ChristianKakesa

https://twitter.com/christiankakesa

https://plus.google.com/+ChristianKakesa

RATP-SIT/CPS/SDP

WhatisRuby?WhousesRuby?RumorsaboutRubyWhyRuby?RubyforjavanerosRubyforphperosDeepinspection(part2-Rubytime)VirtualmachinesThelanguageUsageIdiomsEcosystemPracticewithRubyOnRailsLearnRuby

ProgramminglanguageCreatedbyYukihiroMatsumotoCreatedin1993(firstreleasein1995)Inspiredby:Smalltalk,Perl,Lisp,Python,...

https://thecoderfactory.com/posts/top-15-sites-built-with-ruby-on-rails

Yesbut,RubyisoneofthemostfastestdynamiclanguageMostofthetimewearedealingwiththenetwork

puts"BecauseI'mhappy"BecauseI'mhappy=>nil

#Sum1,3,5,7,9,11,13[1,3,5,7,11,13].inject{|a,b|a+b}=>40

#Findthelengthofallthestrings["test","hellothere","how'slifetoday?"].collect{|string|string.length}=>[4,11,17]##or["test","hellothere","how'slifetoday?"].collect(&:length)=>[4,11,17]

== !=GarbagecollectorObjectsarestronglytypedMethodsencapsulation

publicprivateprotected

DocumentationRubydocJavadoc

PartofCfamily...

NocompilationNostatictypeNocastingNativethreadswithGILNoprimitives:

byte,short,int,long,float,double,boolean,char

...

== !=DynamicallytypedEvalLargestandardlibraryArraysandHashworkasexpectedHeredocs:'<<'or'<<-'(php:'<<<')PartofCfamily...

EverythingisanobjectNoabstractclassesorinterfacesbutmodulesAlmosteverythingisamethodcall:...

Crossplatform:GNU/Linux,Mac,Windows,BSD's,Solaris,...ObjectorientedVariablesarenottypedClasses,inheritanceandmixinsThreads(GILfornow)IteratorsandclosuresGarbagecollectionExceptionhandlingRegularexpressionsPowerfulstringoperationsOperatoroverloadingIntrospection,reflexion,metaprogrammingDucktypinglanguage...

NumericIntegerFloatsComplexRationalBigDecimal

String:'',"",+,character,...SymbolArrayHashBooleanNil:neutral,a ,notpresent

Set,Struct,...nnihilation

#Numeric1+1#=>21.+(1)#=>22.0**3#=>8.0Complex(2,3)#=>(2+3i)Rational(1)#=>(1/1)BigDecimal.new("1.0")/BigDecimal.new("0.0")#=>InfinityBigDecimal.new("-1.0")/BigDecimal.new("0.0")#=>-Infinity

#String,characterputs'I\'mHappy'#=>I'mHappybang='!'puts"I'mHappytoo#{bang}"#=>I'mHappytoo!puts'Hello'+'world'#=>Helloworldputs'ABCD'[1]#=>B

#Symbolf=:terms;s=:termsputsf.object_id#=>544328putss.object_id#=>544328

#Array,Hash[1,2,3,4,5,6]#=>[1,2,3,4,5,6]{f:42,s:4242}#=>{:f=>42,:s=>4242}

#Booleant=true#=>truet.class#=>TrueClassf=false#=>falsef.class#=>FalseClass

#ifexpressionmy_array=[]ifmy_array.empty?thenputs'Empty'end

res=42ifres==42puts"You'reright"endputs"You'reright"ifres==42

#unlessexpression(evaluate'false'or'nil')unlessres==42puts"You'rewrong"endputs"You'rewrong"unlessres==42puts"You'rewrong"ifnotres==42puts"You'rewrong"if!(res==42)

#if-elsif-elseexpressiona=[2,24,1,32,9,78]ifa.include?(42)puts"It'ssotrue"elsifa.empty?puts"I'mempty"elsifa.include?(nil)puts"Nilishere"elseputs'Nothingtodo'end

#ternaryoperatorputsres==42?"You'reright":"You'rewrong"##puts(ifres==42then"You'reright"else"You'rewrong"end)

