How to pass size param to carrierwave helper? - ruby-on-rails-3

Im trying to make 1 global function to display carrier wave images in different sizes. the problem is passing the size var in method call to the carrierwave helper like below:
def get_avatar(id, size)
#profile = User.find(id).profile rescue nil
image_tag #profile.photos.first.file_url(:img_120x145)
rescue
image_tag ("/assets/avatars/img_#{size}.png")
end
I tried all kinds of things but are unable to pass the size var to the #profile.photos.first_url(size here).
How should one approach this?

Heres what worked for me recently.
<% image_tag #profile.photos.first.url(size) %>

Related

how to append/replace alt/title attribute in all image tags?

say I have an action template like this
# home/index.html.erb
<%= img_tag "logo.gif" %>
if I want to add alt/title attribute to it, I can just do
# home/index.html.erb
<%= img_tag "logo.gif", alt: "alt!!", title: "title!!" %>
but I have 1000 image tags and I don't want to change every each one of them.
I then thought of using rack middleware and modify image tags before outputting from server.
http://railscasts.com/episodes/151-rack-middleware?view=asciicast
doc = Nokogiri.HTML(#response.body)
doc.search("img").each do |tag|
[:alt, :title].each{|attribute| tag[attribute] = "changed!!" }
end
but when I follow the railscast episode, it appends entire body on the top of the original rather than replacing it.
Am I doing it wrong in the rack, or is there a smarter way to do this?
Updated answer:
# /config/initializers/image_tag_helper.rb
module ActionView
module Helpers
module AssetTagHelper
def image_tag(source, options={})
options[:src] = path_to_image(source)
options[:alt] = "Default Alt" unless options.has_key?(:alt)
options[:title] = "Default Title" unless options.has_key?(:title)
tag(:img, options)
end
end
end
end
This overrides the image_tag helper method to set default alt and title attributes.

How to get the current view name from layout template in Rails?

Is it possible to get the name of the currently rendered view from inside layout?
I did something like this for css namespacing:
# config/initializers/action_view.rb
ActionView::TemplateRenderer.class_eval do
def render_template_with_tracking(template, layout_name = nil, locals = {})
# with this gsub, we convert a file path /folder1/folder2/subfolder/filename.html.erb to subfolder-filename
#view.instance_variable_set(:#_rendered_template, template.inspect.gsub(/(\..*)/, '').split('/')[-2..-1].join('-'))
out = render_template_without_tracking(template, layout_name, locals)
#view.instance_variable_set(:#_rendered_template, nil)
return out
end
alias_method_chain :render_template, :tracking
end
# application.html.erb
<body class="<%= :#_rendered_template %>" >
Use <% __FILE__ %> to get the complete file path of current view, but you can only use it from within the file itself without writing some helpers
The method active_template_virtual_path method returns the template as a name in the following form "controller/action"
class ActionController::Base
attr_accessor :active_template
def active_template_virtual_path
self.active_template.virtual_path if self.active_template
end
end
class ActionView::TemplateRenderer
alias_method :_render_template_original, :render_template
def render_template(template, layout_name = nil, locals = {})
#view.controller.active_template = template if #view.controller
result = _render_template_original( template, layout_name, locals)
#view.controller.active_template = nil if #view.controller
return result
end
end
I had a similar question. I found <%= params[:controller] %> and <%= params[:action] %> to suit my need, which was to add the controller name and action name as classes on the body tag.
Just in case that helps anyone. :)
I'm currently using a modified version of Peter Ehrlich's solution. The resulting string is of the form controller_name/view_name, e.g. users/new, which means it can be passed directly to render later on, or altered to suit other uses. I've only tried this with Rails 4.2, though as far as I know it ought to work all the way back into the 3.xes.
ActionView::Base.class_eval do
attr_accessor :current_template
end
ActionView::TemplateRenderer.class_eval do
def render_template_with_current_template_accessor(template, layout_name = nil, locals = {})
#view.current_template = template.try(:virtual_path)
render_template_without_current_template_accessor(template, layout_name, locals)
end
alias_method_chain :render_template, :current_template_accessor
end
For debugging purpose, you can use gem 'current_template' from here.
This gem inspects logfile and display file name of view/partial template.
For example:
Also, you can simply add this line
<%= "#{`tail log/development.log`}".scan(/\s[a-z]+\/\S+/) %>
to your layout/application.html.erb.

