I have a search box that I only want to render on particular pages through the navigation section in my application.html.erb file.
How do I set exceptions? Is this done through the main application controller?
There are several ways to do this.
Most obvious way is to use an instance variable for flagging.
In your application.html.erb
<%= render 'search' if #search_box %>
And wherever you want to show the search, set the flag instance variable to true.
def show
#search_box = true
...
end
Edit
You might also want to utilize Rails' filters in your controllers if you want multiple actions to show search.
before_action :flag_search_box, :only => [:show, :new, :all_kinds_of_controller_actions_where_i_wanna_show_search]
...
private
def flag_search_box
#search_box = true
end
I might suggest to put the search box not in the application.html page but maybe in the separate html pages that you want it to render on. You could make the search a partial so that you could access it from the other pages with just one line of code.
Related
I have a method in my posts_controller to display most viewed posts.
def top
#posts = Post.all.order("post.views DESC").page(params[:page]).per(10)
end
In routes I have
resources :posts do
collection do
get :top
end
end
The problem is: when i go to /posts/top i have an error: Missing template posts/top, application/top Do I need to write view files for my every method (top isn't the only one) or I can somehow display them in my index file without duplication of code?
Just render the index template at the end of your method:
def top
#posts = Post.all.order("post.views DESC").page(params[:page]).per(10)
render :index
end
I would suggest you to have a close look to rails layouts and rendering documentation. You will get your answer as well concept behind them. Below is the snippet of doc.
In most cases, the ActionController::Base#render method does the heavy lifting of rendering your application's content for use by a browser. There are a variety of ways to customize the behavior of render. You can render the default view for a Rails template, or a specific template, or a file, or inline code, or nothing at all. You can render text, JSON, or XML. You can specify the content type or HTTP status of the rendered response as well.
So, I have search form, and search is avaliable obviously from any page.
I thought that it makes sense, that such action from application controller is placed in layouts/views folder.
But I just don't get- Rails doesn't see it. So I can't do this? How then should I provide action, avaliable from any page?
Code:
def tests_search
#tests=Test.test_search(params[:query])
respond_to do |format|
format.html
end
end
Route:
search_tests GET /search_tests(.:format) application#tests_search
Form:
<%= form_tag search_tests_path, {:id=>'test_search',:method => :get} do%>
Error:
Unknown action
The action 'tests_search' could not be found for ApplicationControllerr
You should create a new search controller. Use rails g controller search index which will create a search controller with a index action (you could also call the action something like result). Then add a search/_form.html.erb file in your search view folder, with the form:
<%= form_tag search_path, {:id=>'test_search',:method => :get} do |f| %>
and render this in your layout/application.html.erb where you want it to be:
<%= render "search/form" %>
This way you have a search form on any pages, that uses the SearchController to handle the search requests.
I would recommend using other controller to do this. It can be for example SearchController even if there will be only one method.
Notice that ApplicationController is controller that every other controller in application inherits from by default. So if it wouldn't be the case, it could make sense, but now every controller will inherit your test_search action, which is not desired.
If your search form will be a partial, then there is no difference whether this is in ApplicationController or in any other controller. You just have to point to right route.
Initially you have to explain yourself the flow. What you need is some partial which is rendered on all pages, and if a user adds some input to it and submits, he gets some output. Right? Good. So you start by creating a new partial somewhere in
app/views/shared/_search.html.erb
Then, you create your route in routes.rb to point to a controller's action. You don't have to place this in application_controller. Instead, create your search_controller.rb and create some action which responds to the form submission there.
Whenever you want to render your search form on other pages, you simply call render partial (more on that here) with something like
<%= render "shared/search" %>
This is good if you created the file above. Make sure your action exists and the name is correct, in your case it should be:
def test_search
...
end
Good luck.
I have a very simple site setup using awesome_nested_set and a single table called Pages.
I would like the ability to select different layouts in the admin when creating and updating Pages. What I envisioned is a drop down on the Pages form that allowed me to select a layout/template.
The only thing I know about layouts is you are required to add them to /views/layouts/ and specify the layout at the top of the controller. I need a way to manage layouts on a per Page basis inside the app itself.
Is that even possible? If so, can you explain on a high level how that might be done so I can have a starting point?
edit
Something like this:
You can easily change the layout at render by supplying the :layout key like so:
def some_action
#... stuff
render "some_action", :layout => "custom_layout"
end
You can also set layout to a symbol in the controller definition, and the controller will run the associated method to decide what layout to choose
class UsersController < ApplicationController
layout :decide_layout
private
def decide_layout
some_boolean ? "layout1" : "layout2"
end
end
You can also replace the symbol with a proc if you don't want the method located away from the usage. Finally, you can also call #layout in an action itself.
