I want to end up with an array of hashes.
I am starting with an array of codes:
#codes = ['123', '456', '789']
I take each of those codes and hit an API with them and it returns values that I parse into variables in a loop, like so:
#codes.each do |x|
#y = x.get_some_data
#brand = #y[brand]
#size = #y[size]
end
Then I want to put this data into an array of hashes
merged_array = []
final_hash = #codes.map{|code| {:code => code, :brand=> #brand, :size=> #size}
merged_array << final_hash
And in a perfect world, end up with hashes that look like this in the merged_array:
{:code => '123', :brand=> 'nike', :size=> 8 }
{:code => '456', :brand=> 'adidas', :size=> 4 }
{:code => '789', :brand=> 'converse', :size=> 10 }
But when I run my script it maps the codes right, but overwrites the #brand, #size variables and just returns the values of the last loop.
Not sure how to get all my variables into the hashes?
In your code example, the variables are all declared as being instance variables, because they're prefixed with #.
However, the variables within the loop are simply working/temporary variables, not instance variables. Additionally, x.get_some_data is probably not working, since x is just the loop variable and contains 456, abc, etc., and not an object with the desired method. Thus, the following code should produce your desired result:
def get_data(codes)
result = []
codes.each do |code|
y = get_some_data(code)
result << {
code: code,
brand: y['brand'],
size: y['size']
}
end
result
end
This is a very verbose example; you can put the whole logic in map, if the return value of get_some_data permits it.
A more elegant version would utilize Enumerable#each_with_object (the Array class includes Enumereable):
def get_data(codes)
codes.each_with_object([]) do |code, result|
y = get_some_data(code)
result << {
code: code,
brand: y['brand'],
size: y['size']
}
end
end
Thanks, Cary Swoveland, for pointing this out!
This should do the work
#codes.map{|code| {:code => code, :brand => code.get_some_data['brand'], code.get_some_data['size']}}
But, I'm really not sure what String.get_some_data will give you. Eg:- '123'.get_some_data['brand']
Related
I'm new in rails and need to clear one question:
for example my method return such data:
#<Article ART_ID: 1151754, ART_ARTICLE_NR: "0 281 002 757", ART_SUP_ID: 30, ART_DES_ID: nil, ART_COMPLETE_DES_ID: 62395, ART_CTM: nil, ART_PACK_SELFSERVICE: 0, ART_MATERIAL_MARK: 0, ART_REPLACEMENT: 0, ART_ACCESSORY: 0, ART_BATCH_SIZE1: nil, ART_BATCH_SIZE2: nil, datetime_of_update: "2012-09-25 17:49:18">
or array, not only one object: how could use each func then?
for example:
articles = ArtLookup.search_strong_any_kind_without_brand(params[:article_nr].gsub(/[^0-9A-Za-z]/, ''))
binding.pry
if articles.present?
articles.each do |a|
#all_parts_result <<
{
analogue_manufacturer_name: a.supplier.SUP_BRAND,
analogue_code: a.ART_ARTICLE_NR,
delivery_time_min: '',
delivery_time_max: '',
min_quantity: '',
product_name: a.art_name,
quantity: '',
price: '',
distributor_id: '',
link_to_tecdoc: a.ART_ID
}
end
end
now i get errors like
`undefined method `each' for `#<Article:0x007f6554701640>
i think it is becouse i have sometimes one object, sometimes 10, and sometime 0.
how is it beatifull and right to do in rails?
Your search_strong_any_kind_without_brand method is looping through your articles based on the search condition. If the article matches then you are setting #art_concret to the match and then returning the match. However, you're not finding all matches, just the last one.
.
loop
#art_concret = art
end
.
return #art_concret
If you set the #art_concret as an array and inject results into this instance variable, then you will have the resulting search in array form. However, keep in mind that this does kind of break the ActiveRecord ORM as you would be returning a simple array and not an ActiveRecord Relation array.
def self.search_strong_any_kind_without_brand(search)
search_condition = search.upcase
#art_concret = []
#search = find(:all, :conditions => ['MATCH (ARL_SEARCH_NUMBER) AGAINST(? IN BOOLEAN MODE)', search_condition])
#articles = Article.find(:all, :conditions => ["ART_ID in (?)", #search.map(&:ARL_ART_ID)])
#binding.pry
#articles.each do |art|
if art.ART_ARTICLE_NR.gsub(/[^0-9A-Za-z]/, '') == search
#art_concret << art
end
end
return #art_concret
end
If you want to keep the code a bit cleaner then use select on your matching condition instead of looping through each article in #articles.
def self.search_strong_any_kind_without_brand(search)
search_condition = search.upcase
#search = find(:all, :conditions => ['MATCH (ARL_SEARCH_NUMBER) AGAINST(? IN BOOLEAN MODE)', search_condition])
#articles = Article.find(:all, :conditions => ["ART_ID in (?)", #search.map(&:ARL_ART_ID)])
#binding.pry
return #articles.select { |art| art.ART_ARTICLE_NR.gsub(/[^0-9A-Za-z]/, '') == search }
end
Unrelated: is there a reason why you're using instance variables in search_strong_any_kind_without_brand?
