Related
I'm working my first project using Neo4j. I'm parsing wikipedia's page and pagelinks dumps to create a graph where the nodes are pages and the edges are links.
I've defined some rake tasks that download the dumps, parse the data, and save it in a Neo4j database. At the end of the rake task I print the number of pages and links created, and some of the pages with the most links. Here is the output of the raks task for the zawiki.
$ rake wiki[zawiki]
[ omitted ]
...
:: Done parsing zawiki
:: 1984 pages
:: 2144 links
:: The pages with the most links are:
9625.0 - Emijrp/List_of_Wikipedians_by_number_of_edits_(bots_included): 40
1363.0 - Gvangjsih_Bouxcuengh_Swcigih: 30
9112.0 - Fuzsuih: 27
1367.0 - Cungzcoj: 26
9279.0 - Vangz_Yenfanh: 19
It looks like pages and links are being created, but when I start a rails console, or the server the links aren't found.
$ rails c
jruby-1.7.5 :013 > Pages.all.count
=> 1984
jruby-1.7.5 :003 > Pages.all.reduce(0) { |count, page| count + page.links.count}
=> 0
jruby-1.7.5 :012 > Pages.all.sort_by { |p| p.links.count }.reverse[0...5].map { |p| p.links.count }
=> [0, 0, 0, 0, 0]
Here is the rake task, and this is the projects github page. Can anyone tell me why the links aren't saved?
DUMP_DIR = Rails.root.join('lib','assets')
desc "Download wiki dumps and parse them"
task :wiki, [:wiki] => 'wiki:all'
namespace :wiki do
task :all, [:wiki] => [:get, :parse] do |t, args|
# Print info about the newly created pages and links.
link_count = 0
Pages.all.each do |page|
link_count += page.links.count
end
indent "Done parsing #{args[:wiki]}"
indent "#{Pages.count} pages"
indent "#{link_count} links"
indent "The pages with the most links are:"
Pages.all.sort_by { |a| a.links.count }.reverse[0...5].each do |page|
puts "#{page.page_id} - #{page.title}: #{page.links.count}"
end
end
desc "Download wiki page and page links database dumps to /lib/assets"
task :get, :wiki do |t, args|
indent "Downloading dumps"
sh "#{Rails.root.join('lib', "get_wiki").to_s} #{args[:wiki]}"
indent "Done"
end
desc "Parse all dumps"
task :parse, [:wiki] => 'parse:all'
namespace :parse do
task :all, [:wiki] => [:pages, :pagelinks]
desc "Read wiki page dumps from lib/assests into the database"
task :pages, [:wiki] => :environment do |t, args|
parse_dumps('page', args[:wiki]) do |obj|
page = Pages.create_from_dump(obj)
end
indent = "Created #{Pages.count} pages"
end
desc "Read wiki pagelink dumps from lib/assests into the database"
task :pagelinks, [:wiki] => :environment do |t, args|
errors = 0
parse_dumps('pagelinks', args[:wiki]) do |from_id, namespace, to_title|
from = Pages.find(:page_id => from_id)
to = Pages.find(:title => to_title)
if to.nil? || from.nil?
errors = errors.succ
else
from.links << to
from.save
end
end
end
end
end
def indent *args
print ":: "
puts args
end
def parse_dumps(dump, wiki_match, &block)
wiki_match ||= /\w+/
DUMP_DIR.entries.each do |file|
file, wiki = *(file.to_s.match(Regexp.new "(#{wiki_match})-#{dump}.sql"))
if file
indent "Parsing #{wiki} #{dump.pluralize} from #{file}"
each_value(DUMP_DIR.join(file), &block)
end
end
end
def each_value(filename)
f = File.open(filename)
num_read = 0
begin # read file until line starting with INSERT INTO
line = f.gets
end until line.match /^INSERT INTO/
begin
line = line.match(/\(.*\)[,;]/)[0] # ignore begining of line until (...) object
begin
yield line[1..-3].split(',').map { |e| e.match(/^['"].*['"]$/) ? e[1..-2] : e.to_f }
num_read = num_read.succ
line = f.gets.chomp
end while(line[0] == '(') # until next insert block, or end of file
end while line.match /^INSERT INTO/ # Until line doesn't start with (...
