I've ran into another problem while outsourcing some notification logic to observers.
Is it possible to use simple_format inside of an observer?
I need it to transform text from database and strings from I18n.t into nice looking emails.
I found the solution by myself.
Just include the TextHelper-Module at the start of the file to use helpers like simple_format:
include ActionView::Helpers::TextHelper
class SystemmailerObserver < ActiveRecord::Observer
[...]
end
Related
I want to create a custom filter for auto_html. Where do I put the filter so I can use it?
The documentation doesn't touch on any of that. Thanks!
The approach I took was to add the code to an initializer file such as:
/path/to/your/application/config/initializers/auto_html.rb
Then you can just write something like:
AutoHtml.add_filter(:change_colours).with({}) do |text, options|
text.gsub("#FF0000", "#00FF00")
end
And call auto_html(input) { change_colours } in your model. The empty hash will take any options you care to pass to the filter.
Imagine i have a blog, and i want a footer or sidebar displaying my 3 most recent posts at any given time.
What is the best way to do this?
I can call #recent_posts in every single controller to have them ready for the layout but this doesn't seem like the best way...at all...
#recent_posts = Posts.all(:limit => 3)
I've been fiddling around with partials, but they do need an instance variable carrying the #recent_posts.
There may be two parts to your concern: 1) performance, and 2) effort required. Both are easily addressed.
As Andrei S notes in his answer, the convenience/effort issue is mitigated by using a before_filter that calls the method that does the work from the ApplicationController class.
The performance issue is only slightly more work. Instead of the method being
def most_recent_posts
Posts.order(created_at DESC).limit(3)
end
instead do this
def most_recent_posts
#most_recent_posts ||= Posts.order(created_at DESC).limit(3)
end
which checks the instance variable for nil; if nil, it does the query and assigns the result to the instance variable.
You'll also need a way to update when a new post is added, so perhaps something like
def clear_most_recent_posts!
#most_recent_posts = nil
end
and then just call clear_most_recent_posts! from the method(s) that modify the table. The before_filter will do its work only when needed.
I am sure some more eloquent rubyist has a nicer way of doing this, but this is an idea.
You could put the part where you have your posts in a partial and use it in the general layout of your app.
To load them all in every controller you could do a before_filter in your ApplicationController in which you set your instance variable, which will be available in your partial that gets rendered in the layout
This way you only get to do it once, and it will get done everywhere (of course you could set conditions on the filter and the layout to load them when you need, that's if you don't really need them on every page)
I have a mongoid document which embeds other documents with a relation like
this:
embeds_many :blocks
Creating new blocks works fine, but I cannot manage to change the
order of existing embedded documents. For example I have three
embedded blocks and I want to move the last one to the first
position.What's the correct way to do that?
I had to deal with this with mongoid's recursively_embeds_many feature, but it's essentially the same. There's nothing wrong as far as I can tell with literally rewriting the document. Write a model method to do something like:
def reverse_blocks
reversed_blocks = blocks.to_a.reverse
blocks.clear
reversed_blocks.each do |b|
blocks.create b.attributes
end
save
end
That's not great code above, but it gives you an idea of how to do what you want to do. I'm not thrilled with having to go through that just to reorder stuff in an array, but there it is.
I think, that really correct way is make in your embedded docs field "weight" and query them with asc(:weight) or desc(:weight). You don't rely on the order of persisted non-embedded docs, so you shouldn't in embedded.
But if you urgently need to make this, your embedded docs in mongoid are just array, so you can do such way:
doc.embedded_docs = [doc.embedded_docs.last] + doc.embedded_docs[0..-2]
I'm probably missing something obvious, but I've got a logo I'd like to include in all of the emails I send from my app. I have a master layout I'm using for all of those Mailers. I assume there's a way to do keep it DRY and not have to add the line of code to attach the file in every mailer method. Can someone point me in the right direction or correct my line of thought.
Thanks!