I think the right thing to do is to make sure your method always returns an array (or enumerable).
looking at the code you posted in to pastebin I would recommend you use Array#select in your method
for example you might be able to just return this:
#articles.select { |art| art.ART_ARTICLE_NR.gsub(/[^0-9A-Za-z]/, '') == search }
assuming #articles is an array or collection you will always get an array back, even if it is 0, or 1 element
This answer would be a bit offtopic, but I would like to mention a splat operator:
[*val]
will produce array, consisting of either single val value whether it’s not an array, or the array itself whether val is an array:
▶ def array_or_single param
▷ [*param].reduce &:+ # HERE WE GO
▷ end
=> :array_or_single
▶ array_or_single [1,2,3]
=> 6
▶ array_or_single 5
=> 5
That said, you code would work with this tiny improvement:
- articles.each do |a|
+ [*articles].each do |a|
Hope it gives a hint on how one might handle the data, coming from the 3rd party. As an answer to your particular question, please follow the advises in the other answers here.
I have an array that contains dates and values. An example of how it might look:
[
{'1/1/2010' => 'aa'},
{'1/1/2010' => 'bb'},
{'1/2/2010' => 'cc'},
{'1/2/2010' => 'dd'},
{'1/3/2010' => 'ee'}
]
Notice that some of the dates repeat. I'm trying to output this in a table format and I only want to show unique dates. So I loop through it with the following code to get my desired output.
prev_date = nil
#reading_schedule.reading_plans.each do |plan|
use_date = nil
if plan.assigned_date != prev_date
use_date = plan.assigned_date
end
prev_date = plan.assigned_date
plan.assigned_date = use_date
end
The resulting table will then look something like this
1/1/2010 aa
bb
1/2/2010 cc
dd
1/3/2010 ee
This work fine but I am new to ruby and was wondering if there was a better way to do this.
Enumerable.group_by is a good starting point:
require 'pp'
asdf = [
{'1/1/2010' => 'aa'},
{'1/1/2010' => 'bb'},
{'1/2/2010' => 'cc'},
{'1/2/2010' => 'dd'},
{'1/3/2010' => 'ee'}
]
pp asdf.group_by { |n| n.keys.first }.map{ |a,b| { a => b.map { |c| c.to_a.last.last } } }
# >> [{"1/1/2010"=>["aa", "bb"]}, {"1/2/2010"=>["cc", "dd"]}, {"1/3/2010"=>["ee"]}]
Which should be a data structure you can bend to your will.
I don't know as though it's better, but you could group the values by date using (e.g.) Enumerable#reduce (requires Ruby >= 1.8.7; before that, you have Enumerable#inject).
arr.reduce({}) { |memo, obj|
obj.each_pair { |key, value|
memo[key] = [] if ! memo.has_key?(key);
memo[key] << value
}
memo
}.sort
=> [["1/1/2010", ["aa", "bb"]], ["1/2/2010", ["cc", "dd"]], ["1/3/2010", ["ee"]]]
You could also use Array#each to similar effect.
This is totally a job for a hash.
Create a hash and use the date as the hashkey and an empty array as the hashvalue.
Then accumulate the values from the original array in the hashvalue array
I am using ruby-aaws to return Amazon Products and I want to enter them into my DB. I have created a model Amazonproduct and I have created a method get_amazon_data to return an array with all the product information. When i define the specific element in the array ( e.g. to_a[0] ) and then use ruby-aaws item_attributes method, it returns the name I am searching for and saves it to my DB. I am trying to iterate through the array and still have the item_attributes method work. When i don't define the element, i get this error: undefined method `item_attributes' for #Array:0x7f012cae2d68
Here is the code in my controller.
def create
#arr = Amazonproduct.get_amazon_data( :r ).to_a
#arr.each { |name|
#amazonproduct = Amazonproduct.new(params[:amazonproducts])
#amazonproduct.name = #arr.item_attributes.title.to_s
}
EDIT: Code in my model to see if that helps:
class Amazonproduct < ActiveRecord::Base
def self.get_amazon_data(r)
resp = Amazon::AWS.item_search('GourmetFood', { 'Keywords' => 'Coffee Maker' })
items = resp.item_search_response.items.item
end
end
Thanks for any help/advice.
I'm not familiar with the Amazon API, but I do observe that #arr is an array. Arrays do not usually have methods like item_attributes, so you probably lost track of which object was which somewhere in the coding process. It happens ;)
Try moving that .item_attributes call onto the object that supports that method. Maybe amazonproduct.get_amazon_data(:r), before its being turned into an array with to_a, has that method?
It's not quite clear to me what your classes are doing but to use #each, you can do something like
hash = {}
[['name', 'Macbook'], ['price', 1000]].each do |sub_array|
hash[sub_array[0]] = sub_array[1]
end
which gives you a hash like
{ 'name' => 'Macbook', 'price' => 1000 }
This hash may be easier to work with
#product = Product.new
#product.name = hash[:name]
....
