Have a small method in a Padrino helper to add partials. There are two main uses for it:
Have an easily configurable enable/disable system via a config file for the components.
Choose language specific layouts IF the requested layout is not found.
This is the code, I am using:
module SZHF
App.helpers do
def add_component component
if disabled?(component)
""
else
begin
partial(component)
rescue
language_specific(component)
end
end
end
def partial_exists?(component)
File.file?(File.expand_path("../../views/#{component}.html.erb", __FILE__))
end
def disabled?(component)
name = component.split("/").last
config["enable_#{name}".to_sym] == false
end
def language_specific(component)
name = component.split("/").last
prefix = component.chomp(name)
partial prefix + I18n.locale.to_s + "/" + name
end
end
end
But somehow the error instead being caught in the rescue block; the page returns an error stating: undefined methodsafe_concat' for nil:NilClass`.
Can't figure out why, any ideas?
Related
I'm trying to implement a file dialog using Tk. This aspect has worked but my error checking isn't working.
Since this file dialog can only take certain extensions I made it raise a LoadError, but I also don't want the program to stop, I want it to reopen to allow the user to pick another file.
Each way I've tried has only ended in an infinite loop or a LoadError stopping the program.
My code is:
module FileExplorer
require 'tk'
require 'tkextlib/tile'
def self.fileDialog
TkClipboard.append(Tk.getOpenFile)
f = TkClipboard.get
begin
unless extenstionCheck(f)
raise LoadError, 'Please select a valid file type'
end
rescue LoadError
fileDialog
end
end
def self.extenstionCheck(file)
filetypes = ['.xlsx', '.xls', '.csv', '.xml']
type = File.extname(file)
true if filetypes.include?(file)
end
end
There's no need to use TkClipboard, nor to use an exception.
Did misspelling the word, 'extension' blind you to your nearby error of checking whether filetypes included file, instead of type?
Your program, minimally changed as follows, works for me:
module FileExplorer
require 'tk'
require 'tkextlib/tile'
def self.fileDialog
while true
f = Tk.getOpenFile
break if extension_okay?(f)
Tk.messageBox message: 'Please select a valid file type!', detail: "Selection was: #{f}"
end
f
end
def self.extension_okay?(file)
filetypes = ['.xlsx', '.xls', '.csv', '.xml']
type = File.extname(file)
filetypes.include?(type)
end
end
p FileExplorer.fileDialog
This is completely inappropriate (and unnecessary) use of LoadError.
Raised when a file required (a Ruby script, extension library, …)
fails to load.
Its a low level error that does not inherit from StandardError and is tied to Kernel#require.
Instead declare your own exceptions in your own namespace:
module FileExplorer
require 'tk'
require 'tkextlib/tile'
FileTypeError = Class.new(::StandardError)
def self.fileDialog
TkClipboard.append(Tk.getOpenFile)
f = TkClipboard.get
begin
unless extenstionCheck(f)
raise FileTypeError, 'Please select a valid file type'
end
rescue FileTypeError
fileDialog
end
end
def self.extenstionCheck(file)
filetypes = ['.xlsx', '.xls', '.csv', '.xml']
type = File.extname(file)
true if filetypes.include?(file)
end
end
I'm trying to override the after_failed_example method so I can inflict some custom file naming on our screenshots. I'm loading the module as an initializer.
So far, so good, but the Capybara.page.current_url is blank, making me think I need to require something additional?
require "capybara-screenshot/rspec"
module Capybara
module Screenshot
module RSpec
class << self
attr_accessor :use_description_as_filename
attr_accessor :save_html_file
end
self.use_description_as_filename = true
self.save_html_file = true
def self.after_failed_example(example)
if example.example_group.include?(Capybara::DSL) # Capybara DSL method has been included for a feature we can snapshot
Capybara.using_session(Capybara::Screenshot.final_session_name) do
puts ">>>> Capybara.page.current_url: " + Capybara.page.current_url.to_s
if Capybara::Screenshot.autosave_on_failure && failed?(example) && Capybara.page.current_url != ''
saver = Capybara::Screenshot.new_saver(Capybara, Capybara.page, Capybara::Screenshot.save_html_file?, set_saver_filename_prefix(example))
saver.save
example.metadata[:screenshot] = {}
example.metadata[:screenshot][:html] = saver.html_path if saver.html_saved?
example.metadata[:screenshot][:image] = saver.screenshot_path if saver.screenshot_saved?
end
end
end
private
def self.set_saver_filename_prefix(example)
return example.description.to_s.gsub(" ", "-") if Capybara::Screenshot.use_description_as_filename?
return Capybara::Screenshot.filename_prefix_for(:rspec, example)
end
end
end
end
end
This is successfully overriding the capybara-screenshot/rspec method, and any of the Capybara::Screenshot static information is accessible, but not Capybara session related information (afa I can tell).