f.close
end
app/models/pages.rb
class Pages < Neo4j::Rails::Model
include Neo4j::NodeMixin
has_n(:links).to(Pages)
property :page_id
property :namespace, :type => Fixnum
property :title, :type => String
property :restrictions, :type => String
property :counter, :type => Fixnum
property :is_redirect, :type => Fixnum
property :is_new, :type => Fixnum
property :random, :type => Float
property :touched, :type => String
property :latest, :type => Fixnum
property :length, :type => Fixnum
property :no_title_convert, :type => Fixnum
def self.create_from_dump(obj)
# TODO: I wonder if there is a way to compine these calls
page = {}
# order of this array is important, it corresponds to the data in obj
attrs = [:page_id, :namespace, :title, :restrictions, :counter, :is_redirect,
:is_new, :random, :touched, :latest, :length, :no_title_convert]
attrs.each_index { |i| page[attrs[i]] = obj[i] }
page = Pages.create(page)
return page
end
end
I must admit that I have no idea of how Neo4j works.
Transferring from other databases though, I too assume that either some validation is wrong, or maybe even something is misconfigured in your use of the database. The latter I can't give any advice on where to look, but if it's about validation, you can look at Page#errors or try calling Page#save! and see what it raises.
One crazy idea that just came to mind looking at this example is that maybe for that relation to be configured properly, you need a back reference, too.
Maybe has_n(:links).to(Page, :links) will help you. Or, if that doesn't work:
has_n(:links_left).to(Page, :links_right)
has_n(:links_right).from(Page, :links_left)
The more I look at this, the more I think the back reference to the same table is not configured properly and thus won't validate.
Here is my code but it takes forever for huge files:
require 'rubygems'
require "faster_csv"
fname1 =ARGV[0]
fname2 =ARGV[1]
if ARGV.size!=2
puts "Display common lines in the two files \n Usage : ruby user_in_both_files.rb <file1> <file2> "
exit 0
end
puts "loading the CSV files ..."
file1=FasterCSV.read(fname1, :headers => :first_row)
file2=FasterCSV.read(fname2, :headers => :first_row)
puts "CSV files loaded"
#puts file2[219808].to_s.strip.gsub(/\s+/,'')
lineN1=0
lineN2=0
# count how many common lines
similarLines=0
file1.each do |line1|
lineN1=lineN1+1
#compare line 1 to all line from file 2
lineN2=0
file2.each do |line2|
puts "file1:l#{lineN1}|file2:l#{lineN2}"
lineN2=lineN2+1
if ( line1.to_s.strip.gsub(/\s+/,'') == line2.to_s.strip.gsub(/\s+/,'') )
puts "file1:l#{line1}|file2:l#{line2}->#{line1}\n"
similarLines=similarLines+1
end
end
end
puts "#{similarLines} similar lines."
Ruby has set operations available with arrays:
a_ary = [1,2,3]
b_ary = [3,4,5]
a_ary & b_ary # => 3
So, from that you should try:
puts "loading the CSV files ..."
file1 = FasterCSV.read(fname1, :headers => :first_row)
file2 = FasterCSV.read(fname2, :headers => :first_row)
puts "CSV files loaded"
common_lines = file1 & file2
puts common_lines.size
If you need to preprocess the arrays, do it as you load them:
file1 = FasterCSV.read(fname1, :headers => :first_row).map{ |l| l.to_s.strip.gsub(/\s+/, '') }
file2 = FasterCSV.read(fname2, :headers => :first_row).map{ |l| l.to_s.strip.gsub(/\s+/, '') }
You're gsubing File2 every time you loop through File1. I'd do that first, and then just compare the results of that.
Edit Something like this (untested)
file1lines = []
file1.each do |line1|
file1lines = line1.strip.gsub(/\s+/, '')
end
# Do the same for `file2lines`
file1lines.each do |line1|
lineN1=lineN1+1
#compare line 1 to all line from file 2
lineN2=0
file2lines.each do |line2|
puts "file1:l#{lineN1}|file2:l#{lineN2}"
lineN2=lineN2+1
if ( line1 == line2 )
puts "file1:l#{line1}|file2:l#{line2}->#{line1}\n"
similarLines=similarLines+1
end
end
end
I'd also get rid of all the putses in the loops unless you really need them. If the files are huge, that's probably slowing it down a noticeable amount.
