DOCSLIB.ORG

Neo4j.Rb Documentation Release 8.2.5

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Neo4j.Rb Documentation Release 8.2.5 Neo4j.rb Documentation Release 8.2.5 Chris Grigg, Brian Underwood Sep 25, 2017 Contents 1 Introduction 3 1.1 Terminology...............................................3 1.1.1 Neo4j..............................................3 1.1.2 Neo4j.rb.............................................4 1.2 Code Examples..............................................4 1.2.1 ActiveNode...........................................4 1.3 Setup...................................................4 2 Setup 5 2.1 Ruby on Rails..............................................5 2.1.1 Generating a new app......................................5 2.1.2 Adding the gem to an existing project.............................6 2.1.3 Rails configuration.......................................6 2.1.4 Configuring Faraday......................................7 2.2 Any Ruby Project............................................8 2.2.1 Connection...........................................8 2.3 What if I’m integrating with a pre-existing Neo4j database?......................9 2.4 Heroku..................................................9 3 Upgrade Guide 11 3.1 What has changed............................................ 11 3.2 The neo4j-core gem......................................... 11 3.2.1 The new API.......................................... 12 3.3 The neo4j gem............................................. 13 3.3.1 Sessions............................................. 13 3.3.2 server_db............................................ 13 3.3.3 Outside of Rails......................................... 14 3.3.4 Indexes and Constraints..................................... 14 3.3.5 Migrations............................................ 15 3.3.6 neo_id id_properties...................................... 15 3.3.7 Exceptions........................................... 15 4 Rake Tasks 17 5 ActiveNode 19 5.1 Properties................................................. 19 5.1.1 Labels.............................................. 20 i 5.1.2 Indexes and Constraints..................................... 20 5.1.3 Labels.............................................. 20 5.1.4 Serialization........................................... 21 5.1.5 Enums.............................................. 21 5.2 Scopes.................................................. 22 5.3 Wrapping................................................. 24 5.4 Callbacks................................................. 24 5.5 created_at, updated_at.......................................... 24 5.6 Validation................................................. 24 5.7 id property (primary key)........................................ 25 5.8 Associations............................................... 25 5.8.1 Updating Associations..................................... 26 5.8.2 Dependent Associations.................................... 26 5.8.3 Creating Unique Relationships................................. 26 5.8.4 Eager Loading......................................... 27 6 ActiveRel 29 6.1 When to Use?.............................................. 29 6.2 Setup................................................... 29 6.3 Relationship Creation.......................................... 30 6.3.1 From an ActiveRel Model................................... 30 6.3.2 From a has_many or has_one association........................... 31 6.3.3 Creating Unique Relationships................................. 31 6.4 Query and Loading existing relationships................................ 31 6.4.1 :each_rel, :each_with_rel, or :pluck methods.......................... 31 6.5 Accessing related nodes......................................... 31 6.6 Advanced Usage............................................. 32 6.6.1 Separation of Relationship Logic................................ 32 6.7 Additional methods........................................... 33 6.8 Regarding: from and to......................................... 33 7 Properties 35 7.1 Undeclared Properties.......................................... 36 7.1.1 Types and Conversion...................................... 36 7.1.2 Custom Converters....................................... 37 8 Unique IDs 39 8.1 Defining your own ID.......................................... 39 8.2 Using internal Neo4j IDs as id_property................................. 40 8.3 A note regarding constraints....................................... 40 8.4 Adding IDs to Existing Data....................................... 40 8.5 Working with Legacy Schemas..................................... 40 9 Querying 43 9.1 Introduction............................................... 43 9.2 ActiveNode................................................ 43 9.2.1 Simple Query Methods..................................... 43 9.2.2 Proxy Method Chaining.................................... 44 9.2.3 The Query API......................................... 47 9.2.4 #proxy_as............................................ 48 9.2.5 match_to and first_rel_to ............................... 48 9.2.6 Finding in Batches....................................... 48 9.2.7 Orm_Adapter.......................................... 48 9.2.8 Find or Create By.......................................... 49 ii 10 QueryClauseMethods 51 10.1 Neo4j::Core::Query........................................... 