Rails js.erb response not sending locals to Haml partial - ruby-on-rails

I realize this is similar to some other questions, but I have been through a fair number of those and I think I'm doing what they suggested, but my code is still not working.
So, as the title says, I'm attempting to load a partial from a js.erb file (in response to an AJAX call.) However, it is not working correctly.
full_list.html.haml:
=link_to(test_path(#work), id: "privacy-button", remote: true) do
= render "privacy_button_content", locals: {:show_others => #work.show_others}
_privacy_button_content.html.haml:
-if locals[:show_others] == false
-test_string = "twas false"
-else
-test_string = "twas true"
%p = test_string
works_controller.rb:
def test_function
#work.model_function
respond_with(:layout => false)
end
test_function.js.erb:
$("#privacy-button").html("<%= escape_javascript render(:partial => 'privacy_button_content', locals: {:show_others => #work.show_others}) %>");
So the full_list has privacy_button, which is rendering the partial, and the response to clicking the #privacy-button should be to modify something in the controller, and get the response.js.erb.
This works correctly on page load (so passing the local to the partial does work,) but whenever I run the AJAX call I'm getting
(undefined local variable or method `locals' for #<#<Class:0x00000005006338>:0x000000068481f8>):
Any help would be appreciated.

Update _privacy_button_content.html.haml as below:
-if show_others == false
-test_string = "twas false"
-else
-test_string = "twas true"
%p = test_string
When you pass show_others in locals hash, a local variable would be created for you named show_others. You can access it as show_others in the partial and not locals[:show_others].
Refer to Passing local variables in Rails Guides.

Apply Kirti Thorat's change and then change
= render "privacy_button_content", locals: {:show_others => #work.show_others}
for
= render "privacy_button_content", show_others: #work.show_others
Also remember that views should not have logic, it should be in a helper or in a decorator
BTW: I think %p = test_string should be %p= test_string

So, I've figured it out. It seems that specific error I was getting had to do with the render syntax when working when haml (I got the same issue when I specified render :partial from the view, so it wasn't unique to the js.erb.)
The code in partial.js.erb now looks like:
$("#privacy-button").html("<%= escape_javascript render("privacy_button_content", :locals => {:show_others => #work.show_others}) %>");
As you can see, the main difference is having render "works_group_list" rather than render( partial: => "works_group_list". As I said, I believe this may be related to my views being written in Haml, though it should be noted that the render(partial:...) syntax does work when not attempting to pass local variables from a js.erb.
I was also getting some little issues because I kept referring to something as #my_element in the js when in the html it was #my-element. So if you're encountering this issue, checking your spelling (for the thirtieth time) never hurts.
Edit:
Just a note, as others have pointed out using the locals hash is not mandatory. So the line of code could instead be
$("#privacy-button").html("<%= escape_javascript render("privacy_button_content", :show_others => #work.show_others ) %>");
This will work as long as you update your partial appropriately (referring to var instead of locals[:var]).

Related

How to upgrade the :update=>'div_id' option of remote_form_for from Rails 2 to Rails 3?

