Lately i have run into a few applications that are using js.erb and i am not really sure how to use it ...here is the code below. Can someone help me understand how this works?
in the routes.rb file
map.resources :player_emails
my controller player_emails_controller.rb in the create action
def create
#player_email = PlayerEmail.create(params[:player_email])
if #player_email.save
#response_txt = "The player has been emailed."
PlayerEmailsMailer.deliver_pattern_email(#something, #player_email, request.host_with_port)
#error = false
else
#error = true
#response_txt = "Please make sure you entered your name and a valid email address."
end
end
then i have the file player_emails/create.js.erb
$('#player_email_ind').hide();
$('#player_email_submit').show();
$('#player_response_msg').html("<%= escape_javascript #response_txt %>").fadeIn();
<% unless #error %>
$('#player_email_form')[0].reset();
<% end %>
i know what the jquery is going but i dont know how this is doing the ajax call. Does it just automatically do an ajax call when there is a js.erb...can someone explain the way this works and why i dont need a respond_to in the controller action telling it this is format.js
If a js (ajax) request is made it will respond by rendering the js.erb file and viceversa.
This is the default behaviour that is being performed:
respond_to do |format|
format.js{
render :template => 'create.js.erb'
}
format.html{
render :template => 'create.html.erb'
}
end
When the form is submitted, it does a POST to /player_emails. The resource declaration in routes.rb ensures the request is handled by PlayerEmailsController#create.
The controller is responsible for handling each format it receives. In the case of an AJAX call, the format is 'js', and is set by explicitly adding the format string to the end of the URL (/player_emails.js) or (more likely) by deducing the format from the request header.
In your case, the create action does not expect anything other than AJAX, so it takes a shortcut and omits the respond_to and format blocks. The controller has already figured out that the format is 'js', so when create is complete it takes the default action of rendering the appropriate template for the format (create.js.erb).
Does your form submit button have a :remote => true on it? If so, there might be some JavaScript in rails.js or application.js that automatically submits via AJAX. Bottom line is, there has to be some JavaScript somewhere that is making an AJAX call and asking for a js or JSON response, otherwise it would be an html request.
As for why you don't need a respond_to block, I'm not entirely sure. Maybe since the call is always being made by AJAX and there is a js.erb template available, it just does its thing without complaining. Is there an html.erb template at all? If not, try doing a regular form submit and see if it complains.
Related
I have a model called Question, and it has action create;
My goal is to display a flash message instantly, using a helper method (show_alert for example) when the instance is not valid.
question_controller.rb
def create
question = Question.new(question_params)
if question.save then
redirect_to show_question_path(question.id)
else
show_alert(:warning, question.errors)
end
end
application_controller.rb
helper_method :show_alert
def show_alert(type, message)
#type = type; #msg = message
respond_to do |format|
format.js { render :template => 'alert.js.erb'}
end
end
alert.js.erb
var div = $('<div></div>').addClass(`alert alert-${#type}`)
$('<ul></ul>').append( $('<li></li>').html(#msg)
div.append(ul)
$('#alerts').html(div)
But instead of displaying the flash, I get only the partial's code on the white screen.
see the screenshot
Since I've used respond_to I got another error: ActionController::UnknownFormat
I need the snippet of code in alert.js.erb to be executed, in order to render the flash, I think the trick is somewhere in the render function, but two hours of googling were just a waste of time.
Please help! Thank you in advance
ActionController::UnknownFormat error is showing up because the browser is sending HTML request to Rails server, but the respond_to block has only specified what to do in case of a javascript request from web server.
You will need to add a little bit of Ajax to achieve what you want. See this tutorial on Ajax. https://www.tutorialspoint.com/ruby-on-rails/rails-and-ajax.htm
Ajax will send a js request to browser in the background (i.e the browser will not refresh or show any signs of loading). This js request will be sent to Rails server and it will return the .js.erb file containing the script back to the browser. Now since this script was returned as a response to Ajax request by browser, the browser will already know that it is javascript that needs to be executed.
If you do not wish to implement Ajax, you have the alternate of doing something like this in your create controller:-
def create
question = Question.new(question_params)
if question.save then
redirect_to show_question_path(question.id)
else
redirect_to new_question_path(error: question.errors) #new_question_path is the action that displays the question form to the user
end
end
and then you can initialize an error variable in the action that displays the question form. e.g.
def new
#error=params[:error]
#rest of the code...
end
And then in somewhere in your new.html.erb (or whatever the html.erb file name is)
<script>
<% if #error %>
var div = $('<div></div>').addClass(`alert alert-<%= #type %>`)
$('<ul></ul>').append( $('<li></li>').html(<%= #msg %>)
div.append(ul)
$('#alerts').html(div)
<% end %>
// you might need to tweak the variable names in controller or the above code
</script>
(This code above may not be perfect. its just to give u an idea)
However this approach will not be as quick and beautiful as ajax because when the user will submit their question, the entire page will load again to display the error warning.