51 10.1.1 #match............................................. 51 10.1.2 #optional_match........................................ 54 10.1.3 #using.............................................. 54 10.1.4 #where............................................. 55 10.1.5 #where_not........................................... 59 10.1.6 #match_nodes.......................................... 61 10.1.7 #unwind............................................. 62 10.1.8 #return.............................................. 63 10.1.9 #order.............................................. 64 10.1.10 #limit.............................................. 66 10.1.11 #skip.............................................. 67 10.1.12 #with.............................................. 68 10.1.13 #create.............................................. 69 10.1.14 #create_unique......................................... 71 10.1.15 #merge............................................. 72 10.1.16 #delete.............................................. 73 10.1.17 #set_props............................................ 74 10.1.18 #set............................................... 75 10.1.19 #on_create_set......................................... 76 10.1.20 #on_match_set......................................... 77 10.1.21 #remove............................................. 78 10.1.22 #start.............................................. 79 10.1.23 clause combinations....................................... 80 11 Configuration 85 11.1 In Rails.................................................. 85 11.2 Other Ruby apps............................................. 85 11.3 Variables................................................. 85 11.4 Instrumented events........................................... 87 12 Migrations 89 12.1 Generators................................................ 89 12.2 Transactions............................................... 90 12.3 The schema file.............................................. 90 12.4 Tasks................................................... 90 12.4.1 neo4j:migrate:all........................................ 90 12.4.2 neo4j:migrate.......................................... 90 12.4.3 neo4j:migrate:up........................................ 91 12.4.4 neo4j:migrate:down....................................... 91 12.4.5 neo4j:migrate:status....................................... 91 12.4.6 neo4j:rollback.......................................... 91 12.4.7 neo4j:schema:dump....................................... 91 12.4.8 neo4j:schema:load....................................... 91 12.5 Integrate Neo4j.rb with ActiveRecord migrations............................ 92 12.6 Migration Helpers............................................ 92 12.6.1 #execute............................................. 92 12.6.2 #query.............................................. 92 12.6.3 #remove_property........................................ 92 12.6.4 #rename_property........................................ 92 12.6.5 #drop_nodes.......................................... 92 12.6.6 #add_label............................................ 93 12.6.7 #add_labels........................................... 93 iii 12.6.8 #remove_label......................................... 93 12.6.9 #remove_labels......................................... 93 12.6.10 #rename_label.......................................... 93 12.6.11 #add_constraint......................................... 93 12.6.12 #drop_constraint........................................ 93 12.6.13 #add_index........................................... 94 12.6.14 #drop_index........................................... 94 12.6.15 #say............................................... 94 12.6.16 #say_with_time......................................... 94 12.6.17 #populate_id_property..................................... 95 12.6.18 #relabel_relation........................................ 95 12.6.19 #change_relations_style.................................... 95 13 Testing 97 13.1 How to clear the database........................................ 97 13.1.1 Cypher............................................. 97 13.1.2 Delete data files......................................... 97 13.1.3 RSpec Transaction Rollback.................................
Load more

Recommended publications
  • TECHNICAL STANDARDS a Standards Validation Committee of Industry Representatives and Educators Reviewed and Updated These Standards on December 11, 2017
    SOFTWARE AND APP DESIGN 15.1200.40 TECHNICAL STANDARDS A Standards Validation Committee of industry representatives and educators reviewed and updated these standards on December 11, 2017. Completion of the program prepares students to meet the requirements of one or more industry certification: Cybersecurity Fundamentals Certificate, Oracle Certified Associate, Java SE 8 Programmer, Certified Internet Web (CIW) - JavaScript Specialist, CompTIA A+, CompTIA IT Fundamentals, CSX Cybersecurity Fundamentals Certificate, and Microsoft Technology Associate (MTA). The Arizona Career and Technical Education Quality Commission, the validating entity for the Arizona Skills Standards Assessment System, endorsed these standards on January 25, 2018. Note: Arizona’s Professional Skills are taught as an integral part of the Software and App Design program. The Technical Skills Assessment for Software and App Design is available SY2020-2021. Note: In this document i.e. explains or clarifies the content and e.g. provides examples of the content that must be taught. STANDARD 1.0 APPLY PROBLEM-SOLVING AND CRITICAL THINKING SKILLS 1.1 Establish objectives and outcomes for a task 1.2 Explain the process of decomposing a large programming problem into smaller, more manageable procedures 1.3 Explain “visualizing” as a problem-solving technique prior to writing code 1.4 Describe problem-solving and troubleshooting strategies applicable to software development STANDARD 2.0 RECOGNIZE SECURITY ISSUES 2.1 Identify common computer threats (e.g., viruses, phishing,