Rails and named_scope queries

I'm trying to get my head around the concept of named_scoped queries in rails.
I'm trying to filter a table to get only non featured items (:featured => false).
In my model i have added
scope :allgames, where(:featured => false)
and
scope :featured, where(featured => true)
I'm trying to list all featured and non featured items separately on my Game index page.
Is it possible to to it via a named scope.
So far i have:
<% #games.each do |item| %>
<% if item.featured %>
<%= render 'application/item_synopsis_builder', item: item %>
<% end -%>
<% end %>
And I wonder if it is possible to do something like:
<% #games.featured.each do |item| %>
<%= render 'application/item_synopsis_builder', item: item %>
<% end %>
or
<%= render partial: 'application/item_synopsis_builder', collection: #games.featured %>
When I try I get a message saying that there is no method featured.
But when I run the command Game.featured in the console I get the result list of all featured games.
Is it possible to access this list/method in the view?
Named scopes are added to the model as a class method, so trying to access the method on a collection of objects won't work. Similar functionality can be achieved with:
#games.where(:featured => true).each do
...
end
But I would recommend having two variables in your controller:
#featured_games = Games.featured
#all_games = Games.allgames
then use those in your views.
Your views are driven by the #games instance variable that is created by the controller that is rendering the views. Named scopes create a class method for subclasses of ActiveRecord::Base. So "Game.featured" returns something because defining the named scope created a method for the Game class. It did not create an instance method that objects of the Game class (such as #games) can invoke. That's why "#games.featured" gives you an error.
To do what you want to do, create two instance variable in the controller and pass them to the view, e.g.
#all_games = Game.allgames
#featured_games = Game.featured
Both variables will be available to your view, and you can construct loops to render each collection however you like.
A scope is a class method (or assimilable to, I don't know the specifics), so yes, Game.featured would work, but when you do #games.featured, you are calling featured on an array of Game instances.

Rails 3: Will_paginate's .paginate doesn't work

I'm using newes Rails 3 version with will_paginate.
#videos = user.youtube_videos.sort.paginate :page => page
I also added the ##per_page attribute to my youtube_video-model.
But it just won't paginate it. I get always all items in the collection listed.
What have I done wrong?
Yours, Joern.
Why are you calling sort here? That seems unnecessary, and probably would result in it finding all videos and calling pagination on that rather than paying any attention to any variable defined in your Video model. Instead, move the sorting logic into the Video model by using a scope or use the order method.
Here's my solution, my own answer, for all other's having trouble with will_paginate and reading this issue:
Create an ApplicationController method like this:
def paginate_collection(collection, page, per_page)
page_results = WillPaginate::Collection.create(page, per_page, collection.length) do |pager|
pager.replace(collection)
end
collection = collection[(page - 1) * per_page, per_page]
yield collection, page_results
end
Then in your Controller, where you got the collection that should be paginated:
page = setup_page(params[:page]) # see below
#messages = Message.inbox(account)
paginate_collection(#messages, page, Message.per_page) do |collection, page_results|
#messages = collection
#page_results = page_results
end
And in your View:
<% #messages.each do |message| %>
<%# iterate and show message titles or whatever %>
<% end %>
<%= will_paginate #page_results %>
To get the page variable defined, check this:
def setup_page(page)
if !page.nil?
page.to_i
else
1
end
end
So page = setup_page(params[:page]) does the trick, with that simple method.
This WORKS!

Rails 3 Rendering Binary Content

I need to render binary content(images) on web page. I'm saving images in the database with datatype binary. Now I need to iterate available images from the database and render on webpage.
Please check the below code that I'm doing. Icon is the image column name in material.
// iterating all materials
<% #materials.each do |material| %>
// for each material
<span><%= image_tag(material.icon) %></span>
<% end %>
Any help would be greatly appreciated..
You need to add an action to your controller along these lines (cribbed from here):
def image
#material = Material.find(params[:id])
send_data #material.icon, :type => 'image/png',:disposition => 'inline'
end
Then call the path to that action in your image_tag. You obviously need to make sure the :type field has the right MIME type, add a route, etc.