I'm quite new to ruby and I'm trying to put the form to add a new post to the "application.html.erb" page.
Somehow I can't get it to work by just copying the code from the "app/views/things/_form.html.erb" page, and also I can't seem to get it to work by copying the code from the "app/views/things/new.html.erb" page.
If I do that I get the error:
First argument in form cannot contain nil or be empty
The error points towards:
<%= form_for(#thing) do |f| %>
This is a code that I find in the "app/views/things/_form.html.erb" page.
Can anybody point me in the right direction? To be honest, I don't even know where to start looking for the answer.
I think you should take a look at ruby on rails MVC model first, and also go through a basic tutorial. Just a quick review of you question:
application.html.erb is usually in the layout folder of rails,
it's job is to provide a root template/layout for the whole project if not specified.
usually you don't want to put any code that is not commonly
needed by all pages.
the reason it is giving you the error First argument in form cannot contain nil or be empty is because, the helper method form_for is expecting the controller to provide a #thing to the view file application.html.erb, in your case, it is obvious that #thing is not exist in your controller or your ApplicationController.
The #thing should be initialized in your controller. I suppose you've got a things_controller.rb that has a new action in it. In this action, controller should initialize #thing and therefore it is visible in app/views/things/new.html.erb.
You really shouldn't put forms in application.html.erb, but just to make the error disappear, you could do
<%= form_for(Thing.new) do |f| %>
(assuming you've got a Thing model in app/models/thing.rb).
This way you'll initialize an instance of Thing right in your application.html.erb view.
Related
I have stored html code in a database field which is passed to the rails app.
<%= raw #exercise.explanation %>
The normal text is rendered correctly, it´s in the <p> .. </p>; but inside there the image codes are just displayed so output on the page is:
This is correct rendered text.
<%= image_tag ("exercises/picture.png"), style: 'height:auto; width:50%;' %>
Further text.
When I use <img src="exercises/picture.png"> or <img src="picture.png">inside the database entry, no picture is loaded either, just the broken image symbol of the browser.
Do you have the Assets Pipeline on? If you do, this could happen because of the generated hash that it put on your static assets to avoid cache problems. The thing is that the image_tag helper resolves this. It's a trade-off, but you could disable the Assets Pipeline and see if it works. To keep it on and do this, you will need a more elaborated solution.
You can try if it is that by disabling the assets digesting:
config.assets.digest = false
Alternatively you can have ERB interpret #exercise.explanation
<%= ERB.new(#exercise.explanation).result(binding) %>
This will take your #exercise.explanation and process it through ERB which appears to be what you are hoping for.
Caveat:
Be very careful what you allow to be stored in these "template" fields as things can go bad if you do not/can not sanitize this input. ERB#result is essentially a call to eval (which can be very dangerous)
Is it possible to render another file, such as my show.html.erb, within my main.html.erb file?
"show.html.erb" belongs to a calendar controller. "main.html.erb" belongs to a Pages controller.
I want to do this because:
I need to access some specific data from within the calendar in the database.
I don't want my calendar to take up an entire view frame. I want it to be small and be integrated into the main page.
How would I go about doing this? Is it a silly idea?
Yes, with partials. So if you want to render _my_view.html.erb within some other view, you should insert the following:
<%= render partial: "my_view", locals: { myvar: #val } %>
Where you can pass variables to the partial through the locals hash.
In my rails app, I have a link to the root that renders in all browsers as
<html>
<head>
<style type="text/css"></style>
</head>
<body>19</body>
</html>
Server-side I can see all assets getting passed back. For some reason the browser will not display them because if I view page source I can see ALL my markup correctly.
Now if I load or reload the page localhost:3000 normally the page and all assets are displayed correctly. If I simply refresh I get nothing.
The only time this occurs is when I click a link back to the homepage like a href="/".
The behavior does not occur if I hardcode a href="localhost:3000/" but I don't want to do this.