    [Show full text]
  • Seisio: a Fast, Efficient Geophysical Data Architecture for the Julia
    1 SeisIO: a fast, efficient geophysical data architecture for 2 the Julia language 1∗ 2 2 2 3 Joshua P. Jones , Kurama Okubo , Tim Clements , and Marine A. Denolle 1 4 4509 NE Sumner St., Portland, OR, USA 2 5 Department of Earth and Planetary Sciences, Harvard University, MA, USA ∗ 6 Corresponding author: Joshua P. Jones ([email protected]) 1 7 Abstract 8 SeisIO for the Julia language is a new geophysical data framework that combines the intuitive 9 syntax of a high-level language with performance comparable to FORTRAN or C. Benchmark 10 comparisons with recent versions of popular programs for seismic data download and analysis 11 demonstrate significant improvements in file read speed and orders-of-magnitude improvements 12 in memory overhead. Because the Julia language natively supports parallel computing with an 13 intuitive syntax, we benchmark test parallel download and processing of multi-week segments of 14 contiguous data from two sets of 10 broadband seismic stations, and find that SeisIO outperforms 15 two popular Python-based tools for data downloads. The current capabilities of SeisIO include file 16 read support for several geophysical data formats, online data access using FDSN web services, 17 IRIS web services, and SeisComP SeedLink, with optimized versions of several common data 18 processing operations. Tutorial notebooks and extensive documentation are available to improve 19 the user experience (UX). As an accessible example of performant scientific computing for the 20 next generation of researchers, SeisIO offers ease of use and rapid learning without sacrificing 21 computational performance. 2 22 1 Introduction 23 The dramatic growth in the volume of collected geophysical data has the potential to lead to 24 tremendous advances in the science (https://ds.iris.edu/data/distribution/).
    [Show full text]
  • Empirical Study of Restarted and Flaky Builds on Travis CI
    Empirical Study of Restarted and Flaky Builds on Travis CI Thomas Durieux Claire Le Goues INESC-ID and IST, University of Lisbon, Portugal Carnegie Mellon University [email protected] [email protected] Michael Hilton Rui Abreu Carnegie Mellon University INESC-ID and IST, University of Lisbon, Portugal [email protected] [email protected] ABSTRACT Continuous integration is an automatic process that typically Continuous Integration (CI) is a development practice where devel- executes the test suite, may further analyze code quality using static opers frequently integrate code into a common codebase. After the analyzers, and can automatically deploy new software versions. code is integrated, the CI server runs a test suite and other tools to It is generally triggered for each new software change, or at a produce a set of reports (e.g., the output of linters and tests). If the regular interval, such as daily. When a CI build fails, the developer is result of a CI test run is unexpected, developers have the option notified, and they typically debug the failing build. Once the reason to manually restart the build, re-running the same test suite on for failure is identified, the developer can address the problem, the same code; this can reveal build flakiness, if the restarted build generally by modifying or revoking the code changes that triggered outcome differs from the original build. the CI process in the first place. In this study, we analyze restarted builds, flaky builds, and their However, there are situations in which the CI outcome is unex- impact on the development workflow.
    [Show full text]
  • User Guide for HCR Estimator 2.0: Software to Calculate Cost and Revenue Thresholds for Harvesting Small-Diameter Ponderosa Pine
    United States Department of Agriculture User Guide for HCR Forest Service Estimator 2.0: Software Pacific Northwest Research Station to Calculate Cost and General Technical Report PNW-GTR-748 Revenue Thresholds April 2008 for Harvesting Small- Diameter Ponderosa Pine Dennis R. Becker, Debra Larson, Eini C. Lowell, and Robert B. Rummer The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of multiple use management of the Nation’s forest resources for sustained yields of wood, water, forage, wildlife, and recreation. Through forestry research, cooperation with the States and private forest owners, and management of the National Forests and National Grasslands, it strives—as directed by Congress—to provide increasingly greater service to a growing Nation. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, 1400 Independence Avenue, SW, Washington, DC 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. Authors Dennis R.
