I am writing a program to better learn to program and I wish to use RSpec so that I can learn that as well. However, as is, the code isn't particularly RSpec friendly, so I need to break it up into methods so that I can test it.
I don't need anyone to write the code for me, but perhaps explain how I can break it up. I am new to programming and this kind of thing (breaking things up into methods) is a really difficult concept for me.
Here's what I have:
if params[:url] != ''
url = params[:url] #line created so I can return url more easily (or, in general)
words = params[:word].gsub("\n", ",").delete("\r").split(",") #.delete redundant?
words.reject!(&:empty?)
words.each(&:lstrip!)
return "#{words}", "#{url}" #so that I can return url, not sure how to do that yet
end
The code is a SERP checker, it takes a url and keywords and checks their location in the search engines.
For url, it'll just be the url of the website the user wishes to check... for word, it would be the keywords they wish to check their site against in Google.. a user may fill out the input form like so:
Corn on the cob,
Fibonacci,
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Your code takes a sloppy string and turns it into a clean array. You first clean up the string, then you polish the array. You could define methods for these actions.
def clean_up_words(str)
#code to clean str
str
end
def clean_up_list(arr)
#code to clean arr
arr
end
dirty_list = clean_up_words( params[:word]).split(',')
clean_list = clean_up_list( dirty_list )
def foo params
url = params[:url]
url.empty? ? nil : [params[:word].scan(/[^\s\r,]+/), url]
end
You are assigning url = params[:url]. If you are going to do that, you should do it before other places where you refer to the same thing to reduce the amount of calling [] on param.
You have several conditions on the words to be extracted. (a) Either split by "\n", ",", "\r", (b) the word should not be of 0 length, (c) white characters should be stripped off. All of this can be put together as scan(/[^\s\r,]+/).
You want to return two variables when url is not empty. Use an array in that case.
Related
I have in the html the location variable sometimes is used with a class called "result-hood" sometimes is used with another class called "nearby"
location = result.search('span.result-hood').text[2..-2]
location2 = result.search('span.nearby').text[2..-2]
so if one of the above classes is not used the result is nill, my question is how to get always the one that is not nill, I was thinking about the ternary operator "?" , but don't know how to use it.
Thanks,
You want the || ("or") operator:
location || location2
It returns the left side if that is not nil or false, and otherwise it returns the right side.
CSS supports logical or operations using a comma as the delimiter, so your selector can just be:
location = result.search('span.result-hood,span.nearby').text[2..-2]
XPath also supports logical or operator itself, the equivalent XPath would look like
location = result.search('//span[#class="result-hood"]|//span[#class="nearby"]').text[2..-2]
Ternary operator in ruby:
loc = location.nil? ? location2 : location
Hope this works.
Since you're looking for one or the other you can reduce this code to:
location = result.search('span.result-hood').text[2..-2]
|| result.search('span.nearby').text[2..-2]
Where that search operation could be fairly expensive, so why run it twice when you might need to run it only once. Now that you've minimized it like this you can take it a step further:
location = %w[ span.result-hood span.nearby ].map do |selector|
result.search(selector).text[2..-2]
end.compact.first
This looks a little complicated but what it does is convert each selector into the text extracted from result.search(...).text[2..-2] and then take the first non-nil value.
That technically computes all possible bits of text before extracting, so you can make it "lazy" and evaluate each one in sequence instead, stopping at the first match:
location = %w[ span.result-hood span.nearby ].lazy.map do |selector|
result.search(selector).text[2..-2]
end.select(&:itself).first
The nice thing about this approach is you can clean it up a little by declaring a constant in advance:
LOCATIONS = %w[ span.result-hood span.nearby ]
Then later you have more minimal code like this that will automatically accommodate any changes made to that array both in terms of precedence and addition of others:
location = LOCATIONS.lazy.map do |selector|
result.search(selector).text[2..-2]
end.select(&:itself).first
Since one can do:
a += 1
I was thinking whether one can also do something similar to:
a .= 1
The use case would be, for example, with ActiveRecord:
query = Model
query .= where(name: 'John') # instead of query = query.where(name: 'John')
Is this possible somehow?
Nope, ruby does not have anything like this. Only certain "compound operators" are allowed by Ruby syntax and this operator is not among them.
However, there might be workarounds under specific circumstances (not this one, though). If, say, you had an array, then instead of
ary = ary.select { ... } if foo
ary = ary.select { ... } if bar
ary = ary.compact
you'd be able to do
ary.select! { ... } if foo
ary.select! { ... } if bar
ary.compact!
(this can have unintended consequences, yes, because in-place mutation is dangerous in general. But in some cases it is desirable. Don't do it to shorten your code.)