I can't figure out how to upgrade this code from Rails 2 to Rails 3:
<% remote_form_for(item, :update => 'div_id') do |f| %>
...
I tried this:
<%= form_for :item, :remote => true, :url => { :controller => "items", :action => "create" }, :update => 'div_id' do |f| %>
...
It creates the new item but it fails in updating the content within <div id="div_id"></div> tags. It seems Rails 3 no longer supports the ":update" option for a remote form_for. Any suggestion?
You could use RJS, but that's being deprecated too (and for good reason). The simplified, best-practices way to handle this in Rails 3+ is as follows (assuming jQuery):
# your_view.html.erb
<div id="receiver-id"></div>
<%= form_for :some_model, :remote => true, :id => 'form-id' do |f| %>
...
<% end %>
# application.js (or any other .js loaded on the page)
$(function(){
$('#form-id').bind('ajax:success', function(xhr, data, status){
$('#receiver-id').html(data);
});
});
The ajax:success hook gets called by the jquery-ujs (aka jquery-rails, aka rails-ujs) remote link/form handler. See for yourself. There are lots of other callbacks/hooks available for you to use, too. If you wanted to make this even more flexible, you could use live instead of bind, and bind to a class that dictates where the ouput goes (e.g. "sidebar") and then all remote links/forms with the sidebar class would have their HTML response go to div#sidebar.
The most straightforward way to do this would be to write a javascript view template, e.g. create.js.erb which would look something like this:
$('#div_id').html("<%= escape_javascript(render(#item)) %>");
(depending on your setup, of course, I'm assuming an #item variable and an associated _item partial)
Edit:
coreyward is right. This is the RJS way which is more of the old fashioned Rails 2.x "Rails way". It's probably more familiar, but has issues. Your specific case is one of them, actually, as typically you might bind to an HTML element to update using the record's id (e.g. div #item_1), and in the create case there is no id available beforehand, complicating matters.
Binding via clientside JS eliminates this issue. RJS works in something of a vacuum, making assumptions about the state of the client's HTML and having no access to it.
I know the question is old but I when migrating to Rails 3 I found a pretty good way of doing this, so I thought I would post it here in case anyone else is in a similar solution.
In layouts/update_page.js.erb I put this file:
$j('#<%=#update_div_id||"list_div"%>').html('<%= escape_javascript render(:partial => (#partial_div||"index"), :locals => #local_hash) %>');
This is mainly used for searches that use remote, so in the index action in the controller, I just added the following code.
respond_to do |format|
format.html
format.js {render 'layouts/update_page'}
end
Since remote is being used, it will always try to use javascript first, so it will render the update_page.js.erb file from above. For us, we almost always use the div#list_div on our index pages, so we update that by the default, however if you need to update something different, you can pass in #update_div_id, and if you need to render a different page, you can pass in #partial_div.
To clarify, for a lot of things, it is probably better practice to use the callbacks, but I found this to be a much easier way, when we had to migrate over nearly 100 of these calls.

Rails 3, rendering a partial for the given controller if it exists?

In my application.html.erb layout for my app, I want to have a partial that renders if it exists for the given view. for example.
If the visitor is at http://example.com/users/show, I'd want the partial /users/_sidebar.html.erb to render.
But if the visitor were at say, http://example.com/user/locations/san_francisco, I'd want the partial /users/locations/_sidebar.html.erb to render.
So the thing here is that if there were no partial for that controller/action it would render some generic partial in my shared directory, and I'd rather not litter every single view with content_for blocks ya know?
Any ideas guys?
My solution is a bit different. Throw this in your application helper:
def render_partial_if_exists(base_name, options={})
file_name = ::Rails.root.to_s+"/app/views/layouts/_#{base_name}.html.erb"
partial_name = "layouts/#{base_name}"
else_file_name = ::Rails.root.to_s+"/app/views/layouts/_#{options[:else]}.html.erb"
else_partial_name = "layouts/#{options[:else]}"
if File.exists?(file_name)
render :partial => partial_name
elsif (options.key?(:else) and !options[:else].nil? and File.exists?(else_file_name))
render :partial => else_partial_name
end
end
Then in your view:
<%= render_partial_if_exists "page_#{controller.action_name}_sidebar", :else => "page_sidebar" %>
In an edit action, if "layouts/page_edit_sidebar" exists it renders it, otherwise it will render a standby "layouts/page_sidebar"
Sean Behan has a great post on exactly this:
http://seanbehan.com/programming/render-partial-if-file-exists/
I might move it to a helper and tweak it a bit to:
<%= render_sidebar %>
# This method could use either the rescue or the if file exists technique.
def render_sidebar
render(:partial => "/#{controller.name}/sidebar"
rescue
#default side bar
end