I have a CSV file formatted just like this:
name,color,tasty,qty
apple,red,true,3
orange,orange,false,4
pear,greenish-yellowish,true,1
As you can see, each column in the Ruby OO world represents a mix of types -- string, string, boolean, int.
Now, ultimately, I want to parse each line in the file, determine the appropriate type, and insert that row into a database via a Rails migration. For ex:
Fruit.create(:name => 'apple', :color => 'red', :tasty => true, :qty => 3)
Help!
For Ruby 1.8:
require 'fastercsv'
FasterCSV.parse(my_string, :headers => true) do |row|
Fruit.create!(
:name => row['name'],
:color => row['color'],
:tasty => row['tasty'] == 'true',
:qty => row['qty].to_i
)
end
For Ruby 1.9, just rename FasterCSV to CSV and fastercsv to csv:
require 'csv'
CSV.parse(my_string, :headers => true) do |row|
# same as ruby-1.8
end
In PHP you can do:
print_r($var) or vardump($var)
which prints "human-readible" information about variable.
Is there equivalent functions / helpers for those in Ruby / Rails ?
In Rails templates you can do
<%= debug an_object %>
and it will do nice HTML PRE output.
Try using pp.
You will need to require it in scripts (or in irb if your .irbc doesn't already do this):
require 'pp'
Then you can 'PrettyPrint' an object thus:
pp object
Instead of requiring 'pp' and using pp, you can simply do
p object
Tested example
require 'pp'
class A
def initialize
#a = 'somevar'
#b = [1,2,3]
#c = {'var' => 'val'}
end
end
a = A.new
pp a # Gives -> #<A:0x2c6d048 #a="somevar", #b=[1, 2, 3], #c={"var"=>"val"}>
p a # Gives -> #<A:0x2c6d048 #a="somevar", #b=[1, 2, 3], #c={"var"=>"val"}>. No need to require 'pp'
There's the method inspect which helps. Sometimes calling the to_s method on an object will help (to_s returns a string representation of the object). You can also query methods, local_variables, class_variables, instance_variables, constants and global_variables.
p ['Hello',"G'day",'Bonjour','Hola'].inspect
# >> "[\"Hello\", \"G'day\", \"Bonjour\", \"Hola\"]"
p ['Hello',"G'day",'Bonjour','Hola'].to_s
# >> "HelloG'dayBonjourHola"
p Array.new.methods
# >> ["select", "[]=", "inspect", "compact"...]
monkey = 'baboon'
p local_variables
# >> ["monkey"]
class Something
def initialize
#x, #y = 'foo', 'bar'
##class_variable = 'gorilla'
