parsing JSON into Ruby iterator - ruby

I have a JSON file with parsed data stored in a #colors instance variable, as follows:
[{:color=>"red", :value=>"#f00"} {:color=>"green", :value=>"#0f0"} {:color=>"blue", :value=>"#00f"} {:color=>"cyan", :value=>"#0ff"} {:color=>"magenta", :value=>"#f0f"} {:color=>"yellow", :value=>"#ff0"} {:color=>"black", :value=>"#000"}]
Now I want to iterate through this output to create a table in a view where there is
<tr><td>color</td><td>value</td></tr>
When I derive another instance variable like this --
#even_colors = #colors.values_at(* #colors.each_index.select {|i| i.even?}).map(&:values)
I get an array of arrays consisting of every other color/value pair
[["red", "#f00"], ["blue", "#00f"], ["magenta", "#f0f"], ["black", "#000"]]
But what I want to create two separate arrays, one consisting only of the color names indicated by :color (red, blue, etc.) and the other consisting of just the hexs indicated by :value (#f00, #00f, etc.). I can't seem to figure out how to do that. Anyone have any suggestions? Thanks ...

You could do it with two passes through #colors:
names = #colors.map { |h| h[:color] }
hexes = #colors.map { |h| h[:value] }
Or you could it with on pass:
parts = #colors.each_with_object({ :names => [ ], :hexes => [ ]}) do |h, parts|
parts[:names].push(h[:color])
parts[:hexes].push(h[:value])
end
then look at parts[:names] for the color names and parts[:hexes] for the hex values.
I don't really see why you want to split #colors up though, you could produce your table straight from#colors:
<table>
<% #colors.each do |h| %>
<tr><td><%= h[:color] %></td><td><%= h[:value] %></td></tr>
<% end %>
</table>
Breaking #colors into two arrays seems like busy-work to me.

Related

build a hash from iterating over a hash with nested arrays

I'd like to structure data I get pack from an Instagram API call:
{"attribution"=>nil,
"tags"=>["loudmouth"],
"location"=>{"latitude"=>40.7181015, "name"=>"Fontanas Bar", "longitude"=>-73.9922791, "id"=>31443955},
"comments"=>{"count"=>0, "data"=>[]},
"filter"=>"Normal",
"created_time"=>"1444181565",
"link"=>"https://instagram.com/p/8hJ-UwIDyC/",
"likes"=>{"count"=>0, "data"=>[]},
"images"=>
{"low_resolution"=>{"url"=>"https://scontent.cdninstagram.com/hphotos-xaf1/t51.2885-15/s320x320/e35/12145134_169501263391761_636095824_n.jpg", "width"=>320, "height"=>320},
"thumbnail"=>
{"url"=>"https://scontent.cdninstagram.com/hphotos-xfa1/t51.2885-15/s150x150/e35/c135.0.810.810/12093266_813307028768465_178038954_n.jpg", "width"=>150, "height"=>150},
"standard_resolution"=>
{"url"=>"https://scontent.cdninstagram.com/hphotos-xaf1/t51.2885-15/s640x640/sh0.08/e35/12145134_169501263391761_636095824_n.jpg", "width"=>640, "height"=>640}},
"users_in_photo"=>
[{"position"=>{"y"=>0.636888889, "x"=>0.398666667},
"user"=>
{"username"=>"ambersmelson",
"profile_picture"=>"http://photos-h.ak.instagram.com/hphotos-ak-xfa1/t51.2885-19/11909108_1492226137759631_1159527917_a.jpg",
"id"=>"194780705",
"full_name"=>""}}],
"caption"=>
{"created_time"=>"1444181565",
"text"=>"the INCOMPARABLE Amber Nelson closing us out! #loudmouth",
"from"=>
{"username"=>"alex3nglish",
"profile_picture"=>"http://photos-f.ak.instagram.com/hphotos-ak-xaf1/t51.2885-19/s150x150/11906214_483262888501413_294704768_a.jpg",
"id"=>"30822062",
"full_name"=>"Alex English"}}
I'd like to structure it in this way:
hash ={}
hash {"item1"=>
:location => {"latitude"=>40.7181015, "name"=>"Fontanas Bar", "longitude"=>-73.9922791, "id"=>31443955},
:created_time => "1444181565",
:images =>https://scontent.cdninstagram.com/hphotos-xaf1/t51.2885-15/s320x320/e35/12145134_169501263391761_636095824_n.jpg"
:user =>"Alex English"}
I'm iterating over 20 objects, each with their location, images, etc... how can I get a hash structure like the one above ?
This is what I've tried:
array_images = Array.new
# iterate through response object to extract what is needed
response.each do |item|
array_images << { :image => item.images.low_resolution.url,
:location => item.location,:created_time => Time.at(item.created_time.to_i), :user => item.user.full_name}
end
Which works fine. So what is the better way, the fastest one?
The hash that you gave is one item in the array stored at the key "data" in a larger hash right? At least that's how it is for the tags/ endpoint so I'll assume it's the same here. (I'm referring to that array of hashes as data)
hash = {}
data.each_with_index do |h, idx|
hash["item#{idx + 1}"] = {
location: h["location"], #This grabs the entire hash at "location" because you are wanting all of that data
created_time: h["created_time"],
image: h["images"]["low_resolution"]["url"], # You can replace this with whichever resolution.
caption: h["caption"]["from"]["full_name"]
}
end
I feel like you want a more simple solution, but I'm not sure how that's going to happen as you want things nested at different levels and you are pulling things from diverse levels of nesting.

