passing value (through variable) to custom function - ruby

I'm trying this thing for a while but can't figure out what am I doing wrong.
Here is sample function (which is similar to the original one, except for the hash, which is generated dynamically in the original one):
module Puppet::Parser::Functions
newfunction(:am_running_oss, :type => :rvalue ) do |args|
oss = {:linux=>["Slackware", "RedHat", "Caldera"],
:mac=>["Jaguar", "Lion", "Tiger", "Kodiak"],
:win=>["Chicago", "Daytona", "Longhorn"]}
cls = args[0]
if oss.key?(cls)
return oss[cls][0]
else
return 'undefined'
end
end
end
and then in my manifest, I have this:
$h= am_running_oss($::am_os_type)
notify { "=*=*= amRunningOS <|:|> ${h} =*=*=*=*=*=*=*=": }
(am_os_type is a fact, that returns win, mac or linux based on the node type)
I was expecting to see Jaguar or Slackware as the return value but I get undefined instead. Does anyone know what am I doing wrong? Is there anything still am I missing in terms of passing the args to the function? Cheers!!

Replying to my own question, in case google lands someone here looking for the same. The thing worked for me is to is define cls like this:
cls = args[0].to_sym if args[0].is_a? String
Cheers!!

Related

How to make Ruby Mocha mock only check about one parameter

I want to mock this function:
def self.set_segment_info(segment_info, history_record)
history_record.segment_info = segment_info
end
In my test, I want a mock that only confirms that I called set_segment_info with an expected value. I don't care about what I pass in for history_record.
How would I do this? I tried
SegmentHistoryRecord.expects(:set_segment_info).with(:segment_info => expected_segment_info, :history_record => anything)
But that doesn't work.
I ran into this today and ended up doing something like:
SegmentHistoryRecord.expects(:set_segment_info).with(
expected_segment_info,
anything
)
I find it more readable that the do version and it helped me avoid a rubocop issue with too many parameters.
Here's an implementation where, if your function takes a lot of parameters, it's more convenient to specify a value for just the one you care about, instead of for all of them:
expected_segment_info = # ...
SegmentHistoryRecord.expects(:set_segment_info).with() { |actual_parameters| actual_parameters[:segment_info] == expected_segment_info }
(Where, as in the original question, set_segment_info is the function being mocked, and segment_info is the parameter whose value you want to match. Note that the history_record parameter -- and any others that might be present -- don't need to be included.)
SegmentHistoryRecord.expects(:set_segment_info).with() do |param1, param2|
# change below to your verification for :segment_info
# and leave param2 doing nothing, the expectation will ignore param2
param1 == expected_segment_info
end

Get param value dynamically

My question model holds the prompt and the answer choices for questions that students can answer. It includes columns named :choice_0, :choice_1, :choice_2, :choice_3, :choice_4, and :choice_5.
In one section of my controller, I've used the following code:
correct_array.push(these_params[:choice_0]) if !these_params[:choice_0].blank?
correct_array.push(these_params[:choice_1]) if !these_params[:choice_1].blank?
correct_array.push(these_params[:choice_2]) if !these_params[:choice_2].blank?
correct_array.push(these_params[:choice_3]) if !these_params[:choice_3].blank?
correct_array.push(these_params[:choice_4]) if !these_params[:choice_4].blank?
correct_array.push(these_params[:choice_5]) if !these_params[:choice_5].blank?
In other areas of my app, I've used the #{} syntax, for example:
params[:choice_#{n}]
But that doesn't work within a params hash for some reason. I'm sure that there is a drier way to accomplish these five lines.
Thank you in advance for any insight.
A more Ruby way to do this is:
correct_array = (0..5).map { |i| these_params["choice_#{i}".to_sym] }.select(&:present?)
Or as a method:
def correct_array
(0..5).map { |i| these_params["choice_#{i}".to_sym] }.select(&:present?)
end
In either case, you have the added bonus of not having to initialize correct_array as it is created on the fly.
You may try this
(0..5).each do |i|
param_i = these_params["choice_#{i}".to_sym]
correct_array.push(param_i) if param_i.present?
end

How to use polymorphism to remove a switch statement which compares strings?