end
end
p Something.class_variables
# >> ["##class_variable"]
s = Something.new
p s.instance_variables
# >> ["#x", "#y"]
p IO.constants
# >> ["TRUNC", "SEEK_END", "LOCK_SH"...]
p global_variables
# >> ["$-d", "$\"", "$$", "$<", "$_", "$-K"...]
I know this is an old post, but it is the first thing that Google pops up when searching for "Ruby equivalent of PHP print_r". I'm using Ruby in the command line mode, and there's really not a very good equivalent. "pp" is ok for fairly simple structures, but as soon as you start nesting hashes in arrays in hashes in more arrays, it turns into a jumble pretty fast. Since I haven't found a good emulation of print_r, I wrote one myself. It's good enough for my purposes, not overly complicated and I thought I'd share it to save other people some headache. Compare the output with the real PHP print_r
def print_r(inHash, *indent)
#indent = indent.join
if (inHash.class.to_s == "Hash") then
print "Hash\n#{#indent}(\n"
inHash.each { |key, value|
if (value.class.to_s =~ /Hash/) || (value.class.to_s =~ /Array/) then
print "#{#indent} [#{key}] => "
self.print_r(value, "#{#indent} ")
else
puts "#{#indent} [#{key}] => #{value}"
end
}
puts "#{#indent})\n"
elsif (inHash.class.to_s == "Array") then
print "Array\n#{#indent}(\n"
inHash.each_with_index { |value,index|
if (value.class.to_s == "Hash") || (value.class.to_s == "Array") then
print "#{#indent} [#{index}] => "
self.print_r(value, "#{#indent} ")
else
puts "#{#indent} [#{index}] => #{value}"
end
}
puts "#{#indent})\n"
end
# Pop last indent off
8.times {#indent.chop!}
end
Here's an example (made messy on purpose to show why the PHP print_r is so nice):
carTools = [ "Socket Set", "Combination Wrenches", "Oil Filter puller", "Brake Compressor" ]
houseTools =[ "Circular Saw", "Miter Saw", "Drill" ]
garageItems = Hash["Car1" => "Ford Mustang", "Car2" => "Honda Civic", "Bike1" => "IronHorse"]
garageItems["Tools"] = Hash["Car Tools" => carTools, "House Tools" => houseTools]
constructionSupplies = Hash["Plywood" => ["3/4\" T&G Plywood Sheets", "1/2\" Plywood Sheets"],
"Boards" => ["2x4s", "2x6s", "Engineered I-Joists"],
"Drywall" => ["4x8 1/2\" Sheetrock", "Mesh tape", "Paper tape", "Joint compount"]]
carParts = Hash["Mustang" => ["Clutch", "Transmission", "3.55 Ring & Pinion Gears", "Differential", "30# Injectors", "Pro-M 77mm MAF"]]
garageItems["Supplies"] = ["Oil", "WD40", constructionSupplies, carParts, "Brake Fluid"]
print_r(garageItems)
Output of print_r (actually comprehensible by a human):
Hash
(
[Car1] => Ford Mustang
[Car2] => Honda Civic
[Bike1] => IronHorse
[Tools] => Hash
(
[Car Tools] => Array
(
[0] => Socket Set
[1] => Combination Wrenches
[2] => Oil Filter puller
[3] => Brake Compressor
)
[House Tools] => Array
(
[0] => Circular Saw
[1] => Miter Saw
[2] => Drill
)
)
[Supplies] => Array
(
[0] => Oil
[1] => WD40
[2] => Hash
(
[Plywood] => Array
(
[0] => 3/4" T&G Plywood Sheets
[1] => 1/2" Plywood Sheets
)
[Boards] => Array
(
[0] => 2x4s
[1] => 2x6s
[2] => Engineered I-Joists
)
[Drywall] => Array
(
[0] => 4x8 1/2" Sheetrock
[1] => Mesh tape
[2] => Paper tape
[3] => Joint compount
)
)
[3] => Hash
(
[Mustang] => Array
(
[0] => Clutch
[1] => Transmission
[2] => 3.55 Ring & Pinion Gears
[3] => Differential
[4] => 30# Injectors
[5] => Pro-M 77mm MAF
)
)
[4] => Brake Fluid
)
)
Check out the guide for debugging rails:
http://guides.rubyonrails.com/debugging_rails_applications.html
hints:
script/console is great to try stuff in the context of your app
script/server --debugger to start the server with a debugger turned on, you can then use 'debug' in your code to break into an interactive shell
One approach I lean on a lot is this:
logger.debug "OBJECT: #{an_object.to_yaml}"
Easy to read, although it can get a little unwieldy for large objects.
Guess I'm a little late to this, but what about logger.info [debug|warning]? Use this from Controllers and Models. It will show up in your log files (development.log when in dev mode); and the above mentioned <%= debug("str: " + str) %> for views.
These aren't exact answers to your questions but you can also use script/console to load your rails app in to an interactive session.
Lastly, you can place debugger in a line of your rails application and the browser will "hang" when your app executes this line and you'll be able to be in a debug session from the exact line your placed your debugger in the source code.
I would like my JSON output in Ruby on Rails to be "pretty" or nicely formatted.
Right now, I call to_json and my JSON is all on one line. At times this can be difficult to see if there is a problem in the JSON output stream.
Is there way to configure to make my JSON "pretty" or nicely formatted in Rails?
