#open = Array.new
#close = Array.new
#posts.each do |post|
if !post.status.nil? and post.status == 'Open'
#open.push(post)
else
#close.push(post)
end
end
Can i write it in less verbose way ?
Sounds like a job for partition:
partition { |obj| block } → [ true_array, false_array ]
partition → an_enumerator
Returns two arrays, the first containing the elements of enum for which the block evaluates to true, the second containing the rest.
This should do the job:
#open, #closed = #posts.partition { |p| p.status == 'Open' }
Another idea:
#open = #post.select{ |post| post.status == 'Open'}
#close = #post.reject{ |post| post.status == 'Open'}
You dont have to check nil explicity. Something like this will do.
#posts.each { |post| post.status == 'Open' ? #open.push post : #close.push }
Just to help you write code that's more Ruby-like, here's how I'd write your original code:
open_ary = []
close_ary = []
#posts.each do |post|
if post.status && post.status == 'Open'
open_ary << post
else
close_ary << post
end
end
It could be written more concisely, and would remove a couple lines, but it'd lose readability, which is always something to consider. That said, #muistooshort's answer is really the best way to do it because it relies on the partition method which was created for this sort of use-case.
Related
I'm new to Ruby and in various open source software I've noticed a number of "statements" in some RSpec descriptions that appear not to accomplish what they intended, like they wanted to make an assertion, but didn't. Are these coding errors or is there some RSpec or Ruby magic I'm missing? (Likelihood of weirdly overloaded operators?)
The examples, with #??? added to the suspect lines:
(rubinius/spec/ruby/core/array/permutation_spec.rb)
it "returns no permutations when the given length has no permutations" do
#numbers.permutation(9).entries.size == 0 #???
#numbers.permutation(9) { |n| #yielded << n }
#yielded.should == []
end
(discourse/spec/models/topic_link_spec.rb)
it 'works' do
# ensure other_topic has a post
post
url = "http://#{test_uri.host}/t/#{other_topic.slug}/#{other_topic.id}"
topic.posts.create(user: user, raw: 'initial post')
linked_post = topic.posts.create(user: user, raw: "Link to another topic: #{url}")
TopicLink.extract_from(linked_post)
link = topic.topic_links.first
expect(link).to be_present
expect(link).to be_internal
expect(link.url).to eq(url)
expect(link.domain).to eq(test_uri.host)
link.link_topic_id == other_topic.id #???
expect(link).not_to be_reflection
...
(chef/spec/unit/chef_fs/parallelizer.rb)
context "With :ordered => false (unordered output)" do
it "An empty input produces an empty output" do
parallelize([], :ordered => false) do
sleep 10
end.to_a == [] #???
expect(elapsed_time).to be < 0.1
end
(bosh/spec/external/aws_bootstrap_spec.rb)
it "configures ELBs" do
load_balancer = elb.load_balancers.detect { |lb| lb.name == "cfrouter" }
expect(load_balancer).not_to be_nil
expect(load_balancer.subnets.sort {|s1, s2| s1.id <=> s2.id }).to eq([cf_elb1_subnet, cf_elb2_subnet].sort {|s1, s2| s1.id <=> s2.id })
expect(load_balancer.security_groups.map(&:name)).to eq(["web"])
config = Bosh::AwsCliPlugin::AwsConfig.new(aws_configuration_template)
hosted_zone = route53.hosted_zones.detect { |zone| zone.name == "#{config.vpc_generated_domain}." }
record_set = hosted_zone.resource_record_sets["\\052.#{config.vpc_generated_domain}.", 'CNAME'] # E.g. "*.midway.cf-app.com."
expect(record_set).not_to be_nil
record_set.resource_records.first[:value] == load_balancer.dns_name #???
expect(record_set.ttl).to eq(60)
end
I don't think there is any special behavior. I think you've found errors in the test code.
This doesn't work because there's no assertion, only a comparison:
#numbers.permutation(9).entries.size == 0
It would need to be written as:
#numbers.permutation(9).entries.size.should == 0
Or using the newer RSpec syntax:
expect(#numbers.permutation(9).entries.size).to eq(0)
I am trying to do a post and run some if statement. What I want to do is:
check all fields are filled
if all fields are filled move on to next step, or else reload page
check if already in data base
add if not already in data base
post "/movies/new" do
title = params[:title]
year = params[:year]
gross = params[:gross]
poster = params[:poster]
trailer = params[:trailer]
if title && year && gross && poster && trailer
movie = Movie.find_by(title: title, year: year, gross: gross)
if movie
redirect "/movies/#{movie.id}"
else
movie = Movie.new(title: title, year: year, gross: gross, poster: poster, trailer: trailer)
if movie.save
redirect "/movies/#{movie.id}"
else
erb :'movies/new'
end
end
else
erb :'movies/new'
end
end
I don't think my if statement is correct. It works even if all my fields are not filled
Your code is doing a lot of work in one single method. I would suggest to restructure it into smaller chunks to make it easier to manage. I mostly code for Rails, so apologies if parts of these do not apply to your framework.
