Grooscript in Action SpringOne2gx 2015

Unless otherwise indicated, these slides are © 2013-2015 Pivotal Software, Inc. and licensed under a Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/
SPRINGONE2GX
WASHINGTON, DC
Grooscript in Action
By Jorge Franco Leza
@jfrancoleza

Unless otherwise indicated, these slides are © 2013-2015 Pivotal Software, Inc. and licensed under a 
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/
About me
2
Developer
jorge.franco.leza@gmail.com

Thank you!
3
3 years since first commit

Agenda
• Introduction to grooscript
• Convert your groovy code to javascript
• Support
• PhantomJs and tools
• Gradle plugin
• Demo
• Grails plugin
• Working with javascript
• Require.js
• Future
4

Introduction to grooscript
• Library (jar)
• Groovy 2.0+ to javascript ECMA 5
• Apache 2 license
• Source code http://github.com/chiquitinxx/grooscript
• Converted code needs grooscript.js to run
• Tools around: gradle and grails plugins, npm and bower packages
• Documentation http://grooscript.org/doc.html
• Demos http://github.com/chiquitinxx/grooscript-demos
• Try live! http://grooscript.org/conversions.html
5

Why grooscript?
• You have all java / groovy tools to create code in the client side.
• Javascript is fast.
• Enjoy javascript! Create your own magic.
• Don’t repeat code in two languages, isomorphic code.
• Use groovy templates everywhere.
• Single development environment.
• Stop learning “to javascript” things.
• Static type if you want to.
• But… mainly… because it is…
6

Groovy
7
Readable
Concise
Expressive

ASTS
8
@Component 
class Counter implements Colorable { 
 
Integer number 
 
void init() { 
number = null 
} 
 
void render() { 
div(class: "widget bg-${randomColor()}") { 
if (number) { 
p 'Number of books' 
em number.toString() 
a(href:"#", class:"button",
onclick: 'bookPresenter.showBooks()') { 
yield 'Show' 
} 
} else { 
p 'Counting books...' 
} 
} 
} 
}
AST’s
Getter / Setters

List and maps
9
def start() {
def countries = loadCountries().
findAll { it.population > 100000}.
unique { it.alpha3Code }
countries.each { country ->
customSigma.addNode id: country.alpha3Code,
x: country.latlng[1], color: ‘purple’
}
countries.each { country ->
country.borders?.each { border ->
this.&hello(border)
}
}
updateNumberCountries countries.size()
customSigma.refresh()
}
Lists and maps

DSL's
10
server {
get('/') {
render Templates.applyTemplate('index.gtpl')
}
on('login') { data, socket ->
if (data.name && !socket.login) {
socket.login = data.name
socket.emit 'loginok', [name: data.name]
socket.broadcast.emit 'loginok', [name: data.name]
}
}
on('msg') { data, socket ->
if (data.msg && socket.login) {
socket.broadcast.emit 'msg', [msg: data.msg]
}
}
on('disconnect') { socket ->
if (socket.login) {
socket.broadcast.emit 'off', [name: socket.login]
}
}
}.start()
Dsl’s

Metaprogramming
11
class Hello {
def methodMissing(String name, args) {
println "Hello ${name}!"
}
}
def hello = new Hello()
hello.Groovy()
hello.Javascript()
hello.grooscript()
Metaprogramming

Functional
12
def plus2 = { it + 2 }
def times3 = { it * 3 }
def times3plus2 = plus2 << times3
assert times3plus2(3) == 11
def plus2times3 = times3 << plus2
assert plus2times3.curry(5)() == 21
Functional

Convert your groovy code to javascript
13
@Grab('org.grooscript:grooscript:1.2.0')
import org.grooscript.GrooScript
String result = GrooScript.convert '''
def sayHello = { println "Hello ${it}!" }
['Groovy','JavaScript','GrooScript'].each sayHello
'''
new File(‘out.js’) << result

Convert your groovy code to javascript
14
Let’s see it in action
http://grooscript.org/doc.html

Conversion options
• classpath
• customization { -> ast(TypeChecked)}
• initialText, finalText
• recursive
• mainContextScope [''$'', ‘'window'', ''myFunction'']
• addGsLib
• requireJsModule
• consoleInfo
• includeDependencies
15

Support
• Groovy core
• Classes, numbers, lists, maps, sets, date, ranges, closures, (g)strings, operators,
groovy truth, Expando, categories, traits, beans, switch, metaprogramming,
enum, equals, multiple assignment, optional params, default constructor, pointer
methods, operator overload, regular expressions, @Delegate, @Category, …
• Dsl’s. (@DelegatesTo)
• Ast’s at semantic analysis phase.
• Packaging in js with require.js.
• Be groovier!
16

Not supported
• Not groovy-core (json, builders, I/O, …)
• Java / Groovy Types (Thread, LinkedHashMap, Stack, Optional, …)
• Super except constructors.
• Methods with same name (overload), classes with same name.
• Java 8 stuff not supported by groovy
• Module extensions, complex metaprogramming, groovy AST’s after Semantic
Phase
17

