in an attempt to create a model with an array as an atribute, i ended up creating an array of hashes like so:
data1 = {}
data1[:name] = "Virtual Memory"
data1[:data] = #jobs.total_virtual_memory
data2 = {}
data2[:name] = "Memory"
data2[:data] = #jobs.total_memory
#data = []
#data << data1
#data << data2
which populates #data like this:
[{:data=>[#<Job day: "2010-08-02">, #<Job day: "2010-08-04">], :name=>"Virtual Memory"}, {:data=>[#<Job day: "2010-08-02">, #<Job day: "2010-08-04">], :name=>"Memory"}]
However i do not know how to acces these variables in the view. So as tu run somethig like:
for series in #data
series:name
for d in series:data
data:[Date, Value]
end
end
which would return something along the lines of:
Name1
Date1, Value1
Date2, Value 2,
Date3, Value 3,
Date4, Value 4,
Name2
Date1, Value 1,
Date2, Value 2,
Date3, Value 3,
Date4, Value 4,
This should work:
<% for series in #data %>
<%= series[:name] %>
<% for d in series[:data] %>
<%= d.date %>, <%= d.value %>
<% end %>
<% end %>
However you might consider using a more suitable datastructure instead of hashs. A Struct for example. This could look like this:
# in lib/JobData.rb:
JobData = Struct.new(:name, :data)
# in the controller:
data1 = JobData.new("Virtual Memory", #jobs.total_virtual_memory)
data2 = JobData.new("Memory", #jobs.total_memory)
#data = [data1, data2]
# in the view:
<% for series in #data %>
<%= series.name %>
<% for d in series.data %>
<%= d.date %>, <%= d.value %>
<% end %>
<% end %>
As a style point: I used for because you used for, but in general it's considered more rubyish to use each instead.
Here is the view:
<% for d in #data %>
{ pointInterval: <%= 1.day * 1000 %>,
name:<%= "'#{d[:name]}'"%>,
pointStart: <%= 2.weeks.ago.at_midnight.to_i * 1000 %>,
data: [
<% for chart in d[:data] %>
<%= "'[#{chart.day.to_time(:utc).to_i * 1000}, #{chart.data_attribute}],'" %>
<% end %>
]
},
<% end %>
Use #{d[:name]} to access the value of the "name" key and use d[:data] to access the array, then just loop throughthe array as if it were any normal array
Related
I have an array of objects, where I have the following fields: title, name e url
My data:
#array = [
{ id: 1, title: '123', name: 123 },
{ id: 2, title: '123', name: 321 },
{ id: 3, title: '1234', name: 123 },
]
I need to group my data by title and then make the map with the names
<%= #array.map do |x| %>
<div class='col-md-12'>
<h3><%= x.title %></h3>
<div class="row">
<%= #array.filter do |y| %>
<div class="col-4">
<% if y.title === x.title %>
<p><%= t.name %></p>
<% end %>
</div>
<% end.join.html_safe %>
</div>
</div>
<% end.join.html_safe %>
The return is:
title = '123'
name = '123'
name = '321'
title = '123'
name = '123'
name = '321'
title = '123'
name = '123'
That is, my array comes duplicated ... how to proceed?
Remembering that I am inside the rails view
You're getting duplicate entries since you're mapping over all the elements and filtering the array for every element inside the block.
You can use Enumerable#group_by to group the array elements by title. You can then iterate over the groups and display the title and names of each group. Note that I'm using item[:name] to access the values from the hash since your question mentions an array of hashes. You should update it to item.name (and other places using hash access) if you're working with objects instead.
#groups = #array.group_by {|i| i[:title] }
<% #groups.each do |title, items| %>
<h3><%= title %></h3>
<% items.each do |item| %>
<p><%= item[:name] %></p>
<% end %>
<% end %>
I'm trying to subtract the current item in the loop with the next indexed item, but I'm just getting the following error: undefined method `[]' for 0.0:Float
<% #trial.methods.each_with_index do |e, index| %>
<%= (e.total - e.total[index+1]) %><br />
<%= Time.at(e.try(:assessment).try(:assessment_date)/1000).strftime("%d/%m/%Y") %><br />
<%= e.try(:assessment).try(:degrees) %>
<% end %>
I think there is an easier way of doing that. Look at the following example.