post "/movies/new" do
movie = find_movie || create_movie
if movie
redirect "/movies/#{movie.id}"
else
erb :'movies/new'
end
end
def find_movie
# guard condition to ensure that the required parameters are there
required_params = [:title, :year, :gross]
return nil unless params_present?(required_params)
Movie.find_by(params_from_keys(required_params))
end
def create_movie
required_params = [:title, :year, :gross, :poster, :trailer]
return nil unless params_present?(required_params)
movie = Movie.new(params_from_keys(required_params))
movie.save ? movie : nil # only return the movie if it is successfully saved
end
# utility method to check whether all provided params are present
def params_present?(keys)
keys.each {|key| return false if params[key].blank? }
true
end
# utility method to convert params into the hash format required to create / find a record
def params_from_keys(keys)
paras = {}
keys.each { |key| paras.merge!(key: params[key]) }
paras
end
Even if you type nothing in the HTML fields, they will still be submitted as empty strings.
You can avoid having empty parameters by, for example, filtering them:
post '/movies/new' do
params.reject! { |key, value| value.empty? }
# rest of your code
end
Also I would rather post to /movies rather than to /movies/new, that's more REST-wise.
Try if condition to check fields are blank like below -
unless [title, year, gross, poster, trailer].any?(&:blank?)
This will check any of the field should not be nil or blank("").
I have the following:
def self.parse_categories
categories = #data.css('#refinements ul').first
if categories.css('li:nth-child(1) a span').text == "Pet Supplies"
#categories_hash = {}
categories_category = categories.css('li:nth-child(2) strong').text
categories.css('li').drop(2).each do | categories |
categories_title = categories.css('.refinementLink').text
categories_count = categories.css('.narrowValue').text[/[\d,]+/].delete(",").to_i
#categories_hash[:categories] ||= {}
#categories_hash[:categories][categories_category] ||= {}
#categories_hash[:categories][categories_category][categories_title] = categories_count
end
else
#categories_hash = {}
end
return #categories_hash
end
Now the code works well in a page which has the element: #refinements ul But the code breaks in a page where there isn't. How can I do it so that nothing happens when there is no #refinements ul? Like ignoring the code without throwing an error or just skipping to else?
Like this, for example
def self.parse_categories
categories = #data.css('#refinements ul').first
return unless categories
# carry on
end
The problem is when #data.css('#refinements ul') is nil. Right?
So, try converting it to array and first.
categories = #data.css('#refinements ul').to_a.first
I am trying to build a simple nested html menu using HAML and am not sure how to go about inserting the elements with the correct indentation, or the general best way to build nested trees. I would like to be able to do something like this, but infinitely deep:
- categories.each_key do |category|
%li.cat-item{:id => "category-#{category}"}
%a{:href => "/category/#{category}", :title => "#{category.titleize}"}
= category.titleize
It feels like I should be able to accomplish this pretty easily without resorting to writing the tags by hand in html, but I'm not the best with recursion. Here is the code I've currently come up with:
View Helper
def menu_tag_builder(array, &block)
return "" if array.nil?
result = "<ul>\n"
array.each do |node|
result += "<li"
attributes = {}
if block_given?
text = yield(attributes, node)
else
text = node["title"]
end
attributes.each { |k,v| result += " #{k.to_s}='#{v.to_s}'"}
result += ">\n"
result += text
result += menu_tag_builder(node["children"], &block)
result += "</li>\n"
end
result += "</ul>"
result
end
def menu_tag(array, &block)
haml_concat(menu_tag_builder(array, &block))
end
View
# index.haml, where config(:menu) converts the yaml below
# to an array of objects, where object[:children] is a nested array
- menu_tag(config(:menu)) do |attributes, node|
- attributes[:class] = "one two"
- node["title"]
Sample YAML defining Menu
menu:
-
title: "Home"
path: "/home"
-
title: "About Us"
path: "/about"
children:
-
title: "Our Story"
path: "/about/our-story"
Any ideas how to do that so the output is like this:
<ul>
<li class='one two'>
Home
</li>
<li class='one two'>
About Us
</li>
</ul>
...not like this:
<ul>
<li class='one two'>
Home</li>
<li class='one two'>
About Us</li>
</ul>
... and so it's properly indented globally.