Annotations
18
import org.grooscript.asts.GsNotConvert
@GsNotConvert
class ClassNotConvert {
def a
}
class A {
@GsNotConvert
def methodNoConvert() {
‘No!’
}
def hello() {
println ‘Hello!’
}
}
import org.grooscript.asts.GsNative
class Data {
@GsNative
void saySomething(String smt) {/*
console.log(smt);
*/}
@GsNative
def five() {/*
return 5;
*/ 1 + 1 + 3
}
}

PhantomJs test
19
@GrabConfig(systemClassLoader = true)
@Grab(‘org.grooscript:grooscript:1.2.0’)
import org.grooscript.asts.PhantomJsTest
//Need phantomjs installed
System.setProperty(‘PHANTOMJS_HOME’, ‘path/to/phantomjs’)
@PhantomJsTest(url = 'http://beta.groovy-lang.org/')
void testCountLinks() {
def links = $('a')
assert links.size() > 40, "Number of links: ${links.size()}"
links.toArray().collect { it.toString() }.each { link ->
println link
}
}
testCountLinks()

Javascript libs
• grooscript.js (87 kb) (8 kb minified and gziped)
• grooscript.min.js (33 kb)
• grooscript-tools.js (14 kb) (GQuery, HtmlBuilder, Observable)
20

HtmlBuilder
21
given:
def result = HtmlBuilder.build {
body {
ul(class: 'list', id: 'mainList') {
2.times { number ->
li number + 'Hello!'
}
}
}
}
expect:
result == "<body><ul class='list' id=‘mainList'>
<li>0Hello!</li><li>1Hello!</li></ul></body>"

GQuery
22
import org.grooscript.jquery.GQueryImpl
def result = new Result()
def gQuery = new GQueryImpl()
gQuery.onReady {
gQuery.doRemoteCall(“${JSON_ADDRESS}”, 'GET', null, { res ->
gQuery('.result').html('OK')
result = res
}, {
result = 'FAIL!'
}, Result)
}
https://github.com/chiquitinxx/grooscript/blob/master/src/
main/groovy/org/grooscript/jquery/GQuery.groovy

Observable
23
given:
def result = []
Observable.from([1, 5, 9, 12, 3, 8]).
filter { it < 5 }.
map { 'H' * it }.
subscribe { event ->
result << event
}
expect:
result == ['H', 'HHH']
https://github.com/chiquitinxx/grooscript/blob/master/src/
test/groovy/org/grooscript/rx/ObservableSpec.groovy

Gradle plugin
• Starting guide http://grooscript.org/starting_gradle.html
• Listen to changes and does conversions in background.
• Groovy templates in the client side.
• Can use with your grails 3+ application.
• Create require.js modules.
• Notification of changes using websockets.
• Thread tasks can block execution.
• Info about tasks http://grooscript.org/gradle/tasks.html
24

task convert
Convert groovy files to javascript. Can add conversion options.
25
grooscript {
source = ['src/main/groovy']
destination = 'js'
}

Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/ 26
task convertThread
grooscript {
source = [‘src/main/groovy/presenters']
destination = 'js'
classpath = ['src/groovy']
initialText = '//Converted file'
recursive = true
blockExecution = true
}
Listen to changes in groovy files, and convert them to javascript when modified. Can
block gradle execution.

task initStaticWeb
"## build.gradle
$## src
$## main
"## groovy
% $## Presenter.groovy
$## webapp
"## index.html
$## js
"## app
$## lib
"## grooscript-tools.js
"## grooscript.min.js
$## jquery.min.js
Creates a static web project to starting play with grooscript.

task templatesJs
class Templates {
static Map<String, Closure> templates
static String applyTemplate(String name, model = [:]) {
Closure cl = templates[name]
cl.delegate = model
cl(model)
}
}
Convert groovy templates to a javascript file.

task templatesThread
templates {
templatesPath = 'templates'
templates = ['main.gtpl', 'little/small.tpl']
destinationFile = 'js/Templates.js'
classpath = ['src/groovy']
customTypeChecker = 'aCustomTypeCheckerFile.groovy'
}
Listen to changes in groovy templates and generate a new javascript template file
when something changes. Can block gradle execution.

task spyChanges
spy {
files = ['Templates.js']
onChanges = { list ->
springWebsocketTo 'http://localhost:8080/demo' data
'templates' onChannel '/app/reload'
}
}
Listen to file changes and execute groovy code when files change. Can send a
message using websockets.

task requireJs
requireJs {
sourceFile = 'src/main/groovy/MyApp.groovy'
destinationFolder = 'src/main/resources/web/js/app'
}
Convert groovy file to require.js javascript module. Also all dependencies are
converted.

task requireJsThread
32
requireJs {
sourceFile = ‘starting/InitialFile.groovy'
classpath = ['src/main/groovy']
destinationFolder = ‘js/app'
blockExecution = true
}
Listen to changes in groovy file or any dependency file, and generate require.js
javascript modules when files change. Also can block execution.