    [Show full text]
  • Ola Bini Computational Metalinguist [email protected] 698E 2885 C1DE 74E3 2CD5 03AD 295C 7469 84AF 7F0C
    JRuby For The Win Ola Bini computational metalinguist [email protected] http://olabini.com/blog 698E 2885 C1DE 74E3 2CD5 03AD 295C 7469 84AF 7F0C onsdag 12 juni 13 Logistics and Demographics onsdag 12 juni 13 LAST MINUTE DEMO onsdag 12 juni 13 JRuby Implementation of the Ruby language Java 1.6+ 1.8.7 and 1.9.3 compatible (experimental 2.0 support) Open Source Created 2001 Embraces testing Current version: 1.7.4 Support from EngineYard, RedHat & ThoughtWorks onsdag 12 juni 13 Why JRuby? Threading Unicode Performance Memory Explicit extension API and OO internals Libraries and legacy systems Politics onsdag 12 juni 13 InvokeDynamic onsdag 12 juni 13 JRuby Differences Most compatible alternative implementation Native threads vs Green threads No C extensions (well, some) No continuations No fork ObjectSpace disabled by default onsdag 12 juni 13 Simple JRuby onsdag 12 juni 13 Java integration Java types == Ruby types Call methods, construct instances Static generation of classes camelCase or snake_case .getFoo(), setFoo(v) becomes .foo and .foo = v Interfaces can be implemented Classes can be inherited from Implicit closure conversion Extra added features to Rubyfy Java onsdag 12 juni 13 Ant+Rake onsdag 12 juni 13 Clojure STM onsdag 12 juni 13 Web onsdag 12 juni 13 Rails onsdag 12 juni 13 Sinatra onsdag 12 juni 13 Trinidad onsdag 12 juni 13 Swing Swing API == large and complex Ruby magic simplifies most of the tricky bits Java is a very verbose language Ruby makes Swing fun (more fun at least) No consistent cross-platform GUI library for Ruby
    [Show full text]
  • Usage, Costs, and Benefits of Continuous Integration in Open
    Usage, Costs, and Benefits of Continuous Integration in Open-Source Projects Michael Hilton Timothy Tunnell Kai Huang Oregon State University University of Illinois at University of Illinois at [email protected] Urbana-Champaign Urbana-Champaign [email protected] [email protected] Darko Marinov Danny Dig University of Illinois at Oregon State University Urbana-Champaign [email protected] [email protected] ABSTRACT CI using several quality metrics. However, the study does Continuous integration (CI) systems automate the compi- not present any detailed information about the use of CI. lation, building, and testing of software. Despite CI rising In fact, despite some folkloric evidence about the use of CI, as a big success story in automated software engineering, it there is no systematic study about CI systems. has received almost no attention from the research commu- Not only do we lack basic knowledge about the extent nity. For example, how widely is CI used in practice, and to which open-source projects are adopting CI, but also what are some costs and benefits associated with CI? With- we have no answers to many other important questions re- out answering such questions, developers, tool builders, and lated to CI. What are the costs of CI? Does CI deliver researchers make decisions based on folklore instead of data. on the promised benefits, such as releasing more often, or In this paper, we use three complementary methods to helping make changes (e.g., to merge pull requests) faster? study in-depth the usage of CI in open-source projects. To Are developers maximizing the usage of CI? Despite the understand what CI systems developers use, we analyzed widespread popularity of CI, we have very little quantita- 34,544 open-source projects from GitHub.