Thanks for the help,
Lance
The trick to nicely-indented, Ruby-generated Haml code is the haml_tag helper. Here's how I'd convert your menu_tag method to using haml_tag:
def menu_tag(array, &block)
return unless array
haml_tag :ul do
array.each do |node|
attributes = {}
if block_given?
text = yield(attributes, node)
else
text = node["title"]
end
haml_tag :li, text, attributes
menu_tag_builder(node["children"], &block)
end
end
end
How about something along the lines of:
def nested_list(list)
return unless list
haml_tag :ul do
list.each do |item|
haml_tag :li do
haml_concat link_to item["title"], item["path"]
if item["children"]
nested_list item["children"]
end
end
end
end
end
Awesome, #shingara's hint put me in the right direction :). This works perfectly:
def menu_tag(array, &block)
return "" if array.nil?
haml_tag :ui do
array.each do |node|
attributes = {}
if block_given?
text = yield(attributes, node)
else
text = node[:title]
end
haml_tag :li, attributes do
haml_concat text
menu_tag_builder(node[:children], &block)
end
end
end
end
If somebody can make that even shorter, or make it more easy to customize the attributes on the nested nodes, I'll mark that as correct instead of this.
Cheers.
It's because you send a pur HTML by your helper. The indentation become with HAML. You can can generate some HAML in your helper.
I've tried and tried, but I can't make this less ugly/more ruby-like. It seems like there just must be a better way. Help me learn.
class Df
attr_accessor :thresh
attr_reader :dfo
def initialize
#dfo = []
#df = '/opt/TWWfsw/bin/gdf'
case RUBY_PLATFORM
when /hpux/i
#fstyp = 'vxfs'
when /solaris/i
# fix: need /tmp too
#fstyp = 'ufs'
when /linux/i
#df = '/bin/df'
#fstyp = 'ext3'
end
#dfo = parsedf
end
def parsedf
ldf = []
[" "," -i"] .each do |arg|
fields = %w{device size used avail capp mount}
fields = %w{device inodes inodesused inodesavail iusep mount} if arg == ' -i'
ldf.push %x{#{#df} -P -t #{#fstyp}#{arg}}.split(/\n/)[1..-1].collect{|line| Hash[*fields.zip(line.split).flatten]}
end
out = []
# surely there must be an easier way
ldf[0].each do |x|
ldf[1].select { |y|
if y['device'] == x['device']
out.push x.merge(y)
end
}
end
out
end
end
In my machine, your ldf array after the df calls yields the following:
irb(main):011:0> ldf
=> [[{"device"=>"/dev/sda5", "size"=>"49399372", "mount"=>"/", "avail"=>"22728988", "used"=>"24161036", "capp"=>"52%"}], [{"device"=>"/dev/sda5", "inodes"=>"3137536", "mount"=>"/", "iusep"=>"13%", "inodesavail"=>"2752040", "inodesused"=>"385496"}]]
The most flexible approach to merging such a structure is probably something along these lines:
irb(main):013:0> ldf.flatten.inject {|a,b| a.merge(b)}
=> {"device"=>"/dev/sda5", "inodes"=>"3137536", "size"=>"49399372", "mount"=>"/", "avail"=>"22728988", "inodesavail"=>"2752040", "iusep"=>"13%", "used"=>"24161036", "capp"=>"52%", "inodesused"=>"385496"}
Some ruby programmers frown on this use of inject, but I like it, so your mileage may vary.
As for helping making your code more ruby like, I suggest you talk to some experienced rubyist you might know over your code to help you rewriting it in a way that follows good style and best practices. Probably that would the preferable than to just have someone rewrite it for you here.
Best of Luck!
Didn't test the code, but here goes:
ARGUMENTS = {
" " => %w{size used avail capp mount},
" -i" => %w{inodes inodesused inodesavail iusep mount}
}
def parsedf
# Store resulting info in a hash:
device_info = Hash.new do |h, dev|
h[dev] = {} # Each value will be a empty hash by default
end
ARGUMENTS.each do |arg, fields|
%x{#{#df} -P -t #{#fstyp}#{arg}}.split(/\n/)[1..-1].each do |line|
device, *data = line.split
device_info[device].merge! Hash[fields.zip(data)]
end
end
device_info
end
Notes: returns something a bit different than what you had:
{ "/dev/sda5" => {"inodes" => "...", ...},
"other device" => {...}
}
Also, I'm assuming Ruby 1.8.7 or better for Hash[key_value_pairs], otherwise you can resort to the Hash[*key_value_pairs.flatten] form you had
Depending on your needs, you should consider switch the fields from string to symbols; they are the best type of keys.