights = Flight.where(conditions)
How about using ransack which adds your rails to search function very easily.
You just write below, if you use ransack.
# View (Search Form)
<%= search_form_for #q do |f| %>
From: <%= f.text_field :leaving_from_cont %>
To : <%= f.text_field :going_to_cont %>
Price:
<%= f.text_field :price_gteq %> 〜 <%= f.text_field :price_lteq %>
<%= f.submit %>
<% end %>
# Controller
def index
#q = Flight.ransack(parmas[:q])
#flights = #q.result(distinct: true)
end
If a user don't input any fields, ransack don't use the non-input fields value. It means don't add WHERE conditions in DB.
column_name_cont means contain (Like in DB).
column_name_eq means equal (== in DB).
column_name_gteq means greater than equal (<= in DB).
column_name_lteq means less than equal (>= in DB).
etc...
Also you can sort the search result easily by using sort_link methods of ransack.
Please look in ransack.
I was not able to get #RSB's code to work but I was able to use his example to create a method that did work. I call the below code in my action.
#flights = get_flights(search_params)
The search_params method is as follows:
def search_params
params.permit(:leaving_from, :going_to)
params_hash = {'required' => { 'source' => params[:leaving_from], 'destination' => params[:going_to]}}
end
And finally the get_flights method is:
def get_flights(params)
possible_combination = []
conditions = {}
key_array = params['required'].keys
possible_combination = (possible_combination + key_array.combination(key_array.length).to_a).flatten
possible_combination.each do |comb|
conditions[comb] = params['required'][comb] if params['required'][comb].present?
end
Flight.where(conditions)
end
I am still pretty new to ruby and rails so any feedback or suggestions for improvements would be greatly welcome. Thanks!

Create a link for next page in rails

I'm using the Twilio API in a rails app to show a user a list of their recordings. Say a user has 11 recordings total, and I'm showing them 3 per page.
twilio_controller.rb
def calls
#user = current_user
#account_sid = #user.twilio_account_sid
#auth_token = #user.twilio_auth_token
#page_size = 3
#page = params[:page_id] || 0
#sub_account_client = Twilio::REST::Client.new(#account_sid, #auth_token)
#subaccount = #sub_account_client.account
#recordings = #subaccount.recordings
#recordingslist = #recordings.list({:page_size => #page_size, :page => #page})
end
calls.html.erb
<% #recordingslist.each do |recording| %>
<tr>
<td><%= recording.sid %></td>
</tr>
<% end %>
<%= link_to "Next Page", twilio_calls_path(#page + 1) %>
routes.rb
#twilio routes
post 'twilio/callhandler'
get 'twilio/calls'
match 'twilio/calls' => 'twilio#page', :as => :twilio_page # Allow `recordings/page` to return the first page of results
match 'twilio/calls/:page_id' => 'twilio#page', :as => :twilio_page
Paging info is built into the Twilio response such that
#recordingslist.next_page
gives me the next 3 recordings (verified in rails console). How do I link to that so that when a user clicks the link, the table loads the next 3 results?
Thanks!
You can use a gem like Kaminari for Pagination.
https://github.com/amatsuda/kaminari
I would recommend utilizing the paging functionality that ships with twilio-ruby. According to the docs:
ListResource.list() accepts paging arguments.
Start by create a route for your Twilio list view. Make sure you can pass a page_id parameter – this is how your controller action will know which page to render:
# config/routes.rb
match 'recordings/page/:page_id' => 'twilio#page', :as => :twilio_page
match 'recordings/page' => 'twilio#page', :as => :twilio_page # Allow `recordings/page` to return the first page of results
Then, in the page action, pull the page_id parameter (or set if to 1 if there is no page_id, and pass the page_number and page_size as arguments to #recordings.list:
# app/controllers/twilio_controller.rb
def page
page_size = 3
#page = params[:page_id] || 1
#sub_account_client = Twilio::REST::Client.new(#account_sid, #auth_token)
#subaccount = #sub_account_client.account
#recordings = #subaccount.recordings
#recordingslist = #recordings.list({:page_size => page_size, :page => page)})
end
Finally, in your view, pass the page number to twilio_page_path in your link_helper – just make sure to adjust the page number accordingly (+1 for the next page, -1 for the previous page:
# view
<%= link_to "Next Page", twilio_page_path(#page.to_i + 1) %>
<%= link_to "Previous Page", twilio_page_path(#page.to_i - 1) %>
Note that – if you're at the start or end of your list – you may inadvertently end up passing an invalid page_id. Therefore, you may want to implement some exception handling in your page controller action:
# app/controllers/twilio_controller.rb
def page
begin
#page = params[:page_id] || 1 # If `page_id` is valid
rescue Exception => e
#page = 1 # If `page_id` is invalid
end
# Remaining logic...
end