Use the pretty_generate() function, built into later versions of JSON. For example:
require 'json'
my_object = { :array => [1, 2, 3, { :sample => "hash"} ], :foo => "bar" }
puts JSON.pretty_generate(my_object)
Which gets you:
{
"array": [
1,
2,
3,
{
"sample": "hash"
}
],
"foo": "bar"
}
The <pre> tag in HTML, used with JSON.pretty_generate, will render the JSON pretty in your view. I was so happy when my illustrious boss showed me this:
<% if #data.present? %>
<pre><%= JSON.pretty_generate(#data) %></pre>
<% end %>
Thanks to Rack Middleware and Rails 3 you can output pretty JSON for every request without changing any controller of your app. I have written such middleware snippet and I get nicely printed JSON in browser and curl output.
class PrettyJsonResponse
def initialize(app)
#app = app
end
def call(env)
status, headers, response = #app.call(env)
if headers["Content-Type"] =~ /^application\/json/
obj = JSON.parse(response.body)
pretty_str = JSON.pretty_unparse(obj)
response = [pretty_str]
headers["Content-Length"] = pretty_str.bytesize.to_s
end
[status, headers, response]
end
end
The above code should be placed in app/middleware/pretty_json_response.rb of your Rails project.
And the final step is to register the middleware in config/environments/development.rb:
config.middleware.use PrettyJsonResponse
I don't recommend to use it in production.rb. The JSON reparsing may degrade response time and throughput of your production app. Eventually extra logic such as 'X-Pretty-Json: true' header may be introduced to trigger formatting for manual curl requests on demand.
(Tested with Rails 3.2.8-5.0.0, Ruby 1.9.3-2.2.0, Linux)
If you want to:
Prettify all outgoing JSON responses from your app automatically.
Avoid polluting Object#to_json/#as_json
Avoid parsing/re-rendering JSON using middleware (YUCK!)
Do it the RAILS WAY!
Then ... replace the ActionController::Renderer for JSON! Just add the following code to your ApplicationController:
ActionController::Renderers.add :json do |json, options|
unless json.kind_of?(String)
json = json.as_json(options) if json.respond_to?(:as_json)
json = JSON.pretty_generate(json, options)
end
if options[:callback].present?
self.content_type ||= Mime::JS
"#{options[:callback]}(#{json})"
else
self.content_type ||= Mime::JSON
json
end
end
Check out Awesome Print. Parse the JSON string into a Ruby Hash, then display it with ap like so:
require "awesome_print"
require "json"
json = '{"holy": ["nested", "json"], "batman!": {"a": 1, "b": 2}}'
ap(JSON.parse(json))
With the above, you'll see:
{
"holy" => [
[0] "nested",
[1] "json"
],
"batman!" => {
"a" => 1,
"b" => 2
}
}
Awesome Print will also add some color that Stack Overflow won't show you.
If you find that the pretty_generate option built into Ruby's JSON library is not "pretty" enough, I recommend my own NeatJSON gem for your formatting.
To use it:
gem install neatjson
and then use
JSON.neat_generate
instead of
JSON.pretty_generate
Like Ruby's pp it will keep objects and arrays on one line when they fit, but wrap to multiple as needed. For example:
{
"navigation.createroute.poi":[
{"text":"Lay in a course to the Hilton","params":{"poi":"Hilton"}},
{"text":"Take me to the airport","params":{"poi":"airport"}},
{"text":"Let's go to IHOP","params":{"poi":"IHOP"}},
{"text":"Show me how to get to The Med","params":{"poi":"The Med"}},
{"text":"Create a route to Arby's","params":{"poi":"Arby's"}},
{
"text":"Go to the Hilton by the Airport",
"params":{"poi":"Hilton","location":"Airport"}
},
{
"text":"Take me to the Fry's in Fresno",
"params":{"poi":"Fry's","location":"Fresno"}
}
],
"navigation.eta":[
{"text":"When will we get there?"},
{"text":"When will I arrive?"},
{"text":"What time will I get to the destination?"},
{"text":"What time will I reach the destination?"},
{"text":"What time will it be when I arrive?"}
]
}
It also supports a variety of formatting options to further customize your output. For example, how many spaces before/after colons? Before/after commas? Inside the brackets of arrays and objects? Do you want to sort the keys of your object? Do you want the colons to all be lined up?