By default, all output from helpers is escaped. To show the HTMl as-is, you need to use the html_safe method (https://apidock.com/rails/v4.2.1/String/html_safe). See Using helpers in a view escapes the html?
I cannot be sure this without seeing your alert.js.erb but it could be that you need to use escape_javascript in your alert.js.erb
Something like (and I haven't tested this out) in your alert.js.erb
$('<%= escape_javascript("#{type} - #{msg}") %>').appendTo("#alert")
You can read more about it on Rails Guides - Working With Javascript in Rails
Hope this helps!
I have a pretty standard Rails HAML new object form that does the usual stuff and ends with:
= f.submit "Add scenario"
This works perfectly, and the scenarios_controller.rb is also a straightforward:
def create
...create scenario...
redirect_to scenarios_path
end
However, I have also developed a wizard-type form that needs to do some JavaScript on pressing my button:
= f.submit "Add scenario", :onclick => "return validateForm()"
In my CoffeeScript, I collect up all the information and finish up with:
$.post(
url
data
(data, textStatus, jqXHR) ->
# How do I follow the redirect?
return false
My url and data are correct as the above controller works correctly and creates my object, but my page doesn't redirect to scenarios_path. I think I should be doing something with the post result, but searching around the web I cannot find out what, and examining the returned fields in Chrome's debugger doesn't suggest anything. The only suggestion I saw was to use data.redirect, but such a field doesn't exist, although jqXHR.responseText seems to contain the page I want to redirect to.
I'd treat the HTML call to Scenario#create and the JS call to Scenario#create differently, using a respond_to block.
In your scenarios_controller.rb file:
def create
# create your object
respond_to do |format|
format.html do
redirect_to scenarios_path
end
format.js
end
end
In views/layouts/scenarios/create.js.erb, then put something like:
window.location.replace("<%= scenarios_path %>");
When you call Scenario#create with JS, the create.js.erb file gets rendered and forces the redirect. When you call Scenario#create with HTML, the redirect_to call happens as usual.
There is a similar question here and here but neither has the answer I'm looking for. I've also done a lot of searching for "rails format.js render" without being able to solve this.
In Rails 4, I have a validated form as follows:
<%= form_for(#message, :remote => true) do |form| %>
// don't want to call the js on submit here because
// I don't want it to execute if the form did not validate
I'm calling the js in the controller:
def create
#message = Message.new(params[:message])
if #message.valid?
NotificationsMailer.new_message(#message).deliver
respond_to do |format|
format.js { render "submit" }
end
else
render :new
end
end
I have "submit.js.erb" in the "messages" folder:
alert('js was called!');
When I submit the form, Terminal verifies the file DOES render:
Rendered messages/submit.js.erb (0.5ms)
...but on the screen, nothing happens. No alert, and no executed javascript. I've also tried creating "submit.html.erb" and wrapping my javscript in a script tag, and the same thing happens - the file loads, but the script does not execute.
Why? What do I need to do to tell Rails to execute the js?
Edit: After visiting Kelvo's resources and trying many things, the answer seemed to be adding this to the application.js...
$.ajaxSetup({
'beforeSend': function (xhr) {xhr.setRequestHeader('Content-Type', 'application/javascript');}
});
It also turned out that a manual line break and indentation (since it was not wrapping in my IDE) in my actual "submit.js.erb" was causing it to fail to execute, so there were really two problems.
This may be due to the fact that the returned content is not being evaluated. The browser does receive the file but does not know what to do with it, you have to include some JavaScript to handle the response as explained here :
You probably don't want to just sit there with a filled out <form>, though. You probably want to do something upon a successful submission. To do that, bind to the ajax:success event. On failure, use ajax:error. Check it out:
in your case you might try out
$(document).ready(function(){
$("#new_message").on("ajax:success", function (e, data, status, xhr){
eval(xhr.responseText);
});
});
in order to evaluate the js code.
you can read more on events fired during "data-remote" requests here
EDIT : forgot to mention, this script has to be included on the HTML file containing the form. Maybe just add it under your form.
This may be due to, returned content also including your default layout.
Try this:
format.js {render layout: 'no_layout', action: 'submit'}
Hope this helps...