Ruby is able to detect line continuations automatically:
query = Model
.where(name: 'John')
.select(:first_name)
This is equivalent to this (with the dots at the end):
query = Model.
where(name: 'John').
select(:first_name)
Note that due to the way lines are evaluated in IRB, only the second syntax (with the dots at the end of the line) works as intended there. With the first example, IRB would evaluate the line as soon as it sees the newline. In a Ruby script, both options work quite well.
There apply different style considerations here, with people having different opinions on which one is best.
Generally, this approach requires that the combined line is syntactically equivalent to a single line. You can't use inline conditions that way. This would thus be invalid syntax:
query = Model
.where(name: 'John') if some_condition
.select(:first_name)
If you require these conditions, it is just fine to assign intermediate results to a local variable as shown by Sergio Tulentsev in his answer. You'll often see this and it is not a code smell at all.
So, What I'm trying to do is make calls to a Reporting API to filter by all possible breakdowns (breakdown the reports by site, avertiser, ad type, campaign, etc...). But, one issue is that the breakdowns can be unique to each login.
Example:
user1: alice123's reporting breakdowns are ["site","advertiser","ad_type","campaign","line_items"]
user2: bob789's reporting breakdowns are ["campaign","position","line_items"]
When I first built the code for this reporting API, I only had one login to test with, so I hard coded the loops for the dimensions (["site","advertiser","ad_type","campaign","line_items"]). So what I did was pinged the API for a report by sites. Then for each site, pinged for advertisers, and each advertiser, I pinged for the next dimension and so on..., leaving me with a nested loop of ~6 layers.
basically what I'm doing:
sites = mechanize.get "#{base_ur}/report?dim=sites"
sites = Yajl::Parser.parse(sites.body) # json parser
sites.each do |site|
advertisers = mechanize.get "#{base_ur}/report?site=#{site.fetch("id")}&dim=advertiser"
advertisers = Yajl::Parser.parse(advertisers.body) # json parser
advertisers.each do |advertiser|
ad_types = mechanize.get "#{base_ur}/report?site=#{site.fetch("id")}&advertiser=#{advertiser.fetch("id")}&dim=ad_type"
ad_types = Yajl::Parser.parse(ad_types.body) # json parser
ad_types.each do |ad_type|
...and so on...
end
end
end
GET <api_url>/?dim=<dimension to breakdown>&site=<filter by site id>&advertiser=<filter by advertiser id>...etc...
At the end of the nested loop, I'm left with a report that's broken down as much granularity as possible.
This works now since I only thought that there was one path of breaking down, but apparently each account could have different dimensions breakdowns.
So what I'm asking is if given an array of breakdowns, how can I set up a nested loop to traverse down dynamically do the granularity singularity?
Thanks.
I'm not sure what your JSON/GET returns exactly but for a problem like this you would need recursion.
Something like this perhaps? It's not very elegant and can definitely be optimised further but should hopefully give you an idea.
some_hash = {:id=>"site-id", :body=>{:id=>"advertiser-id", :body=>{:id=>"ad_type-id", :body=>{:id=>"something-id"}}}}
#breakdowns = ["site", "advertiser", "ad_type", "something"]
def recursive(some_hash, str = nil, i = 0)
if #breakdowns[i+1].nil?
str += "#{#breakdowns[i]}=#{some_hash[:id]}"
else
str += "#{#breakdowns[i]}=#{some_hash[:id]}&dim=#{#breakdowns[i + 1]}"
end
p str
some_hash[:body].is_a?(Hash) ? recursive(some_hash[:body], str.gsub(/dim.*/, ''), i + 1) : return
end
recursive(some_hash, 'base-url/report?')
=> "base-url/report?site=site-id&dim=advertiser"
=> "base-url/report?site=site-id&advertiser=advertiser-id&dim=ad_type"
=> "base-url/report?site=site-id&advertiser=advertiser-id&ad_type=ad_type-id&dim=something"
=> "base-url/report?site=site-id&advertiser=advertiser-id&ad_type=ad_type-id&something=something-id"
If you are just looking to map your data, you can recursively map to a hash as another user pointed out. If you are actually looking to do something with this data while within the loop and want to dynamically recreate the loop structure you listed in your question (though I would advise coming up with a different solution), you can use metaprogramming as follows:
require 'active_support/inflector'
# Assume we are given an input of breakdowns
# I put 'testarr' in place of the operations you perform on each local variable
# for brevity and so you can see that the code works.
# You will have to modify to suit your needs
result = []
testarr = [1,2,3]
b = binding
breakdowns.each do |breakdown|
snippet = <<-END
eval("#{breakdown.pluralize} = testarr", b)
eval("#{breakdown.pluralize}", b).each do |#{breakdown}|
END
result << snippet
end
result << "end\n"*breakdowns.length
eval(result.join)
Note: This method is probably frowned upon, and as I've said I'm sure there are other methods of accomplishing what you are trying to do.
