how to render records in loop - ruby-on-rails

I am trying to render all the record of articles having true bookmarked. but it is showing this error :
Render and/or redirect were called multiple times in this action.
Please note that you may only call render OR redirect, and at most
once per action. Also note that neither redirect nor render terminate
execution of the action, so if you want to exit an action after
redirecting, you need to do something like "redirect_to(...) and
return".
Here is my code:
def index
# Also we are showing all showcased articles
if params[:bookmarked]=="true"
#favourite=Favourite.all
#favourite.map do |f|
article_id = f.item_id
#article = Article.find_by_id(article_id)
render :json => #article
end
end
end

Related

Ruby on Rails 6. Using Ajax after redirection

Say, I have users list on the '/users' page and 2 actions for the 'user' entity: 'index' (with using of Ajax) and 'destroy'.
def index
...
respond_to do |format|
format.html
format.js
end
end
def destroy
...
redirect_to users_url
end
I want to destroy a user (right from the '/users' page) and use Ajax of the 'index' action after that ('index.js.erb' file) in order to render only a part of the opened '/users' page.
Is it possible to do that?
My current solution right now is to use Ajax for 'destroy' action (a separate 'destroy.js.erb' file) and duplicate needed changes for 'index' page there. But, first of all, it's a code duplication, and second, in this case my pagination links are broken (I use 'Kaminari' gem and looks like it works fine only with 'get' requests, at least by default).
There is a 'view' part of updating with Ajax, if necessary:
<div id="users_table">
<table class="table table-hover table-borderless">
...
<tbody>
<%= render #users %>
</tbody>
</table>
<div><%= paginate #users, remote: true %></div>
</div>
If you want the destroy action to render the index.js.erb:
def destroy
...
respond_to do |format|
format.js { render action: :index}
format.html { redirect_to users_url}
end
end
But, to render index.js you will need to, in your destroy action, rebuild the #users object and ensure you're rebuilding it for the correct page. So, when you call the destroy action you'll need to pass the ID(s) of the user(s) you want to destroy, as well as the page you are on.
Your destroy.js.erb should (on successful destruction) remove the destroyed element from the index by deleting a part of the HTML. I don’t expect that the code to do that duplicates the code you have in the index view.
Post your current destroy.js.erb as well as the relevant part of index.html.erb for more help though.
You can also use redirect within a respond_to so your HTML call will redirect while the Ajax uses destroy.js.erb
respond_to do |format|
format.js
format.html { redirect_to users_url}
You could also hack your way to your answer by calling render :index for the js response. But, if you were to try to render the index view here you’ll definitely get duplication of code, along with an extra DB call and probably some broken pagination. So, I’d recommend that you take the approach I first suggested (use destroy.js.erb to remove that user from the HTML)
Finally, more generally, when you’re trying to avoid duplication of view code; a partial might be the answer

How to render erb template to string inside action?

I need a string of html (something like "<html><body>Hello World</body></html>") for faxing purpose.
I wrote it into a seprate erb file: views/orders/_fax.html.erb ,
and try to render the erb in action: html_data = render(:partial => 'fax').
Here is part of the controller that raises the issue:
respond_to do |format|
if #order.save
html_data = render(:partial => 'fax')
response = fax_machine.send_fax(html_data)
......
format.html { redirect_to #order, notice: 'Order was successfully created.' }
format.json { render json: #order, status: :created, location: #order }
else
format.html { render action: "new" }
format.json { render json: #order.errors, status: :unprocessable_entity }
end
end
It gave me an AbstractController::DoubleRenderError as below:
AbstractController::DoubleRenderError in OrdersController#create
Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and at most once per action. Also note that neither redirect nor render terminate execution of the action, so if you want to exit an action after redirecting, you need to do something like "redirect_to(...) and return".
How to solve this problem?
If you only need the rendered HTML, and don't need any functionality from the controller, you might try using ERB directly within a helper class, eg.:
module FaxHelper
def to_fax
html = File.open(path_to_template).read
template = ERB.new(html)
template.result
end
end
The ERB docs explain this in more detail.
EDIT
To get the instance variables from the controller, pass the binding into the result call, eg:
# controller
to_fax(binding)
# helper class
def to_fax(controller_binding)
html = File.open(path_to_template).read
template = ERB.new(html)
template.result(controller_binding)
end
Note: I've never done this, but it seems workable :)
Use the #render_to_string method
it works the same way as the typical render method but useful when you need to add some templated HTML to a json response
http://apidock.com/rails/ActionController/Base/render_to_string
If you don't want to escape html, just call .html_safe on it:
"<html><body>Hello World</body></html>".html_safe
Re your error, please post your OrdersController - looks like you are calling render or redirect more than once in the create action.
(Btw, just in case you are trying it - you can't render a partial in a controller - you can only render partials in views)
Edit: yeah your problem is you trying to render a partial in the controller action. You could use an after_create callback to set up and send the fax - though again you won't want to use a partial (as they are for views). http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html
Edit: for your fax problem,you could create a normal Ruby Class, see this excellent bit of advice from Yehuda: https://stackoverflow.com/a/1071510/468009
The reason is you cannot render or redirect inside the same action more than once at a given time.
But in your code, you have both render and redirect. I think in your controller you can use simply only the render, assuming you don't need any json output.
Try this
def create
#order.save
render(:partial => 'fax')
end
I haven't tested this, but I guess you get the idea :), and think about a way to handle errors as well (in case order didn't save).

