I have a pretty simple rails app where users can upvote pins. The system I implemented is working well, But I would like the number of votes updated after each votes through an ajax method.
Here is my upvote system as how it is now:
in app/controllers/pins_controller.rb:
def upvote
#pin = Pin.friendly.find(params[:id])
#pin.votes.create(user_id: current_user.id)
respond_to do |format|
format.json { render json: { count: #pin.votes_count } }
end
end
in my app/views/pins/index.html.erb:
<%= link_to upvote_pin_path(pin), method: :post, remote: true do %>
<% if pin.votes.where(user_id: current_user.id).empty? %>
<span class="text-decoration: none;"><i class="fa fa-star"></i>
<% else %>
<span class="text-decoration: none;"><i class="fa fa-star" style="color:#c0392b"></i>
<% end %>
<% end %>
<span class="votes-count">
<%= pluralize(pin.votes.count, "") %>
</span>
So everytime someone upvote a pin, the vote is visible only after refreshing the page. Any ideas?
I know I should call the ajax method inside an upvote.js.erb file in my views, but that is where I am lost.
I personally prefer to avoid those messy .js.erb files, though you can certainly do it that way. Once you're making a lot of Ajax calls, though, you end up with a whole lot of files. Ryan Bates has a phenomenal screencast on this technique here.
To do it without, here's the recipe. You'll need to put a respond_to block in your controller action. Right now, now matter how the request comes in, you're redirecting to the pin path, which I'm assuming is the current path in this case, which reloads the page. That's what you're trying to avoid.
Ajax request by default come in to controllers as javascript, or js, request types. You can switch that type if you want (JSON is a popular alternative), but let's keep it simple for now. So configure the respond_to block for a js request:
# app/controllers/pins_controller.rb
def upvote
#pin = Pin.friendly.find(params[:id])
if #pin.votes.create(user_id: current_user.id)
respond_to do |format|
format.html {
flash[:notice] = "Thanks for your recommendation."
redirect_to(pin_path)
}
format.js {
#count = #pin.votes.count.to_s
render nothing: true, count: #count # anything else you put in here will be available in the `success` callback on the JQuery ajax method.
}
end
else
format.html {
flash[:notice] = "Unable to process your request. Please try again."
redirect_to(pin_path)
}
format.js {
render nothing: true # anything else you put in here will be available in the `error` callback on the JQuery ajax method.
}
end
end
Now that the controller has passed back the value, you need to retrieve it in your Ajax request:
$.ajax({
.....
success:function(data){
$('span.votes-count').text(data.count)
}
Two things (at least) won't be available to you as you're using them with this method. The flash message, and the ruby pluralization method. To get around the second one you'll need to use the Ruby pluralization in the controller and return the text you want. To get around the first one, you'll need to set up some javascript that imitates the Rails flash message technique, as well as pass the flash message back to the Ajax call.
You should have your pinvotes inside an span with a class for searching after the ajax is complete
$(".fa.fa-star").click(function(){
var _this=$(this)
$.ajax({
.....
success:function(msg){
_this.parent().parent().find('.votes-count').html(msg); //Accesing the parent then you should acces a span to your votes
}
})
})
Related
I'm making a Single Page Application with Ruby on Rails (it's my first ruby project ever so I'm definitely missing a lot of stuff yet).
So I have a side menu with some links and the right part of the page is supposed to hold a container which is meant to be filled with some content of partial pages.
The typical menu link I have now looks this way:
<%= link_to t('my-groups'), :controller => 'dashboard', :action => 'mygroups', :remote => true %>
I have a dashboard controller, here's the simplified version of it
class DashboardController < ApplicationController
def mygroups
respond_to do |format|
format.js
end
end
I have a dashboard template with the container div in it
<div class="right_col" role="main">
<h2>This is the default content of center page</h2>
</div>
And here's the routes.rb path for it:
get 'dashboard/mygroups' => 'dashboard#mygroups'
I also have one partial page alogside with my dashboard template and it's called _mygroups.html.erb and a javascript file mygroups.js.erb which is called as my controller action
look at the screenshot of the structure
The contents of this js.erb file are:
$('.right_col').html("<%= escape_javascript(render(:partial => 'mygroups')) %>");
It all works and the partial contents appear inside the container on link click just fine.