#casewhens='127.0.0.1-srv[10/Oct/2000:13:55:36-0700]"GET/apache.gifHTTP/1.0"2002326'caseswhen/GET/puts"It'sanHTTPGETcommand"whenStringputs"Thisisastring"whenIntegerputs"Thisisainteger"when/^127.0.0.1/,/srv/puts"I'monthesamemachine"elseputs'Nothingtodo'end

#Loops:while,until,forina=[1,2,3,4,5]whilea.size>0#TrueClassprint"#{a.pop},"end#=>5,4,3,2,1,

a=[1,2,3,4,5]untila.empty?#FalseClassprint"#{a.pop},"end#=>5,4,3,2,1,

foriin1..5#Enumeratorprint"#{i},"end#=>1,2,3,4,5,

##next:gotothenextconditionforiin1..5#Enumeratornextifi<2print"#{i},"end#=>2,3,4,5,

##break:gooutoftheloopa=[1,2,3,4,5]untila.empty?#FalseClassbreakifa.size==2print"#{a.pop},"end#=>5,4,3,

#redo:onlythecurrentiteration(0..4).eachdo|i|puts"v:#{i}"redoifi>3end#v:0#v:1#v:2#v:3#v:4#v:4#...Infiniteloop..

#classclassMonkeyattr_reader:bananas#,...#defbananas#@bananas#end

attr_writer:mangos#,...#defmangos=(val)#@mangos=val#end

attr_accessor:papayas#,...#attr_reader:papayas#attr_writer:papayas

#Constructorisoptionaldefinitialize@bananas=42@@fruits=4242end

defmethod1#Dosomething...endend

m=Monkey.newm.method1

#classinheritanceclassMonkeyBis<Monkey#classmethoddefself.make_happyputs"I'mhappy"end#class<<self#defmake_happy#puts"I'mhappy"#end#defanother##...#end#endend

MonkeyBis.make_happy#=>I'mhappy

extendsinclude...

#begin,rescue,ensurebegin#..processf=File.open('42.txt','r')rescueIOError=>eputs'Errorhere!'rescue#..Allothererrorselseputs"Congratulations--noerrors!"ensuref.closeunlessf.nil?end

#raiseraiseraise"Thereissomethingwrong"##caller:HandlethestacktraceforthiserrorraiseCustomOrStandardException,"Failuremassage",Kernel::caller

#retry:restarttheentireblocofcodebeginforiin0..4puts"v:#{i}"raiseifi>2endrescueretryend#v:0#v:1#v:2#v:3#v:0#...Infiniteloop..

#Lambda,numberofparametersmustmatch!defmeth#my_lambda=->{return"I'msick"}my_lambda=lambda{return"I'msick"}my_lambda.call

return"I'mOK"end

putsmeth#=>I'mOK

#Proc,'return'fromthemethodandnottheprocdefmeth#my_proc=proc{return"I'msick"}my_proc=Proc.new{return"I'msick"}my_proc.call

return"I'mOK"end

putsmeth#=>I'msick

#Onelinecomment

=beginBlocofcommentdefmeth#my_lambda=->{return"I'msick"}my_lambda=lambda{return"I'msick"}my_lambda.callreturn"I'mOK"end=end

classPersondeftalkputs'Lassmichinruhe!'endend#Person.new().talk()Person.new.talk#=>Lassmichinruhe!

classPersondeftalkputs'Lassmichinruhe!';puts'Writecorrectly!';puts'Thisisgood!'endendPerson.new.talk#=>Lassmichinruhe!#=>Writecorrectly!#=>Thisisgood!