For example, Capybara.page.current_url.to_s is null when overridden, but present when not.
I was missing a require (kind of silly mistake):
require 'capybara/rspec'
I am building a simple web spider using Sidekiq and Mechanize.
When I run this for one domain, it works fine. When I run it for multiple domains, it fails. I believe the reason is that web_page gets overwritten when instantiated by another Sidekiq worker, but I am not sure if that's true or how to fix it.
# my scrape_search controller's create action searches on google.
def create
#scrape = ScrapeSearch.build(keywords: params[:keywords], profession: params[:profession])
agent = Mechanize.new
scrape_search = agent.get('http://google.com/') do |page|
search_result = page.form...
search_result.css("h3.r").map do |link|
result = link.at_css('a')['href'] # Narrowing down to real search results
#domain = Domain.new(some params)
ScrapeDomainWorker.perform_async(#domain.url, #domain.id, remaining_keywords)
end
end
end
I'm creating a Sidekiq job per domain. Most of the domains I'm looking for should contain just a few pages, so there's no need for sub-jobs per page.
This is my worker:
class ScrapeDomainWorker
include Sidekiq::Worker
...
def perform(domain_url, domain_id, keywords)
#domain = Domain.find(domain_id)
#domain_link = #domain.protocol + '://' + domain_url
#keywords = keywords
# First we scrape the homepage and get the first links
#domain.to_parse = ['/'] # to_parse is an array of PATHS to parse for the domain
mechanize_path('/')
#domain.verified << '/' # verified is an Array field containing valid domain paths
get_paths(#web_page) # Now we should have to_scrape populated with homepage links
#domain.scraped = 1 # Loop counter
while #domain.scraped < 100
#domain.to_parse.each do |path|
#domain.to_parse.delete(path)
#domain.scraped += 1
mechanize_path(path) # We create a Nokogiri HTML doc with mechanize for the valid path
...
get_paths(#web_page) # Fire this to repopulate to_scrape !!!
end
end
#domain.save
end
def mechanize_path(path)
agent = Mechanize.new
begin
#web_page = agent.get(#domain_link + path)
rescue Exception => e
puts "Mechanize Exception for #{path} :: #{e.message}"
end
end
def get_paths(web_page)
paths = web_page.links.map {|link| link.href.gsub((#domain.protocol + '://' + #domain.url), "") } ## This works when I scrape a single domain, but fails with ".gsub for nil" when I scrape a few domains.
paths.uniq.each do |path|
#domain.to_parse << path
end
end
end
This works when I scrape a single domain, but fails with .gsub for nil for web_page when I scrape a few domains.
You can wrap you code in another class, and then create and object of that class within your worker:
class ScrapeDomainWrapper
def initialize(domain_url, domain_id, keywords)
# ...
end
def mechanize_path(path)
# ...
end
def get_paths(web_page)
# ...
end
end
And your worker:
class ScrapeDomainWorker
include Sidekiq::Worker
def perform(domain_url, domain_id, keywords)
ScrapeDomainWrapper.new(domain_url, domain_id, keywords)
end
end
Also, bear in mind that Mechanize::Page#links may be a nil.
I need to:
Open a Rakefile
Find if a certain task is defined
Find if a certain variable is defined
This works to find tasks defined inside a Rakefile, but it pollutes the global namespace (i.e. if you run it twice, all tasks defined in first one will show up in the second one):
sub_rake = Rake::DefaultLoader.new
sub_rake.load("Rakefile")
puts Rake.application.tasks
In Rake, here is where it loads the Makefile:
https://github.com/ruby/rake/blob/master/lib/rake/rake_module.rb#L28
How do I get access to the variables that are loaded there?
