I am new to Django but I have experience in Rails.
In Rails, if you want to check what one of your action/function is doing, you can use the raise parameter.
The execution of the action will stop, and in http://locahost:3000 you can see the output of that function.
Example:
def answer:
#banana = 2 + 2
raise
end
If I reload localhost, a console opens and if I write #banana I get the result 4.
Is there something similar in Django?
There's pdb. You can check more here. On your code, you can do something like this:
def answer():
banana = 2 + 2
import pdb; pdb.set_trace()
return banana
Then on your terminal if you do banana you'll see the result of the sum.
Related
I want to run my perticular scenario or feature file more than one time.
Let's say if user enter 5 then i want my url to be hit 5 times.
is it possible in karate? Any help would be appreciated
Yes, read the docs: https://github.com/intuit/karate#loops
But also see example below using dynamic scenario outlines:
EDIT: using a Background will not work in Karate 1.3.0 onwards, please refer to this example: https://stackoverflow.com/a/75155712/143475
Background:
* def fun = function(i){ return { name: 'User ' + (i + 1) } }
* def data = karate.repeat(5, fun)
Scenario Outline:
* url 'http://httpbin.org/anything'
* request __row
* method post
Examples:
| data |
So run this, see how it works and study how it works as well.
Note that data driven features is an alternate approach where you can call a second feature file in a loop. So for example after using karate.repeat() 5 times like in the above Background, you use data as the argument to a second feature file that hits your url.
class ScraperController < ApplicationController
def show
mechanize = Mechanize.new
website = mechanize.get('https://website.com/')
$max = 2
$counter = 0
$link_to_click = 2
#names = []
while $counter <= $max do
#names.push(website.css('.memName').text.strip)
website.link_with(:text => '2').text.strip.click
$link_to_click += 1
$counter += 1
end
end
end
I am trying to scrape 20 items off of each page and then click on the link at the bottom (1, 2, 3, 4, 5, etc.). However, I get the error as seen in the title which tells me that I cannot click the string. So it recognizes that the button '2' exists but will tell me if cannot click it. Ideally, once this is sorted out, I wanted to the use the $link_to_click variable as a way to replace the '2' so that it will increment each time but it always comes back as nil. I have also changed it to .to_s with the same result.
If I remove the click all together, it will scrape the same page 3 times instead of moving onto the next page. I have also removed the text.strip part before the .click and it will do the same thing. I have tried many variations but have had no luck.
I would really appreciate any advice you could offer.
I ended up reviewing the articles I was referencing to solve this and came to this conclusion.
I changed the website_link to website = website.link_with(:text => $link_to_click.to_s).click (because it only worked as a string) and it printed out the first page, second and each one thereafter.
These are the articles that I was referencing to learn how to do this.
http://docs.seattlerb.org/mechanize/GUIDE_rdoc.html
and
https://readysteadycode.com/howto-scrape-websites-with-ruby-and-mechanize
When a user uses my application, at one point they will get an array of arrays, that looks like this:
results = [["value",25], ["value2",30]...]
The sub arrays could be larger, and will be in a similar format. I want to allow my users to write their own custom transform function that will take an array of arrays, and return either an array of arrays, a string, or a number. A function should look like this:
def user_transform_function(array_of_arrays)
# eval users code, only let them touch the array of arrays
end
Is there a safe way to sandbox this function and eval so a user could not try and execute malicious code? For example, no web callouts, not database callouts, and so on.
First, if you will use eval, it will never be safe. You can at least have a look in the direction of taint method.
What I would recommend is creating your own DSL for that. There is a great framework in Ruby: http://treetop.rubyforge.org/index.html. Of course, it will require some effort from your side, but from the user prospective I think it could be even better.
WARNING: I can not guarantee that this is truly safe!
You might be able to run it as a separate process and use ruby $SAFE, however this does not guarantee that what you get is safe, but it makes it harder to mess things up.
What you then would do is something like this:
script = "arr.map{|e| e+2}" #from the user.
require "json"
array = [1, 2, 3, 4]
begin
results = IO.popen("ruby -e 'require \"json\"; $SAFE=3; arr = JSON.parse(ARGV[0]); puts (#{script}).to_json' #{array.to_json}") do |io|
io.read
end
rescue Exception => e
puts "Ohh, good Sir/Mam, your script caused an error."
end
if results.include?("Insecure operation")
puts "Ohh, good Sir/Mam, you cannot do such a thing"
else
begin
a = JSON.parse(results)
results = a
rescue Exception => e
puts "Ohh, good Sir/Mam, something is wrong with the results."
puts results
end
end
conquer_the_world(results) if results.is_a?(Array)
do_not_conquer_the_world(results) unless results.is_a?(Array)
OR
You could do this, it appears:
def evaluate_user_script(script)
Thread.start {
$SAFE = 4
eval(script)
}
end
But again: I do not know how to get the data out of there.
I am working on an app which has the below code:
def app
#app ||= begin
if !::File.exist? options[:config]
abort "configuration #{options[:config]} not found"
end
app, myoptions = Rack::Builder.parse_file(self.options[:config], opt_parser)
self.myoptions.merge! myoptions
app
end
end
I am struggling to get my head around several parts of it..
#app||= begin...end
Does this mean that if #app does not exist the block is run?
app ,options = rack::builder
What does the comma do to it?
Please help
Your first assumptions was correct, it does say that if #app is nil, set it to whatever is returned in the block delimited with begin, end.
Regarding the comma, it works like this:
avar, bvar = "atest", "btest"
If you look at the source for Rack:Builder.parse_file then you will notice the last line
return app, options
So it is returning two values.
Hope that helps
#Craig-Taub ansewered the question,
I just want to add some notes:
Ruby commands are expressions which means they return value and you can assign them to variables.
You can read more about expressions and statements on Wikipedia and PragProg.
Second is that when you return more than one value in a code block, Ruby will wrap it into a simple array and return it to the caller.
That's why it works like that.
I have a Rails app parsing incoming e-mails on Heroku using the Cloud-mailin add-on. The app recieves a list of prices in an e-mail and inserts them into the database.
This works fine, but if the e-mail contains for instance a signature in the bottom the code fails because it's also trying to parse that text.
Therefor I would like to rewrite the below parsing code to stop when it hits an empty line in the e-mail. All the price data is always at the top of the e-mail.
email_text = params[:plain]
email_text_array = []
email_text.split("\n").each do |email_line|
email_text_array << email_line.split(" ")
end
How do I change the above to stop when it hits an empty line in the email_taxt variable?
Thanks!
You can add a break :
email_text.split("\n").each do |email_line|
break if email_line.blank? # ends loop on first empty line
email_text_array << email_line.split(" ")
end
Does this question help: Is there a "do ... while" loop in Ruby?
Edit 1:
From the above article I think something like this would work:
email_text.split("\n").each do |email_line|
break if email_line.length < 1
email_text_array << email_line.split(" ")
end