# An array of 5 random numbers
a = [7,12,1,2,3]
# Iterate through the indices of the array
a.each_index do |i|
# We only show the result of a[i+1] - a[i]
# given i+1 is still in range of the array
puts "#{a[i+1] - a[i]}" if (i+1) < a.length
end
This should output 5 -11 1 1 each on a new line.
Similarly, you could do something like this:
<% #trial.methods.each_index do |i| %>
<% if i + 1 < e.total.length %>
<%= (e.total[i] - e.total[index+1]) %>
<% else %>
<%= 0 %>
<% end %>
<% end %>
Use #each_cons to build a subarray of consecutive pairs, then map it:
array = [7,12,1,2,3]
array.each_cons(2).map{ |e| e.last - e.first }
# => [5, -11, 1, 1]
A slight alternative:
array.each_cons(2).map{ |a, b| b - a }
Of course, you can change to a - b or whatever you need.
The first part does this:
array.each_cons(2).each {|e| p e}
# => [7, 12]
# => [12, 1]
# => [1, 2]
# => [2, 3]
You can use Enumerable#reduce to achieve this:
a = [7,12,1,2,3]
a.reduce(&:-) # -11
So for your case:
#trial.methods.map{|e| e.total}.reduce(&:-)
See https://ruby-doc.org/core-2.2.3/Enumerable.html#method-i-reduce on its usage
I got this very confusing array of hashes as an API response.
http://jsfiddle.net/PP9N5/
( the full response is massive. Posting only a part of it but it covers all elements of the response)
How can I get to "airlines".
I tried this
<% #flight["air_search_result"]["onward_solutions"]["solution"].each do|h| %>
<strong><%=h["pricing_summary"]["total_fare"] %></strong> -
<% h["flights"]["flight"]["segments"]["segment"].each do |s| %>
<%= s['airline'] %>
<% end %> <br> <hr>
<% end %>
And I get this error
can't convert String into Integer
I did some modifications like
<%= h["flights"]["flight"]["segments"]["segment"].first["airline"] %>
Error received - can't convert String into Integer
and
<%= h["flights"]["flight"]["segments"]["segment"][0]["airline"] %>
Error received - undefined method '[]' for nil:NilClass
Isnt there a simple way, like I say to find a key "airline" and for that key it returns its value. I stumbled upon this link, though I dont get any error, I also dont get any result.
Thanks.
UPDATE
I did this
<% h["flights"]["flight"]["segments"]["segment"].each do |o,p| %>
<% if o=="airline" %> <%= p %> <% end %>
<% end %> <br> <hr>
<% end %>
I can get few values of airlines where inside segment there is no array.
For eg, i can get where departure_date_time is 2014-07-07T07:10:00, index = 5.
http://jsfiddle.net/PP9N5/1/ (scroll down)
Here is some code you can add which will extract all keys equal the parameter in any Hash within your Hash:
class Hash
def deep_find(query, &block)
flat_map do |key, value|
if key == query
yield value if block_given?
[value]
elsif value.is_a? Hash
value.deep_find(query, &block)
elsif value.is_a? Array
value.select { |i| i.is_a? Hash }.flat_map { |h| h.deep_find(query, &block) }
end
end
end
end
Example:
hash = {"h" => [{ 'x' => [1, 5] }, { 'x' => 2 }, { 'f' => { 'x' => [3, 4] } }], 'x' => 6 }
hash.deep_find('x') { |x| puts "#{x}" }
# [1, 5]
# 2
# [3, 4]
# 6
# => [[1, 5], 2, [3, 4], 6]
it's a tipical problem :D
Replace "=>" for ":" and render.
your_json = {.....}
your_json.gsub("=>", ":")
puts your_json
You can validate a JSON before to work it with http://jsonlint.com/.
I have an array [["Company Name", "Field6"], ["Email", "Field5"]]
And from that array I am creating array of fields with values:
[
[{:label=>"Company Name", :value=>"gfdgfd"}],
[{:label=>"Email", :value=>"gfdgfd#gfd.pl"}]
]
using
fields = [["Company Name", "Field6"], ["Email", "Field5"]]
# first element in array is Label and second is param id
fields_with_values = fields.collect do |field|
[
label: field[0],
value: params[field[1]]
]
end
and then I want to pass that labels and values to erb template(something like):
# template.erb
<% fields_with_values.each do |field| %>
l: <%= field.label %>
v: <%= field.value %>
<% end %>
How will be the best way to collect these fields_with_values ? Maybe I should use Object.new
Convert to a hash instead.
fields = [["Company Name", "Field6"], ["Email", "Field5"]]
fields_with_values = Hash[*fields.flatten]
# => {"Company Name"=>"Field6", "Email"=>"Field5"}
In your view, parse the hash:
<% fields_with_values.each do |label, value| %>
l: <%= label %>
v: <%= params[value.intern] %>
<% end %>
Note that this will break if your input array is uneven, ie. a key without a value.