Dumping an ActiveRecord object to JSON (in the Rails console):
pp User.first.as_json
# => {
"id" => 1,
"first_name" => "Polar",
"last_name" => "Bear"
}
Using <pre> HTML code and pretty_generate is good trick:
<%
require 'json'
hash = JSON[{hey: "test", num: [{one: 1, two: 2, threes: [{three: 3, tthree: 33}]}]}.to_json]
%>
<pre>
<%= JSON.pretty_generate(hash) %>
</pre>
Here is a middleware solution modified from this excellent answer by #gertas. This solution is not Rails specific--it should work with any Rack application.
The middleware technique used here, using #each, is explained at ASCIIcasts 151: Rack Middleware by Eifion Bedford.
This code goes in app/middleware/pretty_json_response.rb:
class PrettyJsonResponse
def initialize(app)
#app = app
end
def call(env)
#status, #headers, #response = #app.call(env)
[#status, #headers, self]
end
def each(&block)
#response.each do |body|
if #headers["Content-Type"] =~ /^application\/json/
body = pretty_print(body)
end
block.call(body)
end
end
private
def pretty_print(json)
obj = JSON.parse(json)
JSON.pretty_unparse(obj)
end
end
To turn it on, add this to config/environments/test.rb and config/environments/development.rb:
config.middleware.use "PrettyJsonResponse"
As #gertas warns in his version of this solution, avoid using it in production. It's somewhat slow.
Tested with Rails 4.1.6.
#At Controller
def branch
#data = Model.all
render json: JSON.pretty_generate(#data.as_json)
end
If you're looking to quickly implement this in a Rails controller action to send a JSON response:
def index
my_json = '{ "key": "value" }'
render json: JSON.pretty_generate( JSON.parse my_json )
end
Here's my solution which I derived from other posts during my own search.
This allows you to send the pp and jj output to a file as needed.
require "pp"
require "json"
class File
def pp(*objs)
objs.each {|obj|
PP.pp(obj, self)
}
objs.size <= 1 ? objs.first : objs
end
def jj(*objs)
objs.each {|obj|
obj = JSON.parse(obj.to_json)
self.puts JSON.pretty_generate(obj)
}
objs.size <= 1 ? objs.first : objs
end
end
test_object = { :name => { first: "Christopher", last: "Mullins" }, :grades => [ "English" => "B+", "Algebra" => "A+" ] }
test_json_object = JSON.parse(test_object.to_json)
File.open("log/object_dump.txt", "w") do |file|
file.pp(test_object)
end
File.open("log/json_dump.txt", "w") do |file|
file.jj(test_json_object)
end
I have used the gem CodeRay and it works pretty well. The format includes colors and it recognises a lot of different formats.
I have used it on a gem that can be used for debugging rails APIs and it works pretty well.
By the way, the gem is named 'api_explorer' (http://www.github.com/toptierlabs/api_explorer)
if you want to handle active_record object, puts is enough.
for example:
without puts
2.6.0 (main):0 > User.first.to_json
User Load (0.4ms) SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1 [["LIMIT", 1]]
=> "{\"id\":1,\"admin\":true,\"email\":\"admin#gmail.com\",\"password_digest\":\"$2a$10$TQy3P7NT8KrdCzliNUsZzuhmo40LGKoth2hwD3OI.kD0lYiIEwB1y\",\"created_at\":\"2021-07-20T08:34:19.350Z\",\"updated_at\":\"2021-07-20T08:34:19.350Z\",\"name\":\"Arden Stark\"}"
with puts
2.6.0 (main):0 > puts User.first.to_json
User Load (0.3ms) SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT $1 [["LIMIT", 1]]
{"id":1,"admin":true,"email":"admin#gmail.com","password_digest":"$2a$10$TQy3P7NT8KrdCzliNUsZzuhmo40LGKoth2hwD3OI.kD0lYiIEwB1y","created_at":"2021-07-20T08:34:19.350Z","updated_at":"2021-07-20T08:34:19.350Z","name":"Arden Stark"}
=> nil
if you are handle the json data, JSON.pretty_generate is a good alternative
Example:
obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}}
json = JSON.pretty_generate(obj)
puts json
Output:
{
"foo": [
"bar",
"baz"
],
"bat": {
"bam": 0,
"bad": 1
}
}
if it's in the ROR project, I always prefer to use gem pry-rails to format my codes in the rails console rather than awesome_print which is too verbose.