I am new to Ruby, so let me describe the context of my problem first:
I have a json as input which has the following key / value pair:
{
"service": "update"
}
The value has many different values for example: insert,delete etc.
Next there is a method x which handles the different requests:
def x(input)
case input[:service]
services = GenericService.new
when "update"
result = services.service(UpdateService.new,input)
when "insert"
result = services.service(InsertService.new,input)
when "delete"
result = services.service(DeleteService.new,input)
....
....
else
raise "Unknown service"
end
puts JSON.pretty_generate(result)
end
What is bothering me is that I still need to use a switch statement to check the String values (reminds me of 'instance of' ugh..). Is there a cleaner way (not need to use a switch)?
Finally I tried to search for an answer to my question and did not succeed, if however I missed it feel free to comment the related question.
Update: I was thinking to maybe cast the string to the related class name as follows: How do I create a class instance from a string name in ruby? and then call result = services.services(x.constantize.new,input) , then the class names ofcourse needs to match the input of the json.
You can try something like:
def x(input)
service_class_name = "#{input[:service].capitalize}Service"
service_class = Kernel.const_get(service_class_name)
service_class.new(input).process
end
In addition you might want to check if this is a valid Service class name at all.
I don't understand why you want to pass the service to GenericService this seems strange. let the service do it's job.
If you're trying to instatiate a class by it's name you're actually speaking about Reflection rather than Polymorphism.
In Ruby you can achieve this in this way:
byName = Object.const_get('YourClassName')
or if you are in a Rails app
byName= 'YourClassName'.constantize
Hope this helps
Just first thoughts, but you can do:
eval(services.service("#{input[:service].capitalize}Service.new, #{input})") if valid_service? input[:service]
def valid_service?
w%(delete update insert).include? input[:service]
end
As folks will no doubt shout, eval needs to be used with alot of care

pg gem: 'Warning: no type cast defined for type "numeric" '

I'm having trouble getting typed results out of the pg gem.
require 'pg'
require_relative 'spec/fixtures/database'
client = PG.connect( DB[:pg] )
client.type_map_for_queries = PG::BasicTypeMapForQueries.new(client)
client.type_map_for_results = PG::BasicTypeMapForResults.new(client)
client.exec( %|select * from testme;| ) do |query|
query.each {|r| puts r.inspect }
end
This program gives the output:
Warning: no type cast defined for type "money" with oid 790. Please cast this type explicitly to TEXT to be safe for future changes.
Warning: no type cast defined for type "numeric" with oid 1700. Please cast this type explicitly to TEXT to be safe for future changes.
{"string"=>"thing", "logical"=>true, "cash"=>"£1.23", "reel"=>"2.34", "day"=>#<Date: 2015-12-31 ((2457388j,0s,0n),+0s,2299161j)>, "float"=>3.45}
So: booleans and floats and dates (and integers) get converted, but not numerics or the money type.
Can anyone tell me how to "cast the type explicitly", assuming that I don't want to hard-code a solution for each table?
Hijacking this thread, as after some digging I finally found a way to add a custom decoder/encoder, so posting an example below:
require 'ipaddr'
require 'pg'
class InetDecoder < PG::SimpleDecoder
def decode(string, tuple=nil, field=nil)
IPAddr.new(string)
end
end
class InetEncoder < PG::SimpleEncoder
def encode(ip_addr)
ip_addr.to_s
end
end
# 0 if for text format, can also be 1 for binary
PG::BasicTypeRegistry.register_type(0, 'inet', InetEncoder, InetDecoder)
Here's a catch all for those seeking to cast strings by default:
client = PG.connect( DB[:pg] )
map = PG::BasicTypeMapForResults.new(conn)
map.default_type_map = PG::TypeMapAllStrings.new
client.type_map_for_results = map
Got the same problem with a text-ish field. Solved by duplicating a coder and editing its OID.
text_coder = client.type_map_for_results.coders.find { |c| c.name == 'text' }
new_coder = text_coder.dup.tap { |c| c.oid = 19 } # oid from the warning
conn.type_map_for_results.add_coder(new_coder)
How I got there: it might interest the next guy, if the problem is similar but not identical.
I read other people online talking about type_map_for_results, but how they didn't know how to define a coder. Since it was a text field in my case, I decided to try cloning an existing one. I knew I could find a textual pre-set in a Rails app, so I opened a rails console and searched:
adapter = ActiveRecord::Base.connection
connection = adapter.instance_variable_get("#connection")
mapping = connection.type_map_for_results
cd mapping # my console of choice is `pry`
ls # spotted a likely getter named `coders`
cd coders # again
ls # spotted getter `name` and setter `oid=`
So I put together the code in the solution. Gave it a try, and it worked.
It had not been straightforward to find, so I decided to exit lurker mode and share it on SO. Thereby: thanks #Andreyy for bringing me in :)
[pry cd and ls]
Google the error message: "Warning: no type cast defined for type"
You can find it's source github.
Reding the class, I would guess lines from 150 to 214 could be consiredered
examples:
register_type 0, 'text', PG::TextEncoder::String
alias_type 0, 'varchar', 'text'
Since register_type and alias_type are class methods of PG::BasicTypeRegistry::CoderMap I would play with them just and see if anything changes:
PG::BasicTypeRegistry::CoderMap.alias_type 0, 'money', 'text'
PG::BasicTypeRegistry::CoderMap.alias_type 0, 'numeric', 'text'
Reading the comments in the class it seems that the coding/decoding of those and some other fields is not implemented.
You might consider using a higher level ORM library like AvtiveRecord which implements more types (money).