How to convert partial XML to hash in Ruby

I have a string which has plain text and extra spaces and carriage returns then XML-like tags followed by XML tags:
String = "hi there.
<SET-TOPIC> INITIATE </SET-TOPIC>
<SETPROFILE>
<KEY>name</KEY>
<VALUE>Joe</VALUE>
</SETPROFILE>
<SETPROFILE>
<KEY>email</KEY>
<VALUE>Email#hi.com</VALUE>
</SETPROFILE>
<GET-RELATIONS>
<COLLECTION>goals</COLLECTION>
<VALUE>walk upstairs</VALUE>
</GET-RELATIONS>
So what do you think?
Is it true?
"
I want to parse this similar to use Nori or Nokogiri or Ox where they convert XML to a hash.
My goal is to be able to easily pull out the top level tags as keys and then know all the elements, something like:
Keys = ['SETPROFILE', 'SETPROFILE', 'SET-TOPIC', 'GET-OBJECT']
Values[0] = [{name => Joe}, {email => email#hi.com}]
Values[3] = [{collection => goals}, {value => walk up}]
I have seen several functions like that for true XML but all of mine are partial.
I started going down this line of thinking:
parsed = doc.search('*').each_with_object({}) do |n, h|
(h[n.name] ||= []) << n.text
end
I'd probably do something along these lines if I wanted the keys and values variables:
require 'nokogiri'
string = "hi there.
<SET-TOPIC> INITIATE </SET-TOPIC>
<SETPROFILE>
<KEY>name</KEY>
<VALUE>Joe</VALUE>
</SETPROFILE>
<SETPROFILE>
<KEY>email</KEY>
<VALUE>Email#hi.com</VALUE>
</SETPROFILE>
<GET-RELATIONS>
<COLLECTION>goals</COLLECTION>
<VALUE>walk upstairs</VALUE>
</GET-RELATIONS>
So what do you think?
Is it true?
"
doc = Nokogiri::XML('<root>' + string + '</root>', nil, nil, Nokogiri::XML::ParseOptions::NOBLANKS)
nodes = doc.root.children.reject { |n| n.is_a?(Nokogiri::XML::Text) }.map { |node|
[
node.name, node.children.map { |c|
[c.name, c.content]
}.to_h
]
}
nodes
# => [["SET-TOPIC", {"text"=>" INITIATE "}],
# ["SETPROFILE", {"KEY"=>"name", "VALUE"=>"Joe"}],
# ["SETPROFILE", {"KEY"=>"email", "VALUE"=>"Email#hi.com"}],
# ["GET-RELATIONS", {"COLLECTION"=>"goals", "VALUE"=>"walk upstairs"}]]
From nodes it's possible to grab the rest of the detail:
keys = nodes.map(&:first)
# => ["SET-TOPIC", "SETPROFILE", "SETPROFILE", "GET-RELATIONS"]
values = nodes.map(&:last)
# => [{"text"=>" INITIATE "},
# {"KEY"=>"name", "VALUE"=>"Joe"},
# {"KEY"=>"email", "VALUE"=>"Email#hi.com"},
# {"COLLECTION"=>"goals", "VALUE"=>"walk upstairs"}]
values[0] # => {"text"=>" INITIATE "}
If you'd rather, it's possible to pre-process the DOM and remove the top-level text:
doc.root.children.select { |n| n.is_a?(Nokogiri::XML::Text) }.map(&:remove)
doc.to_xml
# => "<root><SET-TOPIC> INITIATE </SET-TOPIC><SETPROFILE><KEY>name</KEY><VALUE>Joe</VALUE></SETPROFILE><SETPROFILE><KEY>email</KEY><VALUE>Email#hi.com</VALUE></SETPROFILE><GET-RELATIONS><COLLECTION>goals</COLLECTION><VALUE>walk upstairs</VALUE></GET-RELATIONS></root>\n"
That makes it easier to work with the XML.
Wrap the string content in a node and you can parse that with Nokogiri. The text outside the XML segment will be text node in the new node.
str = "hi there. .... Is it true?"
doc = Nokogiri::XML("<wrapper>#{str}</wrapper>")
segments = doc.xpath('/*/SETPROFILE')
Now you can use "Convert a Nokogiri document to a Ruby Hash" to convert the segments into a hash.
However, if the plain text contains some characters that needs to be escaped in the XML spec you'll need to find those and escape them yourself.