Rails app, Turbolinks, nowhere in code do I use the number 19, rake routes with root GET well-defined, no public/index.html. I suspect something to the degree of caching or turbolinks but I have no clue how to resolve.
Edit: Config/Routes.rb
SCRR::Application.routes.draw do
root 'home#index'
#pages
get 'about' => 'pages#about'
get 'history' => 'pages#history'
get 'links' => 'pages#links'
get 'safety' => 'pages#safety'
get 'membership' => 'pages#membership'
get 'events' => 'events#index'
get 'grand_prix' => 'grand_prix#index'
get 'newsletters' => 'newsletters#index'
end
Edit 2: Chrome Devtools Console Errors
This error is probably more relevant
Resource interpreted as Font but transferred with MIME type application/x-woff: "https://netdna.bootstrapcdn.com/font-awesome/2.0/font//fontawesome-webfont.woff".
jquery-2.1.0.js?body=1:1078
25115 : CS -> BG : FAILED closepopuptoplevel
onloadwff.js:77
From what you've posted, I don't know whether this would be a Rails issue or a browser issue.
I see you've tagged turbolinks, which could be a contributor to the issue; so let's have a look as to what the problem might be for you:
ERB
The ERB code you should use should be the following:
<%= link_to "Home", root_path %>
If you're trying to reference the "home" url directly, there may be an issue with how you're rendering the URL, hence why it won't show. You should ensure you use the path helper as described above.
This should be coupled with the correct routes:
#config/routes.rb
root "home#index"
resources :pages, path: "" do
collection do
get :about
get :history
get :links
get :safety
get :membership
get :events
get :grand_prix
get :newsletters
end
end
Assets
You mention the assets don't render when you refresh the page, this could be an issue with Turbolinks, although I'm not sure
Turbolinks basically just reloads the <body> of the page, leaving the <head> intact. Although this might sound like nothing to do with your issue, perhaps the problem is to do with the way in which Turbolinks is working with your assets
From your edit, it may appear that your assets are not loading correctly, or are at least not being shown correctly.
I hope this helps, I doubt it will give you a constructive answer
So I have my main page, landingpage.html.erb, and I want to put a link on there that will lead to another simple page with a few more links to outside sources.
landingpage.html.erb
<%= link_to "press", '/press', :method => :get %>
press.html.erb
<h1>Test!</h1>
(I also made a partial, to test if that would get displayed. Its the same is press.html.erb but _press.html.erb)
Controller
def press
end
Error I keep getting:
Routing Error
No route matches [GET] "/press"
Where am I going wrong? Thanks.
You need to add the route to your config/routes.rb too. It depends on how you defined your other routes but a basic definition look like this:
get '/press', to: 'controller_name#press'
Read more about Routing in the Rails Guides.
I have a little problem with an output in ruby and rails.
I am still a beginner at rails, so it can be that the solution is pretty easy and i just can't see it.
I am trying to parse a website and put out some of the sourcecode on my own website.
Problem: it always puts out the whole source code as a text and is not interpreting the html code. how can i change that?
code:
page = Nokogiri::HTML(open("https://www.google.ch/search?client=ubuntu&channel=fs&q=google&ie=utf-8&oe=utf-8&redir_esc=&ei=WMpyUfSWEuz07AaTioCwDw"))
source = page.css('div#_css0')
<%= page %>
result:
http://postimg.org/image/dsaib9lx3/
I want to it to look like:
http://postimg.org/image/z9qlhoef5/
Thanks for any suggestions!
You should use raw in erb. It is actually equivalent to calling html_safe on it, but, just like h, is declared on a helper, so it can only be used on controllers and views.
page = Nokogiri::HTML(open("https://www.google.ch"))
<%= raw page %>
or
<%= raw Nokogiri::HTML(open("http://www.google.com")) %>
In Rails views every string content gets escaped, unless you use html_safe (docs)