Matt RaibleMatt Raible is a writer with a passion for software. Connect with him on LinkedIn.

The Angular Mini-Book The Angular Mini-Book is a guide to getting started with Angular. You'll learn how to develop a bare-bones application, test it, and deploy it. Then you'll move on to adding Bootstrap, Angular Material, continuous integration, and authentication.

Spring Boot is a popular framework for building REST APIs. You'll learn how to integrate Angular with Spring Boot and use security best practices like HTTPS and a content security policy.

For book updates, follow @angular_book on Twitter.

The JHipster Mini-Book The JHipster Mini-Book is a guide to getting started with hip technologies today: Angular, Bootstrap, and Spring Boot. All of these frameworks are wrapped up in an easy-to-use project called JHipster.

This book shows you how to build an app with JHipster, and guides you through the plethora of tools, techniques and options you can use. Furthermore, it explains the UI and API building blocks so you understand the underpinnings of your great application.

For book updates, follow @jhipster-book on Twitter.

10+ YEARS


Over 10 years ago, I wrote my first blog post. Since then, I've authored books, had kids, traveled the world, found Trish and blogged about it all.

Integrating HTML5 Boilerplate with Scalate and Play

HTML5 Boilerplate is a project that provides a number of basic files to help you build an HTML5 application. At its core, it's an HTML template that puts CSS at the top, JavaScript at the bottom, installs Chrome Frame for IE6 users and leverages Modernizr for legacy browser support. It also includes jQuery with the download. One of the major benefits of HTML5 Boilerplate is it ships with a build system (powered by Ant) that concatenates and minimizes CSS and JS for maximum performance. From html5boilerplate.com:

Boilerplate is not a framework, nor does it prescribe any philosophy of development, it's just got some tricks to get your project off the ground quickly and right-footed.

I like the idea of its build system to minify and gzip, but I'd probably only use it if I was working on a project that uses Ant. Since I'm using it in a Play project, the whole Ant build system doesn't help me. Besides, I prefer something like wro4j. Wro4j allows you to specify a group of files and then it compiles, minimizes and gzips them all on-the-fly. As far as I know, Play doesn't have any support for Servlet Filters, so using wro4j in Play is not trivial.

The good news is Play has a GreenScript module that contains much of the wro4j functionality. However, since I'm using Scalate in my project, this goodness is unavailable to me. In the future, the Scalate Team is considering adding better wro4j, JavaScript and CSS integration. In the meantime, I'm going to pretend I don't care about concatenation and minimization and trundle along without this feature.

To add HTML5 Boilerplate to my Play project, I performed the following steps:

  • Downloaded the 2.0 Zipball.
  • Copied all the static files to my project. Below are the commands I used (where $boilerplate-download is the expanded download directory and ~/dev/play-more is my project):
    cd $boilerplate-download
    cp 404.html ~/dev/play-more/app/views/errors/404.html
    cp *.png ~/dev/play-more/public/.
    cp crossdomain.xml ~/dev/play-more/public/.
    cp -r css ~/dev/play-more/public/stylesheets/.
    cp favicon.ico ~/dev/play-more/public/.
    cp humans.txt ~/dev/play-more/public/.
    cp -r js/libs ~/dev/play-more/public/javascripts/.
    cp robots.txt ~/dev/play-more/public/.
    
  • Copied the index.html to ~/dev/play-more/app/templates/layouts/default.jade and modified it to use Jade syntax. Since I downloaded the comments-heavy version, I modified many of them to be hidden in the final output.
    -@ val body: String 
    -@ var title: String = "Play More"
    -@ var header: String = ""
    -@ var footer: String = ""
    !!! 5
    / paulirish.com/2008/conditional-stylesheets-vs-css-hacks-answer-neither/ 
    <!--[if lt IE 7]> <html class="no-js ie6 oldie" lang="en"> <![endif]-->
    <!--[if IE 7]>    <html class="no-js ie7 oldie" lang="en"> <![endif]-->
    <!--[if IE 8]>    <html class="no-js ie8 oldie" lang="en"> <![endif]-->
    -# Consider adding an manifest.appcache: h5bp.com/d/Offline 
    <!--[if gt IE 8]><!--> <html class="no-js" lang="en"> <!--<![endif]-->
    head
      meta(charset="utf-8")
    
      -# Use the .htaccess and remove these lines to avoid edge case issues. More info: h5bp.com/b/378 
      meta(http-equiv="X-UA-Compatible" content="IE=edge,chrome=1")
    
      title=title
      meta(name="description" content="")
      meta(name="author" content="Matt Raible ~ [email protected]")
    