How to make optional :conditions for a find

Hello I have the followong struggle in my head. I want a text-field in which the use can type in some parameters, which will be used as filter-criteria for the :conditions hash in my find method.
I have created a helper, with takes an option and merge the hash to the options:
In my controller:
#bills = adminbill_filter(:limit=>params[:limit] || 50,:offset=>params[:offset] || 0, :conditions=>params[:options])
In my helper:
def link_to_with_current(text, link, condition, *args)
options = args.first || {}
options[:class] = condition ? 'current' : nil
link_to text, link, options
end
In my view:
<%= text_field :filter ,:criteria, :class=>'roundRect',:id=>'name', :value=>12009%>
<%= button_to_with_filter 'Start Filter', 'index', :filter_condition=>true, :options=>{:id=>81}%>
Is it somehow possible to pass the value of text_field into the :option=>{...} of the button_to_with_filter? I find this solution (if it is working) quite unhandy. Your comments are as always very helpful.
Greetings
Matthias
It seems kind of terrifying to put in the contents of user-submitted params without vetting them in any capacity. You're probably going to run into all kinds of exceptions if the data doesn't come in as expected, or is formulated to be malicious.
I've found it's often easier to use a chained scopes approach:
def index
bills_scope = Bill
# Use an example Bill.with_id scope
if (params[:with_id])
bills_scope = bills_scope.with_id(params[:with_id])
end
# Repeat as required
# Finally, use the scope to retrieve matching records
#bills = bills_scope.paginated
end
Using something like will_paginate can help with your offset and limit values.
If the text field and button were encapsulated in a form, and the button was the submit button, the text field's value would automatically be brought into the params hash. Then you wouldn't have to deal with it. I can't recall at the moment the exact Rails helpers that will do this for you, but you want the resulting form to probably be something like this:
<% form_for :options, :url => {:action => :index}, :html => { :method => :get } do |f| %>
<%= f.text_field :filter ,:criteria, :class=>'roundRect',:id=>'name', :value=>12009%>
<%= f.submit 'Start Filter' %>
<% end %>
Which may change some, since I don't know the underlying code behind your methods.
Otherwise, the only thing I can think of is using a Javascript event on the button that grabs the value of the text field before it submits.
Thanks for your help, I came across named_scope and solved the problem with the following code:
Bill model:
class Bill < ActiveRecord::Base
# named_scope werden fuer Filterfunktionen bei Adminbill benoetigt
named_scope :standard, :order => "created_at DESC"
named_scope :limit, lambda {|*args| {:limit=>(args.first)|| 50}}
named_scope :offset, lambda {|*args| {:offset=>(args.first || 10)}}
named_scope :paid, :conditions=>"paid IS NOT NULL"
named_scope :not_paid, :conditions=>{:paid=>nil}
named_scope :test_bill, :conditions => {:test_bill=>true}
named_scope :no_test_bill, :conditions => {:test_bill=>false}
named_scope :find_via_bill_id, lambda {|*args|{:conditions=>{:id=>(args.first || 210)}}}
named_scope :find_via_email, lambda {|*args| {:conditions=>{:buyer_id=>args.first}}}
controller:
def index
logger.debug "The object is #{current_user}"
if params[:filterInput] != nil && !params[:filterInput].empty?
filter_array = params[:filterInput].split('&')
bill_scope = Bill.scoped({})
bill_scope = bill_scope.standard
# Filtere via Regexp-Matching die Zahlen der Eingabe heraus
filter_array.each do |el|
if el =~ /limit\([0-9]+\)/
number =
bill_scope = bill_scope.limit(el.scan(/\d+/)[0])
elsif el =~ /offset\([0-9]+\)/
bill_scope = bill_scope.offset(el.scan(/\d+/)[0])
elsif el == 'paid'
bill_scope = bill_scope.paid
elsif el == 'not_paid'
bill_scope = bill_scope.not_paid
elsif el == 'test_bill'
bill_scope = bill_scope.test_bill
elsif el =~ /find_via_bill_id\([0-9]+\)/
bill_scope = bill_scope.find_via_bill_id(el.scan(/\d+/)[0])
elsif el =~ /find_via_email\([A-Za-z0-9.#-]+\)/
email = el.scan(/\([A-Za-z0-9.#-]+\)/)[0]
# TODO geht bestimmt auch eleganter durch besseres Matching
email = email.gsub("(", "")
email = email.gsub(")", "")
user = User.find_by_email(email) unless User.find_by_email(email).blank?
bill_scope = bill_scope.find_via_email(user.id)
end
end
#bills = bill_scope
else
#bills = Bill.standard.limit.offset
end
And in the view:
<% form_tag(:action => 'index') do %>
<%= text_field_tag 'filterInput', nil, :size => 40 %>
<%= submit_tag 'Start Filter'%>
<% end %>
Now you can pass in the tex-field e.g.the following valid expression: paid&limits(20)
I know that the controller solution isn't very elegant but for me it was the fastest way to solve this problem.