#'?':MethodreturningabooleanvalueclassUserdefis_admin?falseendend

user=User.newputs"I'mnotanadmin"unlessuser.is_admin?#=>I'mnotanadmin

#'!':Dangerousmethod,preventthedeveloperclassUser#...

defadmin_protect!exit42unlessself.is_admin?puts'Somethingelse'endend

user=User.newuser.admin_protect!#=>//Exittheprogramme

1.is_a?Object#=>true1.class#=>FixnumFixnum.is_a?Object#=>true''.class#=>String

#send##"uppercaseme".upcaseputs"uppercaseme".send(:upcase)#=>UPPERCASEME

#instancevariableclassVars;endv=Vars.new{var1:1,var2:2}.eachdo|name,value|v.instance_variable_set("@#{name}",value)end

puts"var1:#{v.instance_variable_get('@var1')}"puts"var2:#{v.instance_variable_get('@var2')}"#=>var1:1#=>var2:2

#class_eval

classGuess#definitialize#@what=42#end

#defwhat#@what#endend

Guess.class_eval('definitialize;@what=42;end')Guess.class_eval{defwhat;@what;end}

Guess.what#=>NoMethodError:undefinedmethod`what'forMonk:Class...

g=Guess.newputsg.what#=>42

#instance_eval

classPerson#defself.human?#true#endend

Person.instance_evaldodefhuman?trueendend

putsPerson.human??'Yes':'No'#=>Yes

#More:eval,module_eval,define_method,...

#WindowsManagementIntrumentation##ListallUSBdevicesrequire'win32ole'

wmi=WIN32OLE.connect("winmgmts://")

devices=wmi.ExecQuery("Select*FromWin32_USBControllerDevice")fordeviceindevicesdodevice_name=device.Dependent.gsub('"','').split('=')[1]usb_devices=wmi.ExecQuery("Select*FromWin32_PnPEntityWhereDeviceID='#{device_name}'")forusb_deviceinusb_devicesdoputsusb_device.Descriptionifusb_device.Description=='USBMassStorageDevice'#DOSOMETHINGHEREendendend

#RegistryaccessorlibraryforWindowsrequire'win32/registry'keyname='SYSTEM\\CurrentControlSet\\Control\\SessionManager\\Environment'

#KEY_ALL_ACCESSenablesyoutowriteanddeleted.#thedefaultaccessisKEY_READifyouspecifynothingaccess=Win32::Registry::KEY_ALL_ACCESS

Win32::Registry::HKEY_LOCAL_MACHINE.open(keyname,access)do|reg|#eachisthesameaseach_value,because#each_keyactuallymeans#"eachchildfolder"so#eachdoesn'tlistanychildfolders...#use#keysforthat...reg.each{|name,value|putsname,value}end

[1,2,3].map{|x|2*x}#=>[2,4,6]##singlelineor'do..end'

[1,2,3].mapdo|x|2*xend

unlessdone#multiplelines...end

if!done#multiplelines...end#orifnotdone#multiplelines...end

ifdonesingle_expresion_or_methodend

single_expresion_or_methodifdone

putsmy_value.to_sifmy_value if!my_value.nil?putsmy_value.to_send

MorewithRubyidiomshttps://code.google.com/p/tokland/wiki/RubyIdioms

Rubygems:RubypackageBundler:Manageapplication'sgemsdependencies

:Rack,Rake,ActiveRecord,Brakeman,...RVM,Rbenv:RubyversionmanagerPuppet, :Configurationmanagementfor

:Deploymanagementutility:Testingtool

Rdoc:Rubydocumentation:securitytestingtool,

...

geminstallrailsrailsnewsdp_blogcdsdp_blograilsserver

railsgeneratecontrollerhomeindex

#config/route.rb#...#root'home#index'#...

railsgeneratescaffoldArticletitle:stringdescription:textrakedb:migrate

#Addatwitterbootstrapgemin'Gemfile'#gem'bootstrap-sass','~>3.3.0'

#AddBootstrapinproject##app/assets/stylesheets/application.css.scss#@import"bootstrap-sprockets";#@import"bootstrap";

##app/assets/javascripts/application.js#...#//=requirebootstrap-sprockets#...

IRB(REPL)Rubyin20minutes:TryRuby(onlineRubyconsole):Rubywarrior, :Codecademy:

English:French:

https://www.ruby-lang.org/en/documentation/quickstart/

http://tryruby.org/https://www.bloc.io/ruby-warrior

http://www.codecademy.com/glossary/rubyhttp://www.codecademy.com/fr/glossary/ruby