Watir method (or monkey-patch) to select span (or other) tags with custom ("data-*") attribute values equaling a string value (or matching a regex)

So this is ruby right, and while I do have a solution already, which I'll show below, its not tight. Feels like I'm using ahem "C++ iterators", if you will. Too many lines of code. Not like ruby.
Anyway, I'm wondering if there is classier way to do this:
b = Watir::Browser.new
b.goto "javascriptinjectedtablevalues.com" #not real website url:)
# desired urls in list are immediately located within <span> tags with a "class" of
#"name" plus a custom html attribute attribute of "data-bind" = "name: $data". that's it
# unless I wanted to use child-selectors which I'm not very good at
allrows = b.spans(:class => "name").each_with_index.map do |x, i|
[0, x.attribute_value("data-bind")]
end
real_row_ids = allrows.select{|i, databind| databind == "name: $data" }.map(&:first) #now I have all correct span ids
spans = real_row_ids.map {|id| b.spans(:class => "name")[id] }
Now that's a little messy in my opinion. But it leaves artifacts so I can debug and go back and stuff.
I could use this command to just grab a just the spans
spans = b.spans(:class => "name").map do |span|
[span, span.attribute_value("data-bind")]
end.select {|span, databind| databind == "name: $data"}.map(&:first)
but that still feels messy having no artifacts to show for it to use for later when trying to isolate other html tags nearby the span.
I'm hoping there is something like this pseudo code for watir:
b.spans(:class => "name").with_custom_attributes(:key => "data-bind", :value => "name: $data")
that's what I'd really like to do. superman-patching this custom method onto Watir within a rails initializer would be the optimal solution second to it already existing within Watir!
Watir already supports using data attributes for locators. You simply need to replace the dashes with underscores.
For example:
b.spans(:class => 'name', :data_bind => "name: $data")
Would match elements like:
<span class="name" data-bind="name: $data">
Similarly, you can use a regex when matching the data attribute:
b.spans(:class => 'name', :data_bind => /name/)