Assuming you have files in views/layouts called something like one_column.html.erb, two_column.html.erb, etc., and an attribute called layout on you page model, you could just do:
def show
#page = Page.find(params[:id])
render :action => "show", :layout => #page.layout
end
Is that what you're looking for?
I'm pretty new to Rails and have an issue which I can't quite get my
head around as to the architecturally 'correct' way of doing it.
Problem relates to what I kinda call sub-controllers. The scenario is
this:
I have a series of pages, on which is a panel of some form containing
some information (think the user panel on gitHub top right).
So, in my app, I have controllers that generate the data for the pages
and render out the responses which is fine, but when it comes to this
panel, it seems to me that you would want some sort of controller action
dedicated to generating this panel and it's view.
Question is, how do you go about doing this? How do I render a 'sub
controller' from within a view?
I would put the logic in a helper or a module. (http://api.rubyonrails.org/classes/ActionController/Helpers/ClassMethods.html)
Then render partials where you want these things displayed. (http://api.rubyonrails.org/classes/ActionView/Partials.html)
Like Herman said, if it's logic that you need generated after the controller hands off to the view (ie, the Pages controller generates a page view, but you want a customized panel) then put it in a helper. Or, call a separate method in your Pages controller before handing off to the view. Or, if it's a lot of logic, create a Module and stick it in your /lib folder. So you could have a whole Panel module with methods that generate different parts of your Panel and which are called by your controller. But if you want to call these methods from within the view, then you should use a helper instead.
I dont think a module is what is required here, modules are required for shared behaviour across a small subset of your classes.
What I think is required here is the understanding of the inheritance of ApplicationController and also layouts
so, for example, my layout might look like:
<html>
<head><title>Foo</title></head>
<body>
<%= render :partial => (current_user ? "/shared/user_widget_bar" : "/shared/login_bar") %>
<%= yield %>
</body>
</html>
Any code that i want to use for it would go in my ApplicationController since it would be shared across the majority of my app:
before_filter :generate_user_widget
def generate_user_widget
if current_user
#avatar = ...
#unread_messages = ...
end
end
I understand that it might be cleaner for it to belong in a separate controller BUT honestly, unless the code is huge, it doesn't matter and can even still be put inside a module which is then included by ActionController. However it does need to be inside ApplicationController if you consider the scope of it.
If there are more related pages, say for example, you have a Rails app that manages multiple sites and you want shared behaviour across a particular site, try creating a parent controller which has no actions and only private methods, any controllers that need to have access to those methods can inherit off it. That way you can apply before filters to all controllers which inherit off it, saving you the pain of forgetting to add one in your non-parent controllers.
e.g:
class SiteA::SiteAParentController < ApplicationController
before_filter :generate_user_widget
...
end
class SiteA::ProductController < SiteA::SiteAParentController
def index
...
end
end
well, if you really need to call a controller action from the view, you can use components. They were part of the framework, now they only exist as plugins. One such plugin that seems to be well maintained is here: http://github.com/cainlevy/components/tree/master
from its docs:
== Usage
Note that these examples are very simplistic and would be better implemented using Rails partials.
=== Generator
Running script/generator users details will create a UsersComponent with a "details" view. You might then flesh out
the templates like this:
class UsersComponent < Components::Base
def details(user_or_id)
#user = user_or_id.is_a?(User) ? user_or_id : User.find(user_or_id)
render
end
end
=== From ActionController
class UsersController < ApplicationController
def show
return :text => component("users/detail", params[:id])
end
end
=== From ActionView
<%= component "users/detail", #user %>
I have a Ruby/Rails app that has two or three main "sections". When a user visits that section, I wish to display some sub-navigation. All three sections use the same layout, so I can't "hard code" the navigation into the layout.
I can think of a few different methods to do this. I guess in order to help people vote I'll put them as answers.
Any other ideas? Or what do you vote for?
You can easily do this using partials, assuming each section has it's own controller.
Let's say you have three sections called Posts, Users and Admin, each with it's own controller: PostsController, UsersController and AdminController.