I'm trying to display total calls from a twilio object as well as unique calls.
The total calls is simple enough:
# set up a client to talk to the Twilio REST API
#sub_account_client = Twilio::REST::Client.new(#account_sid, #auth_token)
#subaccount = #sub_account_client.account
#calls = #subaccount.calls
#total_calls = #calls.list.count
However, I'm really struggling to figure out how to display unique calls (people sometimes call back form the same number and I only want to count calls from the same number once). I'm thinking this is a pretty simple method or two but I've burnt quite a few hours trying to figure it out (still a ruby noob).
Currently I've been working it in the console as follows:
#sub_account_client = Twilio::REST::Client.new(#account_sid, #auth_token)
#subaccount = #sub_account_client.account
#subaccount.calls.list({})each do |call|
#"from" returns the phone number that called
print call.from
end
This returns the following strings:
+13304833615+13304833615+13304833615+13304833615+13304567890+13304833615+13304833615+13304833615
There are only two unique numbers there so I'd like to be able to return '2' for this.
Calling class on that output shows strings. I've used "insert" to add a space then have done a split(" ") to turn them into arrays but the output is the following:
[+13304833615][+13304833615][+13304833615][+13304833615][+13304567890][+13304833615][+13304833615][+13304833615]
I can't call 'uniq' on that and I've tried to 'flatten' as well.
Please enlighten me! Thanks!
If what you have is a string that you want to manipulate the below works:
%{+13304833615+13304833615+13304833615+13304833615+13304567890+13304833615+13304833615+13304833615}.split("+").uniq.reject { |x| x.empty? }.count
=> 2
However this is more ideal:
#subaccount.calls.list({}).map(&:from).uniq.count
Can you build an array directly instead of converting it into a string first? Try something like this perhaps?
#calllist = []
#subaccount.calls.list({})each do |call|
#"from" returns the phone number that called
#calllist.push call.from
end
you should then be able to call uniq on #calllist to shorten it to the unique members.
Edit: What type of object is #subaccount.calls.list anyway?
uniq should work for creating a unique list of strings. I think you may be getting confused by other non-related things. You don't want .split, that's for turning a single string into an array of word strings (default splits by spaces). Which has turned each single number string, into an array containing only that number. You may also have been confused by performing your each call in the irb console, which will return the full array iterated on, even if your inner loop did the right thing. Try the following:
unique_numbers = #subaccount.calls.list({}).map {|call| call.from }.uniq
puts unique_numbers.inspect
For a project that I am working on for school, one of the parts of the project asks us to take a collection of all the Federalist papers and run it through a program that essentially splits up the text and writes new files (per different Federalist paper).
The logic I decided to go with is to run a search, and every time the search is positive for "Federalist No." it would save into a new file everything until the next "Federalist No".
This is the algorithm that I have so far:
file_name = "Federalist"
section_number = "1"
new_text = File.open(file_name + section_number, 'w')
i = 0
n= 1
while i < l.length
if (l[i]!= "federalist") and (l[i+1]!= "No")
new_text.puts l[i]
i = i + i
else
new_text.close
section_number = (section_number.to_i +1).to_s
new_text = File.open(file_name + section_number, "w")
new_text.puts(l[i])
new_text.puts(l[i+1])
i=i+2
end
end
After debugging the code as much as I could (I am a beginner at Ruby), the problem that I run into now is that because the while function always holds true, it never proceeds to the else command.
In terms of going about this in a different way, my TA suggested the following:
Put the entire text in one string by looping through the array(l) and adding each line to the one big string each time.
Split the string using the split method and the key word "FEDERALIST No." This will create an array with each element being one section of the text:
arrayName = bigString.split("FEDERALIST No.")
You can then loop through this new array to create files for each element using a similar method you use in your program.
But as simple as it may sound, I'm having an extremely difficult time putting even that code together.
i = i + i
i starts at 0, and 0 gets added to it, which gives 0, which will always be less than l, whatever that value is/means.
Since this is a school assignment, I hesitate to give you a straight-up answer. That's really not what SO is for, and I'm glad that you haven't solicited a full solution either.
So I'll direct you to some useful methods in Ruby instead that could help.
In Array: .join, .each or .map
In String: .split
Fyi, your TA's suggestion is far simpler than the algorithm you've decided to embark on... although technically, it is not wrong. Merely more complex.