Sinatra can't convert Symbol into Integer when making MongoDB query

This is a sort of followup to my other MongoDB question about the torrent indexer.
I'm making an open source torrent indexer (like a mini TPB, in essence), and offer both SQLite and MongoDB for backend, currently.
However, I'm having trouble with the MongoDB part of it. In Sinatra, I get when trying to upload a torrent, or search for one.
In uploading, one needs to tag the torrent — and it fails here. The code for adding tags is as follows:
def add_tag(tag)
if $sqlite
unless tag_exists? tag
$db.execute("insert into #{$tag_table} values ( ? )", tag)
end
id = $db.execute("select oid from #{$tag_table} where tag = ?", tag)
return id[0]
elsif $mongo
unless tag_exists? tag
$tag.insert({:tag => tag})
end
return $tag.find({:tag => tag})[:_id] #this is the line it presumably crashes on
end
end
It reaches line 105 (noted above), and then fails. What's going on? Also, as an FYI this might turn into a few other questions as solutions come in.
Thanks!
EDIT
So instead of returning the tag result with [:_id], I changed the block inside the elsif to:
id = $tag.find({:tag => tag})
puts id.inspect
return id
and still get an error. You can see a demo at http://torrent.hypeno.de and the source at http://github.com/tekknolagi/indexer/
Given that you are doing an insert(), the easiest way to get the id is:
id = $tag.insert({:tag => tag})
id will be a BSON::ObjectId, so you can use appropriate methods depending on the return value you want:
return id # BSON::ObjectId('5017cace1d5710170b000001')
return id.to_s # "5017cace1d5710170b000001"
In your original question you are trying to use the Collection.find() method. This returns a Mongo::Cursor, but you are trying to reference the cursor as a document. You need to iterate over the cursor using each or next, eg:
cursor = $tag.find_one({:tag => tag})
return cursor.next['_id'];
If you want a single document, you should be using Collection.find_one().
For example, you can find and return the _id using:
return $tag.find_one({:tag => tag})['_id']
I think the problem here is [:_id]. I dont know much about Mongo but `$tag.find({:tag => tag}) is probably retutning an array and passing a symbol to the [] array operator is not defined.

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