In each corresponding views directory, you declare a _subnav.html.erb partial:
/app/views/users/_subnav.html.erb
/app/views/posts/_subnav.html.erb
/app/views/admin/_subnav.html.erb
In each of these subnav partials you declare the options specific to that section, so /users/_subnav.html.erb might contain:
<ul id="subnav">
<li><%= link_to 'All Users', users_path %></li>
<li><%= link_to 'New User', new_user_path %></li>
</ul>
Whilst /posts/_subnav.html.erb might contain:
<ul id="subnav">
<li><%= link_to 'All Posts', posts_path %></li>
<li><%= link_to 'New Post', new_post_path %></li>
</ul>
Finally, once you've done this, you just need to include the subnav partial in the layout:
<div id="header">...</div>
<%= render :partial => "subnav" %>
<div id="content"><%= yield %></div>
<div id="footer">...</div>
Partial render. This is very similar to the helper method except perhaps the layout would have some if statements, or pass that off to a helper...
As for the content of your submenus, you can go at it in a declarative manner in each controller.
class PostsController < ApplicationController
#...
protected
helper_method :menu_items
def menu_items
[
['Submenu 1', url_for(me)],
['Submenu 2', url_for(you)]
]
end
end
Now whenever you call menu_items from a view, you'll have the right list to iterate over for the specific controller.
This strikes me as a cleaner solution than putting this logic inside view templates.
Note that you may also want to declare a default (empty?) menu_items inside ApplicationController as well.
Warning: Advanced Tricks ahead!
Render them all. Hide the ones that you don't need using CSS/Javascript, which can be trivially initialized in any number of ways. (Javascript can read the URL used, query parameters, something in a cookie, etc etc.) This has the advantage of potentially playing much better with your cache (why cache three views and then have to expire them all simultaneously when you can cache one?), and can be used to present a better user experience.
For example, let's pretend you have a common tab bar interface with sub navigation. If you render the content of all three tabs (i.e. its written in the HTML) and hide two of them, switching between two tabs is trivial Javascript and doesn't even hit your server. Big win! No latency for the user. No server load for you.
Want another big win? You can use a variation on this technique to cheat on pages which might but 99% common across users but still contain user state. For example, you might have a front page of a site which is relatively common across all users but say "Hiya Bob" when they're logged in. Put the non-common part ("Hiya, Bob") in a cookie. Have that part of the page be read in via Javascript reading the cookie. Cache the entire page for all users regardless of login status in page caching. This is literally capable of slicing 70% of the accesses off from the entire Rails stack on some sites.
Who cares if Rails can scale or not when your site is really Nginx serving static assets with new HTML pages occasionally getting delivered by some Ruby running on every thousandth access or so ;)
You could use something like the navigation plugin at http://rpheath.com/posts/309-rails-plugin-navigation-helper
It doesn't do sub-section navigation out of the box, but with a little tweaking you could probably set it up to do something similar.
I suggest you use partials. There are a few ways you can go about it. When I create partials that are a bit picky in that they need specific variables, I also create a helper method for it.
module RenderHelper
#options: a nested array of menu names and their corresponding url
def render_submenu(menu_items=[[]])
render :partial => 'shared/submenu', :locals => {:menu_items => menu_items}
end
end
Now the partial has a local variable named menu_items over which you can iterate to create your submenu. Note that I suggest a nested array instead of a hash because a hash's order is unpredictable.
Note that the logic deciding what items should be displayed in the menu could also be inside render_submenu if that makes more sense to you.
I asked pretty much the same question myself: Need advice: Structure of Rails views for submenus? The best solution was probably to use partials.
There is another possible way to do this: Nested Layouts
i don't remember where i found this code so apologies to the original author.
create a file called nested_layouts.rb in your lib folder and include the following code:
module NestedLayouts
def render(options = nil, &block)
if options
if options[:layout].is_a?(Array)
layouts = options.delete(:layout)
options[:layout] = layouts.pop
inner_layout = layouts.shift
options[:text] = layouts.inject(render_to_string(options.merge({:layout=>inner_layout}))) do |output,layout|
render_to_string(options.merge({:text => output, :layout => layout}))
end
end
end
super
end
end
then, create your various layouts in the layouts folder, (for example 'admin.rhtml' and 'application.rhtml').
Now in your controllers add this just inside the class:
include NestedLayouts
And finally at the end of your actions do this:
def show
...
render :layout => ['admin','application']
end
the order of the layouts in the array is important. The admin layout will be rendered inside the application layout wherever the 'yeild' is.
this method can work really well depending on the design of the site and how the various elements are organized. for instance one of the included layouts could just contain a series of divs that contain the content that needs to be shown for a particular action, and the CSS on a higher layout could control where they are positioned.
There are few approaches to this problem.
You might want to use different layouts for each section.
You might want to use a partial included by all views in a given directory.
You might want to use content_for that is filled by either a view or a partial, and called in the global layout, if you have one.
Personally I believe that you should avoid more abstraction in this case.