Redirect to after successful ajax form

I've got a form with remote => true.
And right now my controller looks like:
# POST /items
# POST /items.json
def create
#item = #store.items.build(params[:item])
respond_to do |format|
if #item.save
format.html { redirect_to edit_admin_item_path(#item), :flash => {:success => "#{#item.name} was successfully created."} }
format.js { render :js => "window.location.href = ('#{edit_admin_item_path(#item)}');"}
format.json { render json: #item, status: :created, location: #item }
else
format.html { render action: "new" }
format.js { render :partial => 'fail_create.js.erb', :locals => { :ajax_errors => #item.errors.full_messages } }
format.json { render json: #item.errors, status: :unprocessable_entity }
end
end
end
Which works but feels very clumsy. It also doesn't allow me to use a flash notice, which is sad time indeed.
Ideally I feel like I should be able to simply use "format.js { redirect_to...} or check against the request headers and redirect_to. Sheesh!
I'm not sure what the best solution is. Any advice would be super awesome, thanks in advance!
-- PS -- I know this has been asked somewhat before but to no avail: How to redirect after a successful AJAX form submission. There seems to many questions similar floating around, but no real solutions.
I think it might be impossible. The response to a Ajax request is processed by XMLHttpRequest. If a 3xx response is returned, XMLHttpRequest will follow the redirect itself, if the URL is of same origin. No matter how you set the headers, the browser cannot be aware of that. So the only way could be changing window.location with some Javascript.
I use a combination of Rails responders to generate my response messages and some content in my <action>.js file.
The content of — say update.js would look something like this:
// Checks if the article slug has changed.
// If it has the entire page should be reloaded at that new location.
<%= reload_if_slug_changed #article, params[:id] %>
// Displays the flash notices
// See ApplicationHelper#js_flash_response
<%= js_flash_response %>
Where the different methods are defined in some helper (in my case my ApplicationHelper). The content of the different methods are as follows:
def js_flash_response
if flash.now[:notice].present?
js = "$('#notice').html('#{flash.now[:notice]}').change();"
elsif flash.now[:alert].present?
js = "$('#alert').html('#{flash.now[:alert]}').change();"
end
end
def reload_if_slug_changed object, expected_value
"window.location.href = '#{url_for [:edit, object]}';" if object.slug != expected_value
end
The content of the flash messages are generated automatically by Rails responders and displayed with the now scope that deletes the from the flash hash, ensuring that if the user reloads (after the flash has been displayed) they will not reappear.
I don't believe that you should ever make a form pointing to a restful create action a remote one, because you would always expect critical redirect, so in my case I only need to redirect if the url slug has changed.
I hope that this helps. It's not a solution, but simply the way that I handled some of the same problems.
Best regards.
Under your scenario, here's how I would inject javascript into the page from a controller action. After you've completed the logic section of your action insert something like this:
render :update do |page|
page << "javascript_here"
end
This should allow you to insert you window.location or create a javascript flash method and call it when your create method executes correctly.
If you're looking to DRY up your controller actions, I would recommend looking into this Railscast about make_resourceful. Make_resourceful automagically performs each core activity for each action. It also allows you to tap into the hooks that they've created such as before :create, after :create, response_for :create, and after :create_fails. By using this gem, you can run code based on the success or failure of your methods and have finer grained control over them.
In addition to this, you should be able to initialize a create.js.erb and create_fails.js.erb in your view file, include a format.js without anything passed to it in your controller, and Rails will automagically run that file that contains javascript depending on if the controller action executed successfully.

AbstractController::DoubleRenderError that shouldn't be

I've been getting the following error when I hit this destroy method in a my User controller.
AbstractController::DoubleRenderError (Render and/or redirect were called multiple times in this action.
Please note that you may only
call render OR redirect, and at most once per action. Also note that
neither redirect nor render terminate execution of the action, so if
you want to exit an action after redirecting, you need to do something
like "redirect_to(...) and return".):
It's a strange one, because I honestly am only responding once to the call.
Here's my action:
def destroy
user = User.find(params[:id])
if user.has_role_for? current_client
# then we remove the role
user.has_no_roles_for! current_client
# was that the users only role?
if user.roles.count == 0
user.destroy
end
respond_with head :ok
else
respond_with({:error=>'unauthorised'}, :status => :forbidden)
end
end
Any ideas?
Try adding " and return" after the respond_with lines:
respond_with head :ok and return
respond_with({:error=>'unauthorised'}, :status => :forbidden) and return
head(:ok) doesn't return something you can respond_with. head :ok renders a 200 with no body. respond_with renders via the responder some representation of the object you passed into it. head calls render, respond_with calls render, hence the double render error.
You should change that line to just head :ok.

render (and redirect_to) should somehow terminate the processing of an action?

def update
#user = User.find(params[:id])
if #user.update_attributes(params[:user])
render :action => show
end
render :template => "fix_user_errors"
end
The previous code will generate an error (because render is called twice) in the case where update_attributes succeeds.
The act of calling render (and redirect_to) should somehow terminate the processing of an action?But its not why?
render doesn't actually terminate the processing of the action.
You need to add an else to your if statement:
if #user.update_attributes(params[:user])
render :action => show
else
render :template => "fix_user_errors"
end
I think you can also use "return render ..." which will return immediately from the action method but this might have unintended consequences.
No, calling render does not end your action. render is a method to tell your controller which template is going to render if you do not want the default one, not to actually tell it you are done processing.
You might want to call return after you call render, if you are actually done.
Also, calling redirect (I am guessing this, I am not sure) actually sends a Location header to your browser, but does not end your action. You need to return or branch too after calling it, so you do not call it twice.
You can use the else, doesnt really has sense to render an action and render another. I would write like this:
def update
#user = User.find(params[:id])
if #user.update_attributes(params[:user])
redirect_to :action => show
else
render :template => "fix_user_errors" #probably you want to render the edit template here.
end
end

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