But there are still 2 problems I couldn't google the answer for
The questions part:
1) It works with Ajax call but if I simply put this http://localhost:3000/dashboard/mygroups to my browser's navigation line and hit enter, it will give me this error
ActionController::UnknownFormat in DashboardController#mygroups
ActionController::UnknownFormat
Extracted source (around line #70):
def mygroups
respond_to do |format|
format.js end end
How can I avoid this and just redirect to index in this case?
I understand that ajax uses POST, but I tried to use post instead of get in routes.rb for this action, and it didn't work at all
2) What if I have a lot of actions for different partial pages, do I have to create a new js.erb file for each action? Can't it be done in some simplier way with just one file?
3) Is it possible to not specify controller and action on this link explicitly?
<%= link_to t('my-groups'), :controller => 'dashboard', :action => 'mygroups', :remote => true %>
I mean since it's supposed to be a POST ajax request, how come I need to display the url like this http://localhost:3000/dashboard/mygroups to a user?
Add format.html in controller like:
class DashboardController < ApplicationController
def mygroups
if request.xhr?
respond_to do |format|
format.js
end
else
redirect_to root_url
end
end
you can add url in link_to tag like:
<%= link_to t('my-groups'), '/dashboard/mygroups', :remote => true %>
Answers to you questions
When you hit the URL in browser, it sends vanilla HTTP get request(non-ajax) which your controller action is not configured to handle it. You need to add format.html and template named groups.html.erb where generally you will list all the groups, I guess.
respond_to do |format|
format.html
format.js
end
Ideally you have to create separate file for each action but if you can take something common out of different action then you can move common template code to a partial and render it either in a separate template having something special or from the controller action directly.
Yes. The rails way is to use routes helper. Run rake routes to list all available routes in your app and find relevant helpers.
I would strongly suggest to read the rails guide to understand how everything works.
I have a working Ruby on Rails form that currently posts my results and redirects the user to another view and posts the results. The flow is:
views/tools/index.html.erb -> views/tools/ping.html.erb
Since I have it working now, I'd like to convert it to AJAX and keep the user on the views/tools/index.html.erb view, getting rid of the redirect to enhance the user experience. However, I'm unsure of how to proceed based on the way that my Tools controller is currently setup, and my incredibly lacking knowledge of AJAX.
So, here's what I currently have:
views/tools/index.html.erb (added 'remote: true' to form)
<h1> Tools </h1>
<h3> Ping </h3>
<%= form_tag ping_tool_path(1), method: "post", remote: true do %>
<%= text_field_tag :ip, params[:ip] %>
<%= submit_tag "Ping", name: nil %>
<% end %>
<!-- this is where I'd like to put the results via AJAX -->
<div id="output"></div>
controllers/tools_controller.rb
class ToolsController < ApplicationController
def index
end
def ping
ping_host(params[:ip])
save_host(params[:ip])
# Adds based on recommendations
respond_to do |format|
format.html { redirect_to tools_path }
format.js
end
end
protected
def ping_host(host)
f = IO.popen("ping -c 3 #{host}")
#output = f.readlines
tool_type = "ping"
tool = Tool.find_by(tool_type: tool_type)
tool.increment(:tool_hit_count, by = 1)
tool.save
#results = "<pre>#{#output.join}</pre>".html_safe
end
def save_host(host)
host = Host.find_or_create_by(host_ip: host)
host.increment(:host_hitcount, by = 1)
host.save
end
end
views/tools/ping.html.erb
<%= #results %>
views/tools/ping.js.erb (New file based on suggestion)
$("#output").html("<%= #results %>");
routes.rb
Rails.application.routes.draw do
root 'tools#index'
resources :tools do
member do
post 'ping'
end
end
end
This is what I see on the Network tab in Google Chrome after submitting the form:
So, what I know at this point is that I'll need to add remote: true to my form in views/tools/index.html.erb, and this is where I get lost.
It seems that I have an issue ATM with the fact that I've abstracted the form to use my ping method in the Tools controller, whereas all of the tutorials (and railscasts) I've gone through are doing AJAX on CRUD methods and a given model, not something like what I've build here so far. Please help me understand AJAX!
You're on the right track, now you need to modify the def ping action with a respond_to block.
def ping
ping_host(params[:ip])
save_host(params[:ip])
respond_to do |format|
format.html { redirect_to tools_path } ## if you still want to have html
format.js
end
end
and create a file called view/tools/ping.js.erb where you have javascript that will be run and returned asynchronously
$("#output").html("<%= j #results %>");
The <%= %> block will be evaluated first and replaced with the output of that ruby code. Then this will be inserted into the #output div.
