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Any tips to refactor this condition?
params = {:p1=>"foo", :p2=>true, :p3=>nil, :pN=>""}
if params[:p1].present? && params[:p2].present? && params[:pN].present?
# do something...
Something like this:
params.values_at(:p1, :p2, :pN).all?(&:present?)
if params.values_at(*%i[p1 p2 p3]).all?(&:present?)
values_at returns an Array of the values for each key you provide.
all? is true iff the predicate (present?) is true for every member of the enumerable. values_at will include nil for a missing key (rather than omit it), so you don't need to worry about the array collapsing down to only present values.
keys = [:p1, :p2, :pN]
puts "hi" if keys.all? { |k| params[k].present? }
This has the advantage of terminating the hash lookup as soon as params[k].present? is false.
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I am new to ruby and looking for a solution where I wanted to remove search a lines in a file with specific string and that string does not contains special characters.
eg:
irb(main):005:0> File.readlines("test.sh").select {|line| line =~ /Passphr|passphrs/}
=> ["passphrs=mw4test\n", "Passphrase=$passphrs\n", "Passphrase=$passphrs\n"]
I want ignore the text which is having "=$" as combination and desire output should be as:
passphrs=mw4test
Please suggest?
Perhaps just add a second condition to your select block:
File
.readlines("test.sh")
.select { |line| line =~ /Passphr|passphrs/ && !line.include?('=$') }
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Trying to add the contents of an array together.
["75.00", "50.00", "25.00"] the way I'm getting that info is with
c = Credit.last
c.payments.map(&:payment_amount).to_a
I'm trying to add up all the values together in the array.
The other posters are correct in that your question doesn't conform to the how to ask guidelines. The responses are not intended to put you down but rather to maintain the quality of content for stack overflow. That said this should get you where you need to go. IN the future please read the guidelines and submit accordingly.
Credit.last.payments.sum(:payment_amount.to_f)
One thing you may not have considered is that the array ["75.00", "50.00", "25.00"] contains a bunch of strings.
If you were to sum them together like this:
["75.00", "50.00", "25.00"].sum
# or like this as one commenter suggested
["75.00", "50.00", "25.00"].reduce(&:+)
# or the long-handed version
["75.00", "50.00", "25.00"].reduce {|str, val| str + val }
You would actually get "75.0050.0025.00". This is because the individual strings in the array are getting concatenated together.
So in fact, you would need to convert the array to floats or integers first. This can be done like this:
floats = ["75.00", "50.00", "25.00"].collect(&:to_f)
# or the long-handed version
["75.00", "50.00", "25.00"].collect {|val| val.to_f }
Then you can sum the values:
sum = floats.sum
Edit:
I just tried summing a string column via ActiveRecord and got an exception ActiveRecord::StatementInvalid: TinyTds::Error: Operand data type nvarchar is invalid for sum operator.:.
payment_total = Credit.last.payments.sum(:payment_amount)
# returns ActiveRecord::StatementInvalid:
# TinyTds::Error: Operand data type nvarchar is invalid for sum
# operator.
Looks like that won't be an option for you. Although, you could change the datatype of the column so that it is something other than a string. If you change the column datatype then you will be able to use aggregate functions.
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I am getting the following value in my params: "45,284"
How can I remove the the leading and trailing double quotes from my string?
The output that I should get is: 45,284
You can do this to your params[:userValues] to make it suitable for IN clause in your query
"45,284".split(",").map(&:to_i) #=> [45, 248]
So for params[:userValues] it will be
user_values = params[:userValues].split(",").map(&:to_i)
Now the query will look like this
#user = User.where('is_active = ? and is_support_user = ? and id IN (?)', true, false, user_values).order(:user_name)
This will work, try it out
class String
def trim
self.gsub!(/\A"|"\Z/, '')
end
end
"\"45,284\"".trim
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I've got a pretty standard Preferences table. I'd like to list all true booleans for each record therein. How would I go about that? I know that Preference.column_names will give me all, but I need each record's particular true settings. Any idea? Something like
#preference.column_names do |c|
c if c = true
end
Thanks!
Here's the general idea of looping through an objects attributes with the attribute name and value. Are you having to filter out only boolean fields? Or are all the fields boolean?
#preference.attributes.each do |attr_name, attr_value|
"#{attr_name} is #{attr_value}" if attr_value == true
end
First you'll need to know the boolean columns, something like this should give you their names:
booleans = Model.columns.select { |c| c.type == :boolean }.map(&:name)
Then you can use send to extract the values based on a name and a simple "is it true" test takes care of the rest:
trues = booleans.select { |name| #preference.send(name) == true }
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I have two questions.
1) I need to create a dynamic structure, whose members are driven through an array.
For ex:
members = [:a, :b]
Config = Struct.new(members) #=> Struct.new(:a, :b)
FlatConfig = Struct.new(members) #=> Struct.new(:a, :b)
config = Config.new()
flat = FlatConfig.new()
After some days, If I need to add another member to these struct, then all I need to do is add a member in that members array (memebers = [:a, :b, :c]) and I don't need to tough the code further. Thus I am asking this. How to achieve this?
2) Now I need to build the values of flat Struct members by means of doing some manipulation on config struct member values.
For eg:
config.each{|configMember|
result = configMember.collect{|c| someArray.collect{|s| s + '--' + y}}
flat[":#{cofigMember}"] = result #=> Intent is to store result in same member as iterated through config struct.
}
How to achieve (1) and (2)?
Thanks in advance.
For your 1), use the splat operator:
Struct.new(*members)
I don't really understand your second question. Is "how can I access the same variable in two configs"?
config.members.each { |key|
configMember = config[key]
# do something
flat[key] = result
}