Here is an example Rakefile I am parsing:
load '../common.rake'
#source_dir = 'source'
desc "Run all build and deployment tasks, for continuous delivery"
task :deliver => ['git:pull', 'jekyll:build', 'rsync:push']
Here's some things I tried that didn't work. Using eval on the Rakefile:
safe_object = Object.new
safe_object.instance_eval("Dir.chdir('" + f + "')\n" + File.read(folder_rakefile))
if safe_object.instance_variable_defined?("#staging_dir")
puts " Staging directory is " + f.yellow + safe_object.instance_variable_get("#staging_dir").yellow
else
puts " Staging directory is not specified".red
end
This failed when parsing desc parts of the Rakefile. I also tried things like
puts Rake.instance_variables
puts Rake.class_variables
But these are not getting the #source_dir that I am looking for.
rakefile_body = <<-RUBY
load '../common.rake'
#source_dir = 'some/source/dir'
desc "Run all build and deployment tasks, for continuous delivery"
task :deliver => ['git:pull', 'jekyll:build', 'rsync:push']
RUBY
def source_dir(ast)
return nil unless ast.kind_of? AST::Node
if ast.type == :ivasgn && ast.children[0] == :#source_dir
rhs = ast.children[1]
if rhs.type != :str
raise "#source_dir is not a string literal! #{rhs.inspect}"
else
return rhs.children[0]
end
end
ast.children.each do |child|
value = source_dir(child)
return value if value
end
nil
end
require 'parser/ruby22'
body = Parser::Ruby22.parse(rakefile_body)
source_dir body # => "some/source/dir"
Rake runs load() on the Rakefile inside load_rakefile in the Rake module. And you can easily get the tasks with the public API.
Rake.load_rakefile("Rakefile")
puts Rake.application.tasks
Apparently that load() invocation causes the loaded variables to be captured into the main Object. This is the top-level Object of Ruby. (I expected it to be captured into Rake since the load call is made in the context of the Rake module.)
Therefore, it is possible to access instance variables from the main object using this ugly code:
main = eval 'self', TOPLEVEL_BINDING
puts main.instance_variable_get('#staging_dir')
Here is a way to encapsulate the parsing of the Rakefile so that opening two files will not have all the things from the first one show up when you are analyzing the second one:
class RakeBrowser
attr_reader :tasks
attr_reader :variables
include Rake::DSL
def task(*args, &block)
if args.first.respond_to?(:id2name)
#tasks << args.first.id2name
elsif args.first.keys.first.respond_to?(:id2name)
#tasks << args.first.keys.first.id2name
end
end
def initialize(file)
#tasks = []
Dir.chdir(File.dirname(file)) do
eval(File.read(File.basename(file)))
end
#variables = Hash.new
instance_variables.each do |name|
#variables[name] = instance_variable_get(name)
end
end
end
browser = RakeBrowser.new(f + "Rakefile")
puts browser.tasks
puts browser.variables[:#staging_dir]
I have following code:
module DataMapper
module Resource
##page_size = 25
attr_accessor :current_page
attr_accessor :next_page
attr_accessor :prev_page
def first_page?
#prev_page
end
def last_page?
#next_page
end
def self.paginate(page)
if(page && page.to_i > 0)
#current_page = page.to_i - 1
else
#current_page = 0
end
entites = self.all(:offset => #current_page * ##page_size, :limit => ##page_size + 1)
if #current_page > 0
#prev_page = #current_page
end
if entites.size == ##page_size + 1
entites.pop
#next_page = (#current_page || 1) + 2
end
entites
end
end
end
Then I have call of #paginate:
#photos = Photo.paginate(params[:page])
And getting following error:
application error
NoMethodError at /dashboard/photos/
undefined method `paginate' for Photo:Class
In Active record this concept works fine for me... I'am using JRuby for notice. What I'am doing wrong?
Andrew,
You can think of DataMapper::Resource as the instance (a row) and of DataMapper::Model as the class (a table). Now to alter the default capabilities at either the resource or the model level, you can either append inclusions or extensions to your model.
First you will need to wrap your #paginate method in a module. I've also added a probably useless #page method to show how to append to a resource in case you ever need to.
module Pagination
module ClassMethods
def paginate(page)
# ...
end
end
module InstanceMethods
def page
# ...
end
end
end
In your case, you want #paginate to be available on the model, so you would do:
DataMapper::Model.append_extensions(Pagination::ClassMethods)
If you find yourself in need of adding default capabilities to every resource, do:
DataMapper::Model.append_inclusions(Pagination::InstanceMethods)
Hope that helps!