I'm trying to understand AJAX requests in Rails. I have a form that I currently submit using remote: true. I want to respond with an HTML redirect if the request is successful, and run an error message with Javascript if it is unsuccessful. However, no matter what the outcome is, the request seems to expect a .html as the return.
respond_to do |format|
if conversation
format.html { redirect_to(conversation_path(conversation)) }
else
format.js
end
end
This is called after I save the conversation call on AJAX. On a successful save, the path HTML is correctly sent back, but is not rendered on the client. But on an unsuccessful save, it expects the .html and throws an error. How do I accept .js as a response? My goal is to just pop up an error if the call is unsuccessful and redirect_to on a successful call.
Edit: My form_for:
<%= form_for :conversation, url: :conversations, remote: true, html: { class: "conversation-form" } do |f| %>
Here's a suggested alternative to your end-goal - in the controller, drop the format.html entry in your respond_to block. Also, set conversation to an instance variable that the view template can access:
class YourController < ActionController::Base
def your_action
# awesome code doing stuff with a conversation object goes here
#conversation = conversation
respond_to do |format|
format.js # your_action.js.erb
end
end
end
Then, put the redirect logic in your javascript view template (for the above example: app/views/.../your_action.js.erb):
<% if #conversation.errors.any? # or whatever condition you want to show a popup for %>
// put your javascript popup code here
alert('Errors happened!');
<% else %>
// this is how you do a redirect using javascript:
window.location.href = "<%= conversation_path( #conversation ) %>";
<% end %>
Hope this helps!
I have a website that has a lot of AJAX forms and as it is now I have to make a new js.erb view for each one of them to just post a message that pretty much says completed but is unique to each action.
Is there a way that I can combine or forward one action to a message action in the controller so I would only need one view to handle all the JavaScript messages
Here is what I have:
Controller:
def some_action
{ do some things here }
respond_to do |format|
format.js
end
end
View:
some_action.js.erb
$('#messages').append("<%= escape_javascript(render :partial => 'flash_message') %>");
<% if #error == "True" %>
$('#flash').removeClass().addClass( "error" ).html('<%= escape_javascript(#message) %>');
<% else %>
$('#flash').removeClass().addClass( "success" ).html('<%= escape_javascript(#message) %>');
<% end %>
Would rather have one action in the controller to control all messages when no other changes are necessary.
You can abstract that functionality into instance methods, something like this
def ajax_success(message)
#message = message
render 'ajax/success'
end
def ajax_failure(message)
#message = message
render 'ajax/failure'
end
Then in your controller
def update
if (successful)
ajax_success
else
ajax_failure
end
end
You can either define these in your ApplicationController, or in a module that is included in any controllers where you wish to use them.
There are some issues here when you wish to have actions that respond to multiple content types, but for actions that should only respond to .js this should be fine.
Also, I think the standard practice for AJAX responses like this would be to return a JSON message, and then have some javascript function that could decode it and transform the page appropriately.
I'm working on a very simple RoR4 forum-like application. This is the forums_controller.rb actions for creating a new forum:
def create
#new_forum = Forum.new(forum_params)
if #new_forum.save
respond_to do |format|
format.html { redirect_to forums_path }
format.js
end
else
respond_to do |format|
format.html { render 'new' }
format.js { render partial: 'form_errors' }
end
end
end
Nothing magic there. The create js.erb looks like this:
<%= add_gritter("This is a notification just for you!") %>
<%= broadcast "/forums/new" do %>
$('#forum_form').remove();
$('#new_forum_link').show();
$('#forums_table').append('<%= j render #new_forum %>')
<% end %>
Everything is actually working fine. The broadcast block call you can see uses Faye to broadcast the javascript managing the changes in the interface.
My concern is, whatever is outside of the block in the js.erb file (i.e. that add_gritter call) is totally ignored. I'm sure it's not a gritter problem because changing that line for a simple alert('hi'); does nothing. However, if the call is moved inside the block it gets executed (with the annoying effect that every client gets the notification, alert or whatever). I am really out of ideas regarding this, and would appreciate any help.
<%= broadcast "/forums/new" do %>
is spitting the result of the execution as javascript (that HTTOK) which makes it go meh. So it should be
<% broadcast "/forums/new" do %>
Note the lack of the =.