Callbacks using before_filter and after_filter will be supported in a future Rails release:
http://github.com/rails/rails/commit/4f28c4fc9a51bbab76d5dcde033c47aa6711339b
Since they will be implemented using AbstractController::Callbacks, you can do the following to mimic the functionality that will be present in ActionMailer::Base once Rails 4 is released:
class YourMailer < ActionMailer::Base
if self.included_modules.include?(AbstractController::Callbacks)
raise "You've already included AbstractController::Callbacks, remove this line."
else
include AbstractController::Callbacks
end
before_filter :add_inline_attachments!
private
def add_inline_attachments!
attachments.inline["footer.jpg"] = File.read('/path/to/filename.jpg')
end
end
This includes the module that will be used in a future rails version, so the callback hooks available to you will be the same to ensure future compatibility. The code will raise when you try to upgrade to a Rails version that already includes AbstractController::Callbacks, so you will be reminded to remove the conditional logic.
I hacked a little something, it's not ideal, but it works.
If you use
default "SOMEHEADER", Proc.new { set_layout }
And then define set_layout
def set_layout
attachments.inline["logo.png"] = File.read("logopath.png")
attachments.inline["footer.jpg"] = File.read("footerpath.png")
"SOME HEADER VALUE"
end
Then because set_layout gets called to set the header, it also adds the inline attachments. It basically creates a callback for adding attachments.
An actual callback system in ActionMailer would be preferable, but this works too.
Thought I would share since I was looking for this answer on this question earlier today.
in the layout file that your mailer uses u can add the following
<%= image_tag('logo.png') %>
I am assuming that the mail being sent out is html or multipart.
Also you will need to make changes in the environment files. ActionMailer does not get a default base_url. For e.g in environments/development.rb I added the following
config.action_mailer.default_url_options = { :host => "localhost:3000" }
If you want to do it in a dRY manner (and as an attachment) maybe you could do something like
class MyMailer < ActionMailer::Base
default :attachment => File.read(File.join(Rails.root,'public','images','logo.png'))
end
I know you've asked about attaching inline images, but here's a different approach that achieves the same thing with less complexity..
Using inline base64 encoded images in the html layout - no attachments required!
Basically just change the src="..." of your logo image to the format:
<img alt="example logo"
width="32px"
height="32px"
src="data:image/png;base64,iVBORw0KGgoAAA....."/>
I use the online base64 encoder / decoder tool at http://www.base64-image.net for generating the complete <img /> tag
This approach has a few benefits:
- no attachment code, which makes the backend server code cleaner and easier to read
- no increase in email size - inline image attachments are converted to base64 anyway so this approach doesn't make the email payload any larger
- it's widely supported - if the receiving email client is showing html, it's pretty likely it also supports this method
From a single view file containing e.g. LaTeX code with ERB inserts, I would like to be able to:
render to a LaTeX source file, by evaluating the ERB
render to PDF, by compiling the previous result using a custom latex_to_pdf() function
The first case can be achieved by registering a template handler:
ActionView::Template.register_template_handler :latex, LatexSource
where LatexSource is a subclass of ActionView::Template::Handler implementing call(template) or compile(template).
This allows a view file "action.tex.latex" to be accessed and processed correctly as "controller/action.tex".
The second case seems much harder though:
how can the request "controller/action.pdf" be sent to the template handler as if it was "controller/action.tex", and pass the result through latex_to_pdf() before sending the response to the user?
Many thanks
Couldn't you just register another template handler :pdf whose compile method looks similar to this?:
def compile
latex_to_pdf LatexSource.compile(template)
end
Update:
Ok, right, this results in the need of having the view duplicated (action.tex.latex, action.tex.pdf).
Next idea:
respond_to do |format|
format.latex
format.pdf { render :file => latex_to_pdf(render) }
end
As far as I can remember, render returned the rendered template as String in Rails 2.3.
I don't know how it behaves in Rails 3.
You could experiment with render or _render_template. If this works, we could think about how to make this more dry and comfortable for multiple actions.
I didn’t use it myself (yet), but it looks as if https://github.com/jacott/rails-latex could do the job for you.