Partial not updated on first click

I am having problems with a remotely executed action and a partial that doesn't update the first time I click the link.
Inside the view (a partial named books) I am creating a link:
link_to "⊗", read_book_path(book), :remote => true
The read_book_path is defined in routes.rb
There is also a conditional that displays a different text when that book is read.
Inside my controller, I have defined a new action:
def read
#books = Book.all
#book = Book.find(params[:id])
#book.read = !#book.read
#book.save
respond_to do |format|
format.html { redirect_to(books_url) }
format.js {render :layout => false, :locals => { :book => #book } }
end
end
This means I need a file read.js.erb, this file's content is:
$("#books").empty().html("<%= escape_javascript( render(:partial => "books") ) %>");
When I click the link, I can see in the terminal window that the database field is updated but the partial is not. Clicking the same link again updates the partial.
Changing the link to :remote => false also works but the page reloads (as expected).
I have tried to debug it with Safari and the Developer tools and I can see the server's response when clicking the link for the first time.
Something is wrong there, the HTML generated by <%= escape_javascript( render(:partial => "books") ) %> contains the wrong HTML with the old content of the partial. Only the second or third click shows the updated HTML.
I have integrated jquery-ujs - is that the reason the partial doesn't update the first time or am I missing something else?
This really gave me a headache, can you help me?
Edit:
If that helps: I created a listener in application.js to ajax:before and ajax:complete. The first one shows a little spinner, the second one hides it.
When I click the link, the spinner shows but it doesn't hide.
It looks like you have an ordering problem that's causing the trouble. You're capturing a complete set of books into the #books variable and then modifying a separate copy of a single book. This change will not be propagated back.
# Load and modify the one book by flipping the flag
#book = Book.find(params[:id])
#book.read = !#book.read
#book.save
# Load all books
#books = Book.all
As a note this is an extremely inefficient way of doing things, so I hope you're not working on a large amount of data. You might find it's easier to do this by simply toggling the one field with a simple UPDATE query:
Book.update_all({ :read => true }, { :id => params[:id] })
I'm not sure why you're calling $(...).empty().html(...) instead of simply $(...).html(...) since the html() method should replace the HTML wholesale with no need to clear it in advance.
One thing that might help is using .js.rjs where the equivalent would be:
page[:books].replace_html(:partial => 'books')
With simple JavaScript, RJS allows you to eliminate a lot of the drudgery. You can use JS in RJS as well for cases where there is no equivalent:
page << '$("#books").empty()'
page[:books].replace_html(:partial => 'books')
To make this more Rails friendly, you could call your partial _book which would make the local variables redundant. Each partial has a default variable with a name matching the template name:
render(:partial => 'book', :collection => #books)

Rails 3: Simple AJAXy Page updates?

I can't believe I've been looking four hours for this simple task, but I have.
In Rails 2.3, I could replace one section of a page with this simple code:
render :update do |page|
page.replace_html "div_id", :partial => "new_content",...
end
In Rails 3, Ryan Bates has me writing entire new javascript functions, switching from Prototype (rails default) to jQuery, and otherwise not enjoying life. The other tutes are no more straightforward.
What am I missing? How do we replace a <div> these days?
Thanks, guys. The official answer seems to be that, yes, the team felt simple is the enemy of good and made it more complicated.
The first key is to create a .js.erb file NAMED for the method CALLING the ajax update. So if the index method handles the update, put the raw javascript in index.js.erb. This goes in the views folder.
Second, the code that worked in index.js.erb was
m = $('list_users');
m.innerHTML = "<%= escape_javascript(render :partial => "reload_users") %>";
Then to make the call, add in the respond_to block of the controller method, add:
format.js
Finally, the calling view has:
<%= link_to "Update User List", #reload_users_path, :remote => true %>
By the way, supposedly all the old pages using page.replace will work if you install a plugin. The plugin download page suggests that it broke in the last releases of Rails 3 and has not been fixed. Also, various bloggers will come to your home and birch-switch you if you use it.
The whole RJS stuff makes the javascript inline and makes the dom very obtrusive. Also, by avoiding inline javascript you could open up other possible ways of optimizing you javascript by compressing and caching those files in browser. Thats the reason why RJS is getting out of scope from rails 3. A little bit of getting around with jQuery or Prototype for a day should get you on gears with these kind of small stuff and will help the project on long run.
Do you still have jQuery in there? I'd recommend it over Prototype any day...
If it's still there you can just use the following in your Javascript:
$.get("<%= url_for path/to/partial %>",
function(response) {
$("#div_id").html(response);
});
This gets the partial via AJAX and just dumps it into the div with id div_id.
Hope this helps!
I'm not even sure you need to make an AJAX call to load that partial. I believe that in a js.erb file, a call to render(:partial => object_or_path) will just return a string with all the html, which you can wrap in a jQuery object and append. Example:
$('#div_id').html($('<%= render :partial => #object %>'))
As far as I know, along the same line as the answer above, you can do something like this in your template:
<%= link_to "Update User List", #reload_users_path, :remote => true %>
And in controller, do this:
respond_to do |format|
format.js {
render :text => "alert('reloaded')"
}
end
This way you can have controller "execute" client side JS much the same as as render :update used to do. This is equivalent to doing the following in Rails 2:
render :update do |page|
page << "alert('reloaded')"
end
Is there any reason why this approach is not advisable?
Try this:
page.call "$('#div_id').html", render(:partial => 'new_content')