Demo gradle books
More action
https://github.com/chiquitinxx/books-demo

Grails plugin
• A grails 2 version, 0.8 https://grails.org/plugin/grooscript.
• Grails 3 version, version 1.1.2, documentation http://grooscript.org/grails3-plugin.
• Adding tags for your gsp’s.
• Converting files with gradle plugin in grails 3+.
• Using your domain classes in your gsp’s. *experimental*
• Uses asset pipeline and cache plugins, also jquery for some tags.
• Requires <asset:javascript src="grooscript-grails.js"/>
• Events in your gsp's with groovy.
• Websockets support using spring websockets.
• Templating in your gsp’s with HtmlBuilder.
34

grooscript:code
35
<grooscript:code>
[‘groovy’, ‘javascript’].each {
println “Hello $it”
}
</grooscript:code>
<asset:script>
… js code …
</asset:script>

grooscript:template
36
<grooscript:template onLoad=“false" functionName=“refreshList">
ul {
data.each { book ->
li {
p 'Id: ' + book.id + ' Name: ' + book.title
}
}
}
</grooscript:template>

websockets
37
<grooscript:initSpringWebsocket>
println 'Connected! Websocket is up!’
GrooscriptGrails.sendWebsocketMessage("/app/hello", “Hello!")
</grooscript:initSpringWebsocket>
<grooscript:onServerEvent path="/topic/books" type="Book">
data.each { book ->
$("#helloDiv").append '<p>'+book.coolFormat()+'</p>'
}
</grooscript:onServerEvent>
Use spring websockets in your gsp’s. Have to include client libraries.

events
38
<grooscript:code>
$(document).ready {
def eventData = 'Application started.'
gsEvents.sendMessage('newEvent', eventData)
gsEvents.onEvent('delete', { book ->
$('#deleteEvent').html 'Deleted ' + book.title
})
}
</grooscript:code>
<grooscript:onEvent name="newEvent">
console.log event
</grooscript:onEvent>
Manage events in the client using groovy.

grooscript:remoteModel
39
<grooscript:remoteModel domainClass="Book"/>
<grooscript:code>
import rest.Book
Book.list().then { list ->
$('#bookList').html ''
list.each addBook
}
</grooscript:code>
Use your domain classes from your gsp’s. Domain classes annotated with
@Resource, using json.

Demo grails 3
40
Final action
https://github.com/chiquitinxx/circles

Working with javascript
41
class MyClass {} function MyClass() { … }
var myClass = MyClass();
// NO var myClass = new MyClass();
var myClass = MyClass({prop1: ‘value’, prop2: 12 });
myClass.method();
// NO myClass.metaprogrammingMethod();
myClass.method(numberOrStringOrList);
// beware maps! myClass.method({ a: 1, b: 2 });

Combine both worlds
42
import static org.grooscript.GrooScript.toJavascript
import static org.grooscript.GrooScript.toGroovy
def map = [x: 1, y: 2]
//point is a javascript object
point.init(map) //[BAD] Passing a groovy object to javascript, can fail
point.init(toJavascript(map)) //[GOOD] You now are passing {x: 1, y: 2}
//point has a method info() that returns a javascript object
def badData = point.info() //[BAD] You will have a 'javascript' object
def goodData = toGroovy(point.info()) //[GOOD] goodData as a 'groovy' object

Tips
• Keep your groovy code tested.
• If you use @GsNative, keep that code in isolated classes, that can be easy to
mock them.
• Don’t abuse @GsNative, is untested code.
• You can activate debug console info in javascript with gs.consoleInfo = true;
• You can test dom manipulation with jsoup.
• Try to stay functional, don’t abuse ‘this’ or variables from other contexts.
• Curry functions to inject variables rather than expecting them to be available
after callbacks hell.
43

Require.js
• Javascript file and module loader.
• Can be used in browser, rhino and Node.js environments.
• Optimization using google closure compiler.
44
requirejs.config({
baseUrl: 'jsModules',
paths: {
lib: 'js/lib'
}
});
requirejs(['lib/grooscript.min'], function() {
requirejs(['Initial']);
});

Require.js
45
import org.grooscript.GrooScript
Map conversionOptions = [classpath: 'src/main/groovy']
GrooScript.convertRequireJs('src/main/groovy/Initial.groovy',
'jsModules', conversionOptions)
define(function() {
function Initial() { … }
return Initial;
});
class Initial {
}
src/main/groovy/Initial.groovy jsModules/Initial.js

Require.js
46
define(['lib/data'], function (data) {
function Require() {
//..
gSobject.data = data;
//..
return gSobject;
};
return Require;
});
package files
import org.grooscript.asts.RequireJsModule
class Require {
@RequireJsModule(path = 'lib/data')
def data
}
src/main/groovy/files/Require.groovy jsModules/files/Require.js

Future
47
ECMAScript 2015

Q & A

Thank you!
49
Waiting for your feedback and questions from now to Thursday

Grooscript in Action SpringOne2gx 2015

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