What does a Ruby string wrapped in _() mean? - ruby

I'm looking at a Sinatra app for a CAS server for SSO. I'm unsure what the underscore and parentheses mean in the string assignment. Here's a sample line:
#message = {:type => 'confirmation', :message => _("You have successfully logged in.")}
But it's also used in ERB:
<%= _("Username") %>

_ is the name of the translation method of GetText.
So _ basically means: Take the following string and use it as a key to find a localized/translated version.

Related

How to replace words inside template placeholders

I'm trying to write a regular expression to replace <%= Name %> with "Some Person".
I'm using a regex because I want to modify it so that I don't have to worry about the spaces between = and Name as well as the E in Name and the %>
I tried:
body = %q(
Hello <%= Name %>,
This is a test. hello test
some more stuff here
and here.
<%= Name %>
)
parsed_body = body.gsub(/\A<%= Name %>\Z/, "Some person")
puts parsed_body
When parsed_body is printed out, the string is unchanged. What is wrong with my regex?
In your Regex, you have added the \A and \z anchors. These ensure that your regex only matches, if the string only contains exactly <%= Name %> with nothing before or after.
To match the your pattern anywhere in the string, you can simply remove the anchors:
parsed_body = body.gsub(/<%= Name %>/, "Some person")
Just another option considering what I am assuming you are trying to accomplish
tag_pattern = /(?<open_tag><%=\s*)(?<key>(\w+))(?<close_tag>\s*%>)/
body = <<-B
Hello,
My name is <%= Name %> and I know some things. Just because I am a
<%= Occupation %> doesn't mean I know everything, but I sure can
<%=Duty%> just as well as anyone else.
Also please don't replace <%= This %>
Thank you,
<%= Name %>
B
dict = {"Name" => "engineersmnky", "Occupation" => "Monkey", "Duty" => "drive a train"}
body.gsub(tag_pattern) {|m| dict[$2] || m }
#=> Hello,
# My name is engineersmnky and I know some things. Just because I am a
# Monkey doesn't mean I know everything, but I sure can
# drive a train just as well as anyone else.
# Also please don't replace <%= This %>
#
# Thank you,
# engineersmnky
In this case I used a dictionary of the anticipated portions of the "erb" to be replaced and used the block style of String#gsub to handle the replacements where $2 is the named capture key. When there is not a matching key it just leaves the match untouched e.g. "Also please don't replace <%= This %>"
You could implement this with any pattern you choose but if you are going to use "erb" style lines maybe try leveraging erb other wise the same will work below:
tag_pattern = (?<open_tag>{!!\s*)(?<key>(\w+))(?<close_tag>\s*!\?})
body = <<-B Hello,
My name is {!! Name !?} and I know some things. Just because I am a
{!! Occupation !?} doesn't mean I know everything, but I sure can
{!!Duty !?} just as well as anyone else.
Thank you,
{!! Name !?}
B
As long as you define tag_pattern correctly the replacement is fairly simple. Rubular Example
It looks like you're trying to write your own template parser, which is asking for a lot more trouble that it's worth considering those already exist.
However, this is the basic idea for such a thing:
erb = <<EOT
Owner: <%= name %>
Location: <%= address %>
EOT
FIELD_DATA = {
name: 'Olive Oyl',
address: '5 Sweethaven Village'
}
FIELD_RE = Regexp.union(FIELD_DATA.keys.map(&:to_s)).source # => "name|address"
puts erb.gsub(/<%=\s+(#{FIELD_RE})\s+%>/) { |k|
k # => "<%= name %>", "<%= address %>"
k[/\s+(\S+)\s+/, 1] # => "name", "address"
FIELD_DATA[k[/\s+(\S+)\s+/, 1].to_sym] # => "Olive Oyl", "5 Sweethaven Village"
}
Which, when run, outputs:
Owner: Olive Oyl
Location: 5 Sweethaven Village
This works because gsub can take a regular expression and a block. For every match of the expression it passes in the match to the block, which is then used to return the actual value being substituted in.
If you have a lot of target values, rather than use Regexp.union, instead use the RegexpTrie gem. See "Is there an efficient way to perform hundreds of text substitutions in Ruby?" for more information.
Again, template parsers exist, they've been around a long time, they're very well tested, and they handle edge cases you haven't thought about, so don't write a new partially-implemented one, instead reuse an existing one.

Ruby Blather gem, trying to downcase input

I am using Blather to make a chatbot.
I am taking this example from the documentation:
message :chat?, :body => 'hello' do |m|
say m.from, 'world'
end
but I would like it to account for ANY 'case' of hello, i.e. hEllo, HELLO, Hello, and respond with world.
How would I go about doing that?
You should be able to use a regular expression. In this case, just make a simple case-insensitive match:
message :chat?, :body => /hello/i do |m|
# ... etc
If you'll read the "guards" documentation you'll see:
# Hash with regular expression (:body => /exit/)
# Calls the key on the stanza and checks for a match
# Equivalent to stanza.body.match /exit/
message :body => /exit/

Instantiating Devise user models manually using contents of params hash

I'm losing my mind trying to figure this out:
There's a registration module which side-steps the main devise registrations controller, and I have to manually instantiate the Devise-generated user model using User.new(...). I'm using a form_tag to submit all of the necessary parameters necessary for User.new(). Here's a truncated version of my code:
def registration_three
#user = User.new(:email => params[:email], :password => params[:password], :password_confirmation => params[:password_confirmation])
#user.save
#user = User.new(:email => 'patlopez#yahoo.com', :password => 'qwertyui', :password_confirmation => 'qwertyui')
#user.save
end
The second #user.save works, but the first one doesn't. params[:email], params[:password], and params[:password_confirmation] certainly exist, according to the print statements in stdout.
Anyone have any ideas?
EDIT:
So I tried changing all of the single-quote strings in the second User.new(...) to double-quote strings like the ones stored in the params hash...and the second instantiation failed as well. So I'm fairly sure that the issue involves double- vs single-quote strings. Anyone know how to convert double-quote strings to single-quote ones? Thanks in advance.
Store your params in variable first then use them in query to avoid quote errors

Is sprintf incompatible with sinatra?