Setting a hyperlink text color in axlsx

I'm trying to set the foreground color of text in a hyperlink cell but it doesn't seem to work.
Using something like: sheet["A1"].color = "0000FF" works fine for a normal cell, but not for a hyperlinked cell
This code simply creates a link to cell D1 on the "Log" sheet (which works fine) but A1 never turns blue!
sheet.add_hyperlink :location => "'Log'!D1", :target => :sheet, :ref => "A1"
sheet["A1"].color = "0000FF"
Thanks!
There are two important things to do before applying a color to a link:
You have to define the color within a style, and
You have to know the exact address of the cell in question.
Styles are normally applied to rows, but in this case you want to apply it to a specific cell. This is possible, but you need to address the cell directly through the Sheet Object. Also, and somewhat counter intuitively, the 'add_hyperlink' method is available to the Sheet object, not the Cell. So beware of that as well.
Here is an example of how to apply a style to a cell containing a link:
p = Axlsx::Package.new
p.workbook do |wb|
wb.styles do |s|
blue_link = s.add_style :fg_color => '0000FF'
wb.add_worksheet(:name => "Anchor Link Test") do |sheet|
sheet.add_row ['Title', 'Link']
# Define the row here, we will use that later
row = sheet.add_row ['Google', 'Click to go']
# Add the hyperlink by addressing the column you have used and add 1 to the row's index value.
sheet.add_hyperlink :location => "http://www.google.com", :ref => "B#{row.index + 1}"
sheet["B#{row.index + 1}"].style = blue_link
end
s = p.to_stream()
File.open("anchor_link_test.xlsx", 'w') { |f| f.write(s.read) }
end
end
Final note: You might note that I have written this spreadsheet using the methods
s = p.to_stream()
File.open("anchor_link_test.xlsx", 'w') { |f| f.write(s.read) }
There is evidence presented on the Axlsx Github Issues Page which shows that this means of writing out the file is significantly faster than
p.serialize
Just thought that deserved mention somewhere on StackOverflow!
This seems to work:
require 'axlsx'
p = Axlsx::Package.new
ws = p.workbook.add_worksheet
ws.add_row ['hoge-hoge']
ws['A1'].color = '0000FF'
ws.add_hyperlink :location => 'F6', :target => :sheet, :ref => 'A1'
p.serialize 'where_is_my_color.xlsx'
Can you post a larger example of your code that does not set the color?
Apparently Axlsx is only applying custom styles to String data types. Fixed this by setting each column to type :string like this:
Sheet.add_row [ "1", "2", "3" ], :types => [:string, :string, :string]
Thanks Randy!

How to construct the 2d structure in a dynamic fashion

I iterate through all cars and its supported attributes (many attributes per car) to create a structure like this, how do I do this in a dynamic fashion.
cars = {
"honda" => {'color' => 'blue', 'type' => 'sedan'}.
"nissan" => {'color' => 'yellow', 'type' => 'sports'}.
...
}
cars.each do |car|
car_attrs = ...
car_attrs.each do |attr|
??? How to construct the above structure
end
end
Your question is not very clear... But i guess this is what you want:
cars = {}
options = {}
options['color'] = 'blue'
...
cars['honda'] = options
Is that what you were looking for?
It sounds like you may be asking for a way to create a 2-dimensional hash without having to explicitly create each child hash. One way to accomplish that is by specifying the default object created for a hash key.
# When we create the cars hash, we tell it to create a new Hash
# for undefined keys
cars = Hash.new { |hash, key| hash[key] = Hash.new }
# We can then assign values two-levels deep as follows
cars["honda"]["color"] = "blue"
cars["honda"]["type"] = "sedan"
cars["nissan"]["color"] = "yellow"
cars["nissan"]["type"] = "sports"
# But be careful not to check for nil using the [] operator
# because a default hash is now created when using it
puts "Found a Toyota" if cars["toyota"]
# The correct way to check would be
puts "Really found a Toyota" if cars.has_key? "toyota"
Many client libraries assume that the [] operator returns a nil default, so make sure other code doesn't depend on that behavior before using this solution. Good luck!
Assuming you are using something similar to ActiveRecord (but easy to modify if you are not):
cars_info = Hash[cars.map { |car| [car.name, car.attributes] }

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