Passing hash as values in hidden_field_tag

I am trying to pass some filters in my params through a form like so:
hidden_field_tag "filters", params[:filters]
For some reason the params get changed in the next page. For example, if params[:filters] used to be...
"filters"=>{"name_like_any"=>["apple"]} [1]
...it gets changed to...
"filters"=>"{\"name_like_any\"=>[\"apple\"]}" [2]
note the extra quotations and backslashes in [2] when compared to [1].
Any ideas? I'm attempting to use this with searchlogic for some filtering, but I need it to persist when I change change objects in forms. I would prefer not to have to store it in session.
My solution was just to re-create each of param with key-value pair:
<% params[:filters].each do |key,value| %>
<%= hidden_field_tag "filters[#{key}]",value %>
<% end %>
You actually want/need to 'serialize' a hash using hidden fields.
Add this to your ApplicationHelper :
def flatten_hash(hash = params, ancestor_names = [])
flat_hash = {}
hash.each do |k, v|
names = Array.new(ancestor_names)
names << k
if v.is_a?(Hash)
flat_hash.merge!(flatten_hash(v, names))
else
key = flat_hash_key(names)
key += "[]" if v.is_a?(Array)
flat_hash[key] = v
end
end
flat_hash
end
def flat_hash_key(names)
names = Array.new(names)
name = names.shift.to_s.dup
names.each do |n|
name << "[#{n}]"
end
name
end
def hash_as_hidden_fields(hash = params)
hidden_fields = []
flatten_hash(hash).each do |name, value|
value = [value] if !value.is_a?(Array)
value.each do |v|
hidden_fields << hidden_field_tag(name, v.to_s, :id => nil)
end
end
hidden_fields.join("\n")
end
Then, in view:
<%= hash_as_hidden_fields(:filter => params[:filter]) %>
This should do the trick, even if you have a multilevel hash/array in your filters.
Solution taken http://marklunds.com/articles/one/314
I just wrote a gem to do this called HashToHiddenFields.
The core of the gem is this code:
def hash_to_hidden_fields(hash)
query_string = Rack::Utils.build_nested_query(hash)
pairs = query_string.split(Rack::Utils::DEFAULT_SEP)
tags = pairs.map do |pair|
key, value = pair.split('=', 2).map { |str| Rack::Utils.unescape(str) }
hidden_field_tag(key, value)
end
tags.join("\n").html_safe
end
Here's how I managed to pass a parameter value through my view - that is, from View A through View B and on to the controller:
In View A (index):
<%= link_to 'LinkName', {:action => "run_script", :id => object.id} %>
In View B (run_script):
<%= form_tag :action => 'index', :id => #object %>
<%= hidden_field_tag(:param_name, params[:id]) %>
In the controller:
Just reference params[:param_name] to make use of the value.
The key transition that wasn't documented anywhere I could find is where {... :id => object.id} from View A is passed on to View B as <%... :id => #object %>, which View B then passes on to the controller as (:param_name, params[:id]) through the hidden_field_tag construct.
I didn't see this documented anywhere but after perusing several posts across several sites including this post (whose syntax provided the key inspiration), the solution finally gelled. I've seen the caveats on hidden fields pertaining to security but have found no other way to do this given my current design, such as it is.
it's because when you convert in HTML with your hidden_field_tag, the backquote is add. After when you received it like a string not a Hash.
The Hash type can't exist in HTML. You have only string. So if you want pass your hash (not recommend by me), you need eval it when you received it. But can be a big security issue on your application.
As a caveat to Vlad's answer, I had to use raw:
<%= raw hash_as_hidden_fields(:filter => params[:filter]) %>
to get it to work in Rails 3.1.1. Essentially, the text being output was being escaped, eg., "<" becoming "&lt".
Assuming the hash is strings, symbols, numbers, and arrays, you can call eval to convert the params string of the hash from the hidden_fields form back into a hash in the controller. Then the backslash escape characters for the quotes added are no longer an issue:
hash = eval(params["hash_string"].to_s)
Credit to the following article for helping identify this simple solution for my case:
How do I convert a String object into a Hash object?
Keep in mind the contents of the params should be cleaned with .require and .permit.

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