Say I have this:
class Account
...
property :charge, Decimal, :precision => 7, :scale => 2
...
classy stuff
...
def self.balance(prefix)
x = Account.get(prefix.to_sym).order(:fields => [:charge]).sum(:charge)
sprintf("%5.2f", x)
end
end
(Edit: The value of all :charge fields is 0.13E2 (0.1E2 + 0.3E1). This is correctly returned. Only in a View does it seem to get borked from sprintf)
In IRB Account.balance(:AAA) returns => "13.00"
if I call Account.balance(:AAA) from a view I get TypeError at /accounts
can't convert nil into Float
Account.balance(:AAA) works anywhere I call it except in a view. If I remove sprintf("%5.2f", x) I get 0.13E2 in my view. (using Account.balance(:AAA).to_f in a view gives me 13.0)
Is sinatra incompatible with sprintf? or am I not understanding how to use sprintf?
(Edit: This is the offending view:)
<section>
<% #accounts.each do |account| %>
<article>
<h2><%= account.prefix %></h2>
<span><p>This account belongs to <%= account.name %> & has a balance of $<%= Account.balance(account.prefix) %>.</p></span>
</article>
<% end %>
</section>
Wouldn't it make more sense to define balance as an instance method rather than a class method? It looks from your example like you're calling balance in an account-specific way anyway, so why not make it:
# the model
class Account
#...
def balance
amount = self.order(:fields => [:charge]).sum(:charge)
sprintf "%5.2f", amount
# or the infix version:
"%5.2f" % amount
end
end
,
# the view
...balance of $<%= account.balance %>...
I know that this doesn't address sprintf per se, but the problem is more likely to be coming from the slightly convoluted lookup than from a built-in method. Even if my specific code doesn't suit your application, it might be worth simplifying the lookup step, even if that involves a few more lines of code.
The advantage of this approach is that there is no doubt that you'll be getting the right Account record.
tested it with a little sinatra app and it worked for me
app.rb
#!/usr/bin/env ruby
require 'rubygems'
require 'sinatra'
get '/' do
#x = 10.23
erb :index
end
views/index.erb
<%= sprintf("%5.2f", #x) %>
output:
10.23
ruby 1.9.2 / sinatra 1.3.1
I think there is another error before the sprintf because of your error message:
can't convert nil into Float
seems like your x is nil. try to be sure that x is not nil there, then sprintf should work as expected.

Ruby on Rails - Truncate to a specific string

Clarification: The creator of the post should be able to decide when the truncation should happen.
I implemented a Wordpress like [---MORE---] functionality in my blog with following helper function:
# application_helper.rb
def more_split(content)
split = content.split("[---MORE---]")
split.first
end
def remove_more_tag(content)
content.sub(“[---MORE---]", '')
end
In the index view the post body will display everything up to (but without) the [---MORE---] tag.
# index.html.erb
<%= raw more_split(post.rendered_body) %>
And in the show view everything from the post body will be displayed except the [---MORE---] tag.
# show.html.erb
<%=raw remove_more_tag(#post.rendered_body) %>
This solution currently works for me without any problems.
Since I am still a beginner in programming I am constantly wondering if there is a more elegant way to accomplish this.
How would you do this?
Thanks for your time.
This is the updated version:
# index.html.erb
<%=raw truncate(post.rendered_body,
:length => 0,
:separator => '[---MORE---]',
:omission => link_to( "Continued...",post)) %>
...and in the show view:
# show.html.erb
<%=raw (#post.rendered_body).gsub("[---MORE---]", '') %>
I would use just simply truncate, it has all of the options you need.
truncate("And they found that many people were sleeping better.", :length => 25, :omission => '... (continued)')
# => "And they f... (continued)"
Update
After sawing the comments, and digging a bit the documentation it seems that the :separator does the work.
From the doc:
Pass a :separator to truncate text at a natural break.
For referenece see the docs
truncate(post.rendered_body, :separator => '[---MORE---]')
On the show page you have to use gsub
You could use a helper function on the index page that only grabs the first X characters in your string. So, it would look more like:
<%= raw summarize(post.rendered_body, 250) %>
to get the first 250 characters in your post. So, then you don't have to deal w/ splitting on the [---MORE---] string. And, on the show page for your post, you won't need to do anything at all... just render the post.body.
Here's an example summarize helper (that you would put in application_helper.rb):
def summarize(body, length)
return simple_format(truncate(body.gsub(/<\/?.*?>/, ""), :length => length)).gsub(/<\/?.*?>/, "")
end
I tried and found this one is the best and easiest
def summarize(body, length)
return simple_format = body[0..length]+'...'
end
s = summarize("to get the first n characters in your post. So, then you don't have to deal w/ splitting on the [---MORE---] post.body.",20)
ruby-1.9.2-p290 :017 > s
=> "to get the first n ..."

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