EDIT
Try
def create
#arr = Amazonproduct.get_amazon_data( :r ).to_a
#arr.each do |aws_object|
#amazonproduct = Amazonproduct.new(params[:amazonproducts])
#amazonproduct.name = aws_object.item_attributes.title.to_s
end
end
Lets say I have an Array of content_categories (content_categories = user.content_categories)
I now want to add every element belonging to a certain categorie to content_categories with the category as a key and the the content-item IDs as elements of a set
In PHP something like this is possible:
foreach ($content_categories as $key => $category) {
$contentsByCategoryIDArray = Category.getContents($category[id])
$content_categories[$key][$contentsByCategoryIDArray]
}
Is there an easy way in rails to do this?
Greets,
Nico
Your question isn't really a Rails question, it's a general Ruby programming question.
Your description isn't very clear, but from what I understand, you want to group IDs for common categories using a Hash. There are various other ways of doing this, but this is easy to understand::
ary = [
'cat1', {:id => 1},
'cat2', {:id => 2},
'cat1', {:id => 3}
]
hsh = {}
ary.each_slice(2) { |a|
key,category = a
hsh[key] ? hsh[key] << category[:id] : hsh[key] = [category[:id]]
}
hsh # => {"cat1"=>[1, 3], "cat2"=>[2]}
I'm using a simple Array with a category, followed by a simple hash representing some object instance, because it makes it easy to visualize. If you have a more complex object, replace the hash entries with those objects, and tweak how you access the ID in the ternary (?:) line.
Using Enumerable.inject():
hsh = ary.each_slice(2).inject({}) { |h,a|
key,category = a
h[key] ? h[key] << category[:id] : h[key] = [category[:id]]
h
}
hsh # => {"cat1"=>[1, 3], "cat2"=>[2]}
Enumerable.group_by() could probably shrink it even more, but my brain is fading.
I'd use Enumerable#inject
content_categories = content_categories_array.inject({}){ |memo, category| memo[category] = Category.get_contents(category); memo }
Hash[content_categories.map{|cat|
[cat, Category.get_contents(cat)]
}]
Not really the right answer, because you want IDs in your array, but I post it anyway, because it's nice and short, and you might actually get away with it:
content_categories.group_by(&:category)
content_categories.each do |k,v|
content_categories[k] = Category.getContents(v)
end
I suppose it's works
If i understand correctly, content_categories is an array of categories, which needs to be turned into a hash of categories, and their elements.
content_categories_array = content_categories
content_categories_hash = {}
content_categories_array.each do |category|
content_categories_hash[category] = Category.get_contents(category)
end
content_categories = content_categories_hash
That is the long version, which you can also write like
content_categories = {}.tap do |hash|
content_categories.each { |category| hash[category] = Category.get_contents(category) }
end
For this solution, content_categories must be a hash, not an array as you describe. Otherwise not sure where you're getting the key.
contents_by_categories = Hash[*content_categories.map{|k, v| [k, Category.getContents(v.id)]}]
I'm using the Google charts API to generate a pie chart in my Rails application. However, I'm having a problem passing local variables to the def in the helper. The def takes a 2D array of [label, value] pairs. It doesn't like it when I try to pass a local variable in as the value. These are calculated ahead of time and are in currency format. Putting the variable in quotes or in #{} doesn't work either.
application_helper.rb
def pie_chart(data, options = {})
options[:width] ||= 250
options[:height] ||= 100
options[:colors] = %w(F5DD7E 0DB2AC FC8D4D FC694D FABA32 704948 968144 C08FBC ADD97E)
dt = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-."
options[:divisor] ||= 1
options[:title] ||= "Energy Costs"
while (data.map { |k,v| v }.max / options[:divisor] >= 4096) do
options[:divisor] *= 20
end
opts = {
:cht => "p",
:chd => "e:#{data.map{|k,v|v=v/options[:divisor];dt[v/64..v/64]+dt[v%64..v%64]}}",
:chl => "#{data.map { |k,v| CGI::escape(k)}.join('|')}",
:chs => "#{options[:width]}x#{options[:height]}",
:chco => options[:colors].slice(0, data.length).join(','),
:chf => "bg,s,FFFFFF00",
:chtt => "#{options[:title]}"
}
The def call in the view:
<%= pie_chart( [["Light Cost", #{light_cost}], ["Small Appliance Cost", #{sm_appl_cost}]], :width => 550, :height => 200) %>
How do I pass the local variables?
What's the error you get? You should be able to call it like:
<%=
pie_chart(
[
["Light Cost", light_cost],
["Small Appliance Cost", sm_appl_cost]
],
{ :width => 550, :height => 200 }
)
%>
I added {}'s around the hash just to make it clearer and explicit.
Using #{var} is not the way to do it here because that's for substitution in a string, eg "Here is the value: #{var}".
So that code definitely wants numeric values, but #{} is just going to start a comment unless used inside a string, and you don't want a string there.
And actually, pie_chart as written would appear to take either a 2D array as you say OR a Hash, if the only use of it is with 2-variable .map iterators. So you should be able to use either [["str1", light_cost], ["str2", sm_appl_cost]] or { 'str1'=>light_cost, 'str2'=>sm_appl_cost}.
You do need to make sure that those locals are numeric, though. Try using .to_i or .to_f on them if they aren't.