    [Show full text]
  • Rubinius Rubini Us Rubini.Us Rubini.Us Rubini.Us Rubinius History and Design Goals
    Rubinius Rubini us Rubini.us rubini.us http:// rubini.us Rubinius http://godfat.org/slide/2008-12-21-rubinius.pdf History and Design Goals Architecture and Object Model History and Design Goals Architecture and Object Model Evan Phoenix February of 2006 RubySpec MSpec Engine Yard C VM Shotgun C VM Shotgun C++ VM CxxTest LLVM History and Design Goals Architecture and Object Model Reliable, Rock Solid Code Reliable, Rock Solid Code Full Test Coverage 健康 Clean, Readable Code Clean, Readable Code Little Lines in Each File Clean, Readable Code Macro, Code Generator, Rake Task Clean, Readable Code CMake Clean, Readable Code CMake Clean, Readable Code C++ Object to Ruby Object 1 to 1 Mapping 清新 健康 清新 Modern Techniques Modern Techniques Pluggable Garbage Collectors Modern Techniques Pluggable Garbage Collectors • Stop-and-Copy Modern Techniques Pluggable Garbage Collectors • Stop-and-Copy • Mark-and-Sweep Modern Techniques Optimizers Modern Techniques Git, Rake, LLVM Squeak the Smalltalk-80 Implementation Squeak Slang Squeak • Alan Kay • Dan Ingalls • Adele Goldberg Smalltalk Xerox PARC Smalltalk Object-Oriented (differ from Simula and C++) Smalltalk GUI Smalltalk MVC History and Design Goals Architecture and Object Model Real Machine C++ Virtual Machine Real Machine kernel/bootstrap C++ Virtual Machine Real Machine kernel/platform kernel/bootstrap C++ Virtual Machine Real Machine kernel/common kernel/platform kernel/bootstrap C++ Virtual Machine Real Machine kernel/delta kernel/common kernel/platform kernel/bootstrap C++ Virtual Machine Real
    [Show full text]
  • Ruby on Rails
    Ruby.learn{ |stuff| } ● What is Ruby? ● What features make it interesting to me (and maybe you)? ● A quick, idiosyncratic tour of the Ruby ecosphere. Tuesday Software Lunch Talk: March 4, 2008 What is it? ● a dynamic, object-oriented, open source programming language... ● with a uniquely (but not too uniquely), expressive syntax ● dynamically or “duck” typed ● influenced by Perl, Smalltalk, Eiffel, Ada and Lisp ● has aspects of functional and imperative programming styles History ● created by Yukihiro “Matz” Matsumoto on Feb 24 1993, released to public in 1995 ● “Ruby” coined in comparison to “Perl” Philosophy (the “Ruby Way”) ● emphasize programmer needs over computer needs ● encourage good design, good APIs ● Principle of Least Surprise (POLS) – the language should behave in such a way as to minimize confusion for experienced users ● “Everything should be a simple as possible, but no simpler.” - Einstein ● orthogonality ● change at runtime is not to be feared Interesting Stuff... ● Is Not a Ruby tutorial – http://tryruby.hobix.com/ – Programming Ruby: The Pragmatic Programmer's Guide – our just google it – you want something totally different? ● http://poignantguide.net/ruby/ ● Is what I find interesting/different/well done about Ruby. Everything's an Object ● no exceptions Falsiness ● only false and nil are falsey. Not 0. Symbols ● labels ● lightweight strings with no behaviour ● often used as hash keys Blocks ● another name for a Ruby block is a “closure” ● clo-sure [kloh-zher] – noun. A function that is evaluated in an environment containing one or more bound variables. Procs ● anonymous subroutines or closures with a life of their own Adding Methods to Classes ● You can add methods to an object at runtime in several ways..
    [Show full text]
  • Conflict Resolution Via Containerless Filesystem Virtualization
    Dependency Heaven: Conflict Resolution via Containerless Filesystem Virtualization Anonymous Author(s) Abstract previous installation, effectively preventing concurrent ver- Resolving dependency versioning conflicts in applications sions of that library from coexisting. The same is true for is a long-standing problem in software development and packages whose executable names does not change across deployment. Containers have become a popular way to ad- releases; unless the user renames the existing executable dress this problem, allowing programs to be distributed in a files prior to the installation of a new version it is notpos- portable fashion and to run them under strict security con- sible to keep both installations around. The problem with straints. Due to the popularity of this approach, its use has that approach is that it breaks package managers, as the re- started to extend beyond its original aim, with users often named files will not be featured in the package manager’s creating containers bundling entire Linux distributions to database and, consequently, will not be tracked anymore. run mundane executables, incurring hidden performance Further, unless executables depending on the renamed files and maintenance costs. This paper presents an alternative are modified to reflect their new path, users need todefine approach to the problem of versioning resolution applied to which executable to activate at a given time, usually through locally-installed applications, through a virtualization tool tricky management of symbolic
    [Show full text]
  • Spice Program Open Source 2015 Learnings
    Spice Program Open Source 2015 learnings Please see this Futurice Spice Program blog post to learn the context for this list. ​ ​ Learned even more about practical problems in measuring time. Direct uploads from browser to AWS S3. Basics of Polymer. React + Redux (lots of it). Basic info about Google Cloud Services. Practical usage of Google Cloud Storage (the Google's S3 equivalent). Heroku Pipelines. Improved & more modular Angular application structure formation. Webpack, JSON Web Token implementation on the backend, and ES6. Actually learning how Promises should be used in JavaScript. Some knowledge about Dokku, the host­it­yourself­Heroku. Got practical experience and more understanding about Node.js, npm, and bacon.js. How the Azure Web App continuous deployment works. A bit on how Travis CI operates under the hood. How to make Joomla templates. Learned about Let's Encrypt on Apache with vhosts. Learned more about Web MIDI API and RxJS. Also more about ES6 and setting up a compact development environment for that. Learned basics of RxJS. Learned a lot about creating a reusable library with JS/browserify. Learned some Cycle.js. Learned a little about Node.js testing. Learned the EMV chip card specification on very detailed level by implementing large part of the specification. I'm using the EMV knowledge on daily basis in my current client project. Improved my Clojure language skills. Learned to work with the Go programming language. Wrote an OSS tool that I later then used in a customer project. I learned better ways to use Dagger 2 in Android and trial and evaluate other app architectural patterns based around this.