creating dynamic helper methods in rails

I am trying to create a bunch of dynamic helper methods like these:
show_admin_sidebar
show_posts_sidebar
show_users_sidebar
So far I have this in my helper.rb file:
#spits out a partial
def show_sidebar(name, show_sidebar = true)
#content_for_sidebar = render :partial => "partials/#{name}"
#show_sidebar = show_sidebar
end
def show_sidebar?
#show_sidebar
end
In my application layout file I have this: (NB - I'm using HAML):
- if show_sidebar?
= yield(:sidebar)
This allows me to say the following in my views:
- show_sidebar(:foo)
- show_sidebar(:bar)
And this renders the desired partial.
The problem with this is that I can only add one sidebar per page. So, I figure I need to have dynamic methods like: show_admin_sidebar, show_foo_sidebar.
So I have tried to do this:
def show_#{name}_sidebar(show_sidebar = true)
#name = name
#content_for_#{#name}_sidebar = render :partial => "partials/#{#name}"
#show_sidebar = show_sidebar
end
and then in my layout:
- if show_sidebar?
= yield("{#name}_sidebar")
But rails does not like this at all.
I have tried almost everything I can think of in my helper file and nothing works.
The reason I am using helper methods for this is because I want my content div to be 100% page width unless there is a sidebar present in which case the main content goes into a smaller div and the sidebar content goes into it's own..
If I can't get this working, then I can easily fix the problem by just adding the partials manually but I'd like to get my head round this....
Anyone got any experience with this kind of thing?
The entire approach to this was bizarrely overcomplicated, didn't follow Rails conventions at all, nor make the slightest bit of sense, and shame on prior respondents for enabling this approach instead of helping him to simplify. My apologies for being 13 months late with the answer.
Your controller should be deciding if a sidebar is to be shown or not, and setting an instance variable #side_bar_name to either nil or a sidebar name string. Then somewhere in shared view code, probably views/layouts/application.html.erb, you would have something as simple as this:
<% if #side_bar_name %>
<%= render :partial => "partials/#{#side_bar_name}" %>
<% end %>
Or better yet:
<%= render(:partial => "partials/#{#side_bar_name}") if #side_bar_name %>
If you want to use a helper (which is not a bad idea for keeping your code DRY and readable) it would basically be the same code, just moved into the helper.
<%= side_bar_helper %>
def side_bar_helper
render(:partial => "partials/#{#side_bar_name}") if #side_bar_name
end
What the controller does is up to you. It would probably do something like this:
if session[:show_side_bar]
# maybe use cookies instead of session, or store user preference in a database
#side_bar_name = session[:side_bar_name]
end
Here is a solution for you, however I wouldn't suggest too much metaprogramming:
#Add the following snippet to the proper helper module:
['admin','user','whatever'].each do |name|
class_eval{
"def show_#{name}_sidebar(show_sidebar = true)
#name = #{name}
#content_for_#{#name}_sidebar = render :partial => 'partials/#{#name}'
#show_sidebar = show_sidebar
end"
}
end
def show_#{name}_sidebar(show_sidebar = true)
That doesn't look like valid Ruby to me. Are you parsing and evaling this yourself or just throwing that right in the file and expecting it to work?

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