Example of pry-rails:
it also has syntax highlight.
# example of use:
a_hash = {user_info: {type: "query_service", e_mail: "my#email.com", phone: "+79876543322"}, cars_makers: ["bmw", "mitsubishi"], car_models: [bmw: {model: "1er", year_mfc: 2006}, mitsubishi: {model: "pajero", year_mfc: 1997}]}
pretty_html = a_hash.pretty_html
# include this module to your libs:
module MyPrettyPrint
def pretty_html indent = 0
result = ""
if self.class == Hash
self.each do |key, value|
result += "#{key}: #{[Array, Hash].include?(value.class) ? value.pretty_html(indent+1) : value}"
end
elsif self.class == Array
result = "[#{self.join(', ')}]"
end
"#{result}"
end
end
class Hash
include MyPrettyPrint
end
class Array
include MyPrettyPrint
end
Simplest example, I could think of:
my_json = '{ "name":"John", "age":30, "car":null }'
puts JSON.pretty_generate(JSON.parse(my_json))
Rails console example:
core dev 1555:0> my_json = '{ "name":"John", "age":30, "car":null }'
=> "{ \"name\":\"John\", \"age\":30, \"car\":null }"
core dev 1556:0> puts JSON.pretty_generate(JSON.parse(my_json))
{
"name": "John",
"age": 30,
"car": null
}
=> nil
Pretty print variant (Rails):
my_obj = {
'array' => [1, 2, 3, { "sample" => "hash"}, 44455, 677778, nil ],
foo: "bar", rrr: {"pid": 63, "state with nil and \"nil\"": false},
wwww: 'w' * 74
}
require 'pp'
puts my_obj.as_json.pretty_inspect.
gsub('=>', ': ').
gsub(/"(?:[^"\\]|\\.)*"|\bnil\b/) {|m| m == 'nil' ? 'null' : m }.
gsub(/\s+$/, "")
Result:
{"array": [1, 2, 3, {"sample": "hash"}, 44455, 677778, null],
"foo": "bar",
"rrr": {"pid": 63, "state with nil and \"nil\"": false},
"wwww":
"wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww"}
If you are using RABL you can configure it as described here to use JSON.pretty_generate:
class PrettyJson
def self.dump(object)
JSON.pretty_generate(object, {:indent => " "})
end
end
Rabl.configure do |config|
...
config.json_engine = PrettyJson if Rails.env.development?
...
end
A problem with using JSON.pretty_generate is that JSON schema validators will no longer be happy with your datetime strings. You can fix those in your config/initializers/rabl_config.rb with:
ActiveSupport::TimeWithZone.class_eval do
alias_method :orig_to_s, :to_s
def to_s(format = :default)
format == :default ? iso8601 : orig_to_s(format)
end
end
I use the following as I find the headers, status and JSON output useful as
a set. The call routine is broken out on recommendation from a railscasts presentation at: http://railscasts.com/episodes/151-rack-middleware?autoplay=true
class LogJson
def initialize(app)
#app = app
end
def call(env)
dup._call(env)
end
def _call(env)
#status, #headers, #response = #app.call(env)
[#status, #headers, self]
end
def each(&block)
if #headers["Content-Type"] =~ /^application\/json/
obj = JSON.parse(#response.body)
pretty_str = JSON.pretty_unparse(obj)
#headers["Content-Length"] = Rack::Utils.bytesize(pretty_str).to_s
Rails.logger.info ("HTTP Headers: #{ #headers } ")
Rails.logger.info ("HTTP Status: #{ #status } ")
Rails.logger.info ("JSON Response: #{ pretty_str} ")
end
#response.each(&block)
end
end
I had a JSON object in the rails console, and wanted to display it nicely in the console (as opposed to displaying like a massive concatenated string), it was as simple as:
data.as_json