    [Show full text]
  • Open Source Best Practices: from Continuous Integration to Static Linters
    THE MOLECULAR SCIENCES SOFTWARE INSTITUTE - LOGO CONCEPTS ROUND 2 Open Source Best Practices: From Continuous Integration to Static Linters Daniel G. A. Smith and Ben Pritchard The Molecular Sciences Software Institute !1 @dga_smith / @molssi_nsf 1. 3 The Molecular Sciences Software Institute (MolSSI) •Designed to serve and enhance the software development efforts of the broad field of computational molecular science (CMS). •Funded at the institute level under the Software Infrastructure for Sustained Innovation (SI2) initiative by the National Science Foundation. •Launched August 1st, 2016 •Collaborative effort by: •Virginia Tech •U.C. Berkeley •U. Southern •Rice U. •Stanford U. California •Stony Brook U. •Rutgers U. •Iowa State U. !2 The Molecular Sciences Software Institute (MolSSI) •Software Infrastructure •Build open-source frameworks and packages for the entire CMS community •Education and training •Online materials and training guides •Host a number of targeted workshops, summer schools, and other training programs •Community Engagement and Leadership •Interoperability standards and best practices !3 •Data and API standardization targets Talk Motivation •Many terms thrown around: •Best Practice •Manage Code •DevOps •Build and Package •Open Source •“Just get the physics •Software Sustainability working” •“Incorrect Software” “Best” is subjective and depends on your own community. Lets discuss practical applications and how to make our lives easier! !4 Open Source Open Source software is software that can be freely accessed, used,
    [Show full text]
  • Jruby: Enterprise
    JRuby Enterprise 2.0 James Crisp Josh Price ThoughtWorks Agenda • What are Ruby and JRuby? • Benefits and Drawbacks • Where to use? • Demos • Case studies Ruby • Created by Yukihiro Matsumoto in 1993 • Open Source • Vibrant community • Dynamically typed • Pure OO • Syntactically flexible for DSLs • Advanced meta programming Ruby Runtimes • MRI Matz’s Ruby Interpreter in C (Ruby 1.8.6) • YARV Yet another Ruby VM (Ruby 1.9) • IronRuby .NET, DLR (alpha) • Rubinius Alternative VM • xRuby Compiler in Java • JRuby on the JVM Java platform Today’s Java Platform JRuby • Java implementation of Ruby • Open Source • Full time developers from Sun and ThoughtWorks • Charles Nutter, Thomas Enebo, Ola Bini et al • Allows Ruby to call Java code and vice versa Timeline • Started around 2001 by Jan Arne Petersen • JRuby 1.0 released in June 2007 • JRuby 1.1 RC2 just released • 1.1 release out soon Why JRuby? • Ruby / Rails productivity & tools • Java libraries and interoperability • Run on any OS / JVM / App server • Leverage existing infrastructure & ops skills • Politics – it's just a WAR JRuby advantages • Native vs Green Threading • World class garbage collection • Unicode • Runs the same on all platforms • JIT & AOT compilation JRuby disadvantages • Large memory footprint • Longer startup times • No native C extensions • Not technically complete Ruby Demo A Simple Ruby Class class RubyDemo < Demo def say_hello 5.times { puts “Hi from Ruby!” } end def greet(guests) guests.collect { |g| “Welcome #{g.name}” } end end >> RubyDemo.new.greet(josh, james)
    [Show full text]