学习 play! 框架（Part One）

Creating a new application

$ activator new my-first-app play-java	
or
$ activator new								# prompt

The standard application layout

app                    		-> Application sources
 └ assets              -> Compiled asset sources
	└ stylesheets	-> Typically LESS CSS sources
	└ javascripts    	-> Typically CoffeeScript sources
 └ controllers     	      	-> Application controllers
	└ Application.java
 └ models          		-> Application business layer
 └ views            	-> Templates
	└ index.scala.html
	└ main.scala.html
 └ utils			-> add your own packages here
build.sbt          -> Application build script
conf         	-> Configurations files and other non-compiled resources (on classpath)
 └ application.conf    	  	-> Main configuration file
 └ routes                		-> Routes definition
public                   	-> Public assets
 └ stylesheets           		-> CSS files
 └ javascripts           		-> Javascript files
 └ images                		-> Image files
project              	-> sbt configuration files
 └ build.properties  	    	-> Marker for sbt project
 └ plugins.sbt           		-> sbt plugins including the declaration for Play itself
lib                      	-> Unmanaged libraries dependencies
logs                     	-> Standard logs folder
 └ application.log       		-> Default log file
target                   	-> Generated stuff
 └ scala-2.10.0            	
	└ cache              	
	└ classes         		-> Compiled class files
	└ classes_managed 		-> Managed class files (templates, ...)
	└ resource_managed		-> Managed resources (less, ...)
	└ src_managed      		-> Generated sources (templates, ...)
test                     	-> source folder for unit or functional tests
 └ ApplicationTest.java
 └ IntegrationTest.java

app/controllers/Application.java

public class Application extends Controller {
    public static Result index() {
        return ok(index.render("Your new application is ready."));
    }
}

conf/routes

Home page
GET / controllers.Application.index()
Map static resources from the /public folder to the /assets URL path
GET /assets/*file controllers.Assets.at(path=”/public”, file)

another

public static Result hello(String name) {
	return ok(views.html.hello.render(name));
}

$ console
scala> views.html.hello.render("Play!")

A basic CRUD application example

conf/routes

GET / controllers.Products.index()
GET /products/ controllers.Products.list()
GET /products/new controllers.Products.newProduct()
GET /products/:ean controllers.Products.details(ean: String)
GET /product/$ean<[0-9]{13}> controllers.Products.details(ean: Long)
POST /products/ controllers.Products.save()

---

GET /products/:page controllers.Products.list(page:Int) http://localhost/products/2
GET /products/ controllers.Products.list(page:Int) http://localhost/products/?page=2

---

Route with default value
GET /products controllers.Products.list(page:Int ?= 0)
Fixed value as parameter
GET / controllers.Products.list(page: Int = 0)

app/controllers/Products.java

public class Products extends Controller {
	public static Result index() {
		return redirect(routes.Products.list(0));
	}
	public static Result list(Integer page) {	...	}
	public static Result list() {									// List all products
		List<Product> products = Product.findAll();
		return ok(list.render(products));
	}
	public static Result newProduct() {						// Show a blank product form
		return ok(details.render(productForm));
	}
	public static Result delete(String ean) {  ...  }
	public static Result details(String ean) {		// Show a product edit form
		return TODO;		// return badRequest("Incorrect EAN: " + ean);  return notFound("No product with EAN " + ean);
	}
	public static Result save() {									// Save a product
		...
	}
}

/app/models/Product.java

package models;
public class Product {
	private static List<Product> products;
	static {
		products = new ArrayList<Product>();
		products.add(new Product("1111111111111", "Paperclips 1",
									"Paperclips description 1"));
		...
	}
	public String ean;
	public String name;
	public String description;
	public Product() {}
	public Product(String ean, String name, String description) {
		this.ean = ean;
		...
	}
	public static Product findByEan(String ean) {
		for (Product candidate : products) {
			if (candidate.ean.equals(ean)) {	return candidate;  }
		}
		return null;
	}
	public static List<Product> findByName(String term) {
		final List<Product> results = new ArrayList<Product>();
		for (Product candidate : products) {
			if (candidate.name.toLowerCase().contains(term.toLowerCase())) {
				results.add(candidate);
			}
		}
		return results;
	}
	public static boolean remove(Product product) {return products.remove(product);}
	public void save() {
		products.remove(findByEan(this.ean));
		products.add(this);
	}
}

/app/views/products/list.scala.html

@(products: List[Product])
@main("Products catalogue") {
	<h2>All products</h2>
	<script>
		function del(urlToDelete) {
			$.ajax({
				url: urlToDelete,
				type: 'DELETE',
				success: function(results) {		// Refresh the page
					location.reload();
				}
			});
		}
	</script>
	<table class="table table-striped">
	  <thead>
	  <tr>
		<th>EAN</th> <th>Name</th> <th>Description</th>
	  </tr>
	  </thead>
	  <tbody> @for(product <- products) {
	  	<tr>
	  	  <td><a href="@routes.Products.details(product.ean)">@product.ean</a></td>
		  <td><a href="@routes.Products.details(product.ean)">@product.name</a></td>
		  <td><a href="@routes.Products.details(product.ean)">@product.name</a></td>
	  	</tr>
	  } </tbody>
	</table>
	<a href="@routes.Products.newProduct()" class="btn">
		<i class="icon-plus"></i> New product</a>
}

/app/views/products/details.scala.html

@(productForm: Form[Product])
@import helper._
@import helper.twitterBootstrap._
@main("Product form") {
	<h1>Product form</h1>
	@helper.form(action = routes.Products.save()) {
	  <fieldset><legend>Product (@productForm("name").valueOr("New"))</legend>
		@helper.inputText(productForm("ean"), '_label -> "EAN")
		@helper.inputText(productForm("name"),'_label -> "Name")
		@helper.textarea(productForm("description"), '_label -> "Description")
	  </fieldset>
	  <input type="submit" class="btn btn-primary" value="Save">
	  <a class="btn" href="@routes.Products.index()">Cancel</a>
	}
}