Check this out. I've got a fairly simple form that's created with the following syntax:
<%= form_for([#issue, #issue_order], :remote => true) do |f| %>
The form, due to logic on the page, is actually called via javascript, like this:
$('#new_issue_order')[0].submit()
The controller handles the ajax request by doing a bit of logic then throwing out a little something like this:
respond_to do |format|
format.js
end
The AJAX that handles this response is in the following javascript:
$('#new_issue_order').on('ajax:success', issueOrder.processOrder)
..........
processOrder: function(e, data, status, xhr) {
$('.sign-up-errors').empty();
errors = xhr.getResponseHeader('X-Flash-Error').split(',');
for (i=0; i < errors.length; i++) {
$('.errors').append($('<p>' + errors[i] + '</p>'));
}
setTimeout(function() {
$('.errors').empty();
}, 3500);·
}
I figured that would allow it to respond to the remote request, but what I get instead is the following error:
ActionController::UnknownFormat
I tried creating a new.js.erb in my views (to correspond with the new page that it was on), but I'm still getting the same error. I haven't tried migrating my success handler AJAX to the new.js.erb code, because I'd prefer to keep my javascript handling in the javascript file in my assets for business reasons.
How can I get a seamless AJAX response? I've done it before, but respond_to has always confused me.
Setting the js response template as new.js.erb is incorrect.
The form itself is within new.html.erb template, guessed by convention. So, the form's action is supposed to point to #create.
In order to response correctly to this form's submission, you need to create a js template as create.js.erb, and respond to js in #create action.
Besides, in most cases you don't need to manually set Ajax response in assets js like
$('#new_issue_order').on('ajax:success', issueOrder.processOrder)...
Instead, you can just do it within create.js.erb. For example
$('#new_issue_order').css('background', 'green')
This script will be run after ajax:success event.
I am building a form in rails that will edit an existing question via ajax.
After the form is submitted and the question has been updated, the update method in the controller renders update.js.erb, which will hide the form again.
My problem is that the javascript code in update.js.erb is not executing at all.
I know that the file is rendering because it shows up in the server output, and when I put a
<% raise params %>
into it, it works.
However, even the simplest
alert('hello');
has no effect in the same file.
I've ruled out javascript and jquery configuration issues because the same code works perfectly in my edit.js.erb file. It's just not working in update.js.erb.
What am I missing?
Edit:
Firebug shows no errors. Here is the response in firebug's network panel:
alert('hello');
$('#question_body').replaceWith('<h4><p>jhsdfjhdsb k jdfs j fjfhds <strong>jfshaflksd;hf sdldfs l fdsalkhdfskhdfs</strong>;fd lfdksh hfdjaadfhsjladfhsjadfs ;df sjldfsj dfas hafdsj fdas ;ldfas ldfs df dl;hdf fdh ;fdj ;lfads</p></h4>');
def update
Edit 2:
This is the controller action:
def update
respond_to do |format|
if #question.update_attributes(params[:question])
format.html { redirect_to #question, :flash => { :success => 'Question was successfully updated.' } }
format.json { head :no_content }
format.js {}
else
format.html { render action: "edit" }
format.json { render json: #question.errors, status: :unprocessable_entity }
end
end
end
In your $.ajax call make sure to set the dataType option to "script" otherwise the response could be interpreted in other ways and thus not executed as JS.
Do you work with haml, or html.erb? If the former, then this might be the solution:
respond_to do |format|
...
format.js {render layout: false}
end
I had the exact same problem, found this question early on, took another hour or so of Googling to find this question on StackOverflow that led me to it: jQuery + Ajax + Haml. js.erb files not firing
In your update.js.erb file you need to escape javascript wherever you execute ruby code.
$('.container').empty().append('<%=
escape_javascript(
render 'update'
)
%>')
This is what solved it for me ...
This issue isn't just because of Controller side. It is also can be in the View side which is you didn't clarify the data-type of your post request.
Make sure in your console that the request is treated as JS.
Reference: Similar issue
I ran into the same issue and found this page. I tried methods listed here but found no luck. While later the following method solve my issue.
My originally code was:
$('#html_id').html('<%=#ruby_variable%>');
And I updated it to:
$('#html_id').html('<%=raw #ruby_variable.to_json%>');
Now it works as expected.
Found out what it is! 😊 (solution for rails 4)
If you have in your ajax call parameters that are not in your permitted list, the record gets saved, you get no error messages about the 'not permitted' parameters, but the update.js.erb won't run - even though your terminal will feed back 'Rendered update.js.erb etc'
If the extra parameter is an attribute in your model, just permit it.
The simplest way to permit non model parameter is to add in your model:
attr_accessor :paramKeyTroublesome
Then you can also permit it in the controller.
in the $ajax call, data needs to be hashed up properly:
data: {model_name: {paramKey1: value, paramKeyTroublesome: value}}
One more problem to be aware of is an error in your update.js file. Nothing will execute if there are any syntax errors. You can check this by going to your browser inspector and enabling Log XMLHttpRequests Then reviewing the output js file.