EDIT
As mentioned in a comment below (+1), duplicate keys will not work. Fields that have the same label as another field are no good.
fields = [["Company Name", "Field6"], ["Email", "Field5"]]
# first element in array is Label and second is param id
fields_with_values = fields.collect do |label, param_id|
# It looks like there is no need for a nested array here, so just return a Hash
{
label: label,
value: params[param_id]
}
end
#=> [{:label=>"Company Name", :value=>"gfdgfd"}, {:label=>"Email", :value=>"gfdgfd#gfd.pl"}]
It looks like you are trying to use dot syntax to get values out of a Ruby Hash similar to how you would use dot syntax for a JavaScript object (e.g. field.label). Unfortunately this doesn't work for Ruby. I wish it did because it looks very clean. For the Ruby Hash you must use an index, which is a symbol in this case: field[:label]. Your ERB code will look something like this:
# template.erb
<% fields_with_values.each do |field| %>
l: <%= field[:label] %>
v: <%= field[:value] %>
<% end %>
The easy most basic way would be:
class Foo
attr_accessors :label, :value
def initialize (label, value)
#label = label
#value = value
end
end
fields_with_values = fields.map do |field|
Foo.new(field[0], params[field[1]])
end
from here on you can make it more Ruby way with splat operator or create the objects on the fly, etc. etc.
l:
v:
I would do
fields_with_values = fields.collect do |field|
{label: field[0], value: params[field[1]}
end
And in the view
<% fields_with_values.each do |field| %>
l: <%= field[:label] %>
v: <%= field[:value] %>
<% end %>
However, lets say label is a company and value is an e-mail. If you have a class like
class Company < SomethingOrNothing
attr_accessible :name, email
# methods here
end
You could do
#companies = fields.collect do |field|
Company.new(name: field[0], email: field[1])
end
And then
<% #companies.each do |company| %>
l: <%= comapny.name %>
v: <%= company.email %>
<% end %>
However, most likely creating a new class just for that is over engineering, unless you will use this class over and over in your code.
I have an array:
<% #widgets.each do |w| %>
...
<% end %>
How can I display them in groups? Let's say by 4:
<div>1, 2, 3, 4</div>
<div>5, 6, 7, 8</div>
etc.
Thank you.
For the specific example you gave, you want each_slice:
<% #widgets.each_slice(4) do |ws| %>
<div><%= ws.join(', ') %></div>
<% end %>
You might also be interested in each_cons (each consecutive, e.g. "1,2,3", "2,3,4", "3,4,5", etc.) or group_by for arbitrary groupings.
Person = Struct.new(:name,:age,:male) do
def inspect
"<#{'fe' unless male}male '#{name}' #{age}>"
end
end
all = [
Person.new("Diane", 12, false),
Person.new("Harold", 28, true),
Person.new("Gavin", 38, true),
Person.new("Judy", 55, false),
Person.new("Dirk", 59, true)
]
p all.group_by(&:male)
#=> {
#=> false=>[ <female 'Diane' 12>, <female 'Judy' 55> ],
#=> true =>[ <male 'Gavin' 38>, <male 'Harold' 28>, <male 'Dirk' 59> ]
#=> }
p all.group_by{ |person| (person.age / 10) * 10 }
#=> {10=>[<female 'Diane' 12>],
#=> 20=>[<male 'Harold' 28>],
#=> 30=>[<male 'Gavin' 38>],
#=> 50=>[<female 'Judy' 55>, <male 'Dirk' 59>]}
Try to use each_slice(n):
require 'erb'
#widgets = (1..8).to_a
template = <<EOF
<% #widgets.each_slice(4) do |w| %>
<div><%= w.join(', ') %></div>
<% end %>
EOF
puts ERB.new(template).result(binding)
# =>
<div>1, 2, 3, 4</div>
<div>5, 6, 7, 8</div>