Play framework

Play! frameworkPlay! framework

Sẩm Bảo Chung Web development with Play!

Agile web development.

Created by Guillaume Bort 2007

AgendaAgenda

OverviewMain Concept

Five cool things you can do with play Fix the bug and hit Reload Simple stateless MVC architecture Efficient template engine Test driven development Job

Play enviromentDiscuss


Play OverviewPlay OverviewPure Java

More productive Java environment!

Targets Restful architectures

No compile, deploy, restart cycle - Fix the bug and hit

reload!

Clean template system - using Groovy, Scala template

Exact errors (including line numbers, even for templates)

Lots of built-in features for fast development

Starts fast, runs fast

Extensible by modules

Sẩm Bảo Chung Web development with Play

Main ConceptMain Concept

Simple stateless MVC architecture

Five cool things you can do with play

Fix the bug and hit Reload

Efficient template engine

JPA

Test driven development

Job


Play architecture MVCPlay architecture MVCThe Play framework is fully stateless and only request/response-oriented

1.An HTTP Request is received by the framework.

2.The Router component tries to find the most specific route able to accept this request.

3.The corresponding action method is then invoked.

4.The application code is executed.5.If a complex view needs to be generated, a template file is rendered.

6.The result of the action method (HTTP Response code, Content) is then written as an HTTP Response.


Routes fileRoutes file

A routes file help play controller routine the request

GET / Ap p l i c a t i o n . i n d e xGET / u s e r /{ username } Ap p l i c a t i o n . showUserPOST / u s e r Ap p l i c a t i o n . c r e a t eUs e rDELETE / u s e r /{ username } Ap p l i c a t i o n . d e l e t eUs e rGET / p u b l i c s t a t i c D i r : p u b l i c


ModelModel

A simple user

@Entitypublic class User extends Model{

@Idpublic long id;

@Required@Column(unique = true)public String username;

@Required@Emailpublic String email;

}


ControllerController

UserControllerpublic class Application extends Controller {

public static void index() {List<User> users = User.findAll();render(users);}

public static void showUser(String username) {User user = User.find("byUsername",

username).first();notFoundIfNull(user);render(user);

}


ViewView

List users (app/views/Application/index.html)#{ extends ’main .html ’ /}#{ set title :’Index ’ /}<ul >#{ list items :users , as:’user ’}

<li >#{a @Application . showUser ( user . username )}

${ user . username }#{/ a}with email address ${ user . email }</li >

#{/ list }</ul >


Five cool things of Play!

Bind an HTTP parameter to a Java method parameter

Redirect to an action by calling the corresponding Java method

render(…) , renderText(…), renderXML(…), renderJSON(…), renderBinary(…), redirect(…)



Don’t Repeat Yourself when passing Java objects to templatesPlay will automatically start the JPA Entity Manager using Hibernate and magically synchronize it when code is reloaded.



Straightforward file upload management

#{form @uploadPhoto(), enctype:'multipart/form-data'} <input type="text" name="title" /> <input type="file" id="photo" name="photo" /> <input type="submit" value="Send it..." /> #{/}

public static void uploadPhoto(String title, File photo) { ... }


Fix the bug and hit Fix the bug and hit ReloadReload

Whenever an error occurs, the framework makes its best effort to identify and show you the problem


JobJob Doing the right thing at the right time• Scheduled jobs (housekeeping)• Bootstrap jobs (initial data providing)• Suspendable requests (rendering a PDF

report without blocking the• connection thread pool)

/* @Every("1h") */@OnApplicationStartpublic class LoadDataJob extends Job {

public void doJob() {/* .. do whatever you want */}

}


Test driven development The integrated test runner makes it easy for you do test-

driven development.


Getting startGetting start

Using the play commandWhen the framework is correctly installed, open a shell and execute play.$ play You should see the play default message.



Use the new command to create a new application. # play new myApp



You can start with command# play run myApp


ModulesModulesSome module on http://www.playframework.org/modulesWith:ScalaGoogle App EnginePDF GenerationSASS and SCSSGoogle Web ToolkitMongoDBSimple searchObjectifyTo install locally these modules use the install command:play install gae-{version}To add this module as dependency of your application, add it to the dependencies.yml file:require: - play -> gae {version}.


Play framework

Design

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