      -# Mobile viewport optimized: j.mp/bplateviewport 
      meta(name="viewport" content="width=device-width,initial-scale=1")
    
      -# Place favicon.ico and apple-touch-icon.png in the root directory: mathiasbynens.be/notes/touch-icons
    
      -# CSS: implied media=all
      link(rel="stylesheet" href={uri("/public/stylesheets/style.css")})
      -# end CSS
    
      -# More ideas for your <head> here: h5bp.com/d/head-Tips 
      -#
        All JavaScript at the bottom, except for Modernizr / Respond.
        Modernizr enables HTML5 elements & feature detects; Respond is a polyfill for min/max-width CSS3 Media Queries
        For optimal performance, use a custom Modernizr build: www.modernizr.com/download/ 
    
      script(type="text/javascript" src={uri("/public/javascripts/libs/modernizr-2.0.6.min.js")})
    body
      #container
        header = header
        #main(role="main")
          != body
        footer = footer
    
      -# JavaScript at the bottom for fast page loading 
      
      / Grab Google CDN's jQuery, with a protocol relative URL; fall back to local if offline 
      script(type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js")
      :javascript
        window.jQuery || document.write('<script src={uri("/public/javascripts/libs/jquery-1.6.2.min.js")}><\/script>')
    
      -# Change UA-XXXXX-X to be your site's ID 
      :javascript
        window._gaq = [['_setAccount','UA-25859875-1'],['_trackPageview'],['_trackPageLoadTime']];
        Modernizr.load({
          load: ('https:' == location.protocol ? '//ssl' : '//www') + '.google-analytics.com/ga.js'
        });
    
      -# Prompt IE 6 users to install Chrome Frame. Remove this if you want to support IE 6. 
      -# http://chromium.org/developers/how-tos/chrome-frame-getting-started 
      /[if lt IE 7]
        script(src="//ajax.googleapis.com/ajax/libs/chrome-frame/1.0.3/CFInstall.min.js")
        :javascript
          window.attachEvent('onload',function(){CFInstall.check({mode:'overlay'})})
            
    != "</html>"
    
  • Next, I had to add support for layouts to my homegrown Scalate support. I did this by specifying a layoutStrategy when initializing the TemplateEngine. From play-more/app/controllers/ScalateTemplate.scala:
    engine.classLoader = Play.classloader
    engine.layoutStrategy = new DefaultLayoutStrategy(engine, 
      Play.getFile("/app/templates/layouts/default" + scalateType).getAbsolutePath)
    engine
    

That's it! Now I have HTML5 Boilerplate integrated into my Play/Scalate/Jade application. To set the title and header in my index.jade, I simply added the following lines at the top:

- attributes("title") = "Counting"
- attributes("header") = "HTML5 Rocks!"

CoffeeScript Tip
Yesterday, I mentioned that I was having issues getting CoffeeScript to work with Scalate and that I was going to try and get the in-browser compiler working. First of all, reverting to Scalate 1.4.1 didn't work because there is no CoffeeScript support in 1.4.1. So I stayed with 1.5.2 and used PandaWood's Running CoffeeScript In-Browser Tutorial. I copied coffee-script.js to ~/dev/play-more/public/javascripts/libs and added a reference to it in my default.jade layout:

-# JavaScript at the bottom for fast page loading 
script(type="text/javascript" src={uri("/public/javascripts/libs/coffee-script.js")})

Then I was able to write CoffeeScript in a .jade template using the following syntax:

:plain
  <script type="text/coffeescript">
    alert "hello world"
  </script>

Summary
If you've integrated HTML5 Boilerplate into your Play application, I'd love to hear about it. Now that I have all the infrastructure in place (Jade, CoffeeScript, HTML5 Boilerplate), I'm looking forward to getting some development done. Who knows, maybe I'll even come up with my own Play Un-Features That Really Irk My Inner Geek.

Posted in Java at Sep 28 2011, 08:49:35 AM MDT 2 Comments

Trying to make CoffeeScript work with Scalate and Play

A few weeks ago, I wrote about integrating Scalate with Play.

The next steps in my Play Scala adventure will be trying to get the CoffeeScript module to work. I also hope to integrate HTML5 Boilerplate with Jade and Scalate Layouts.

Since my last writing, the Scalate Team has created a new branch for Scala 2.8.x (that's compatible with Play) and released 1.5.2. To upgrade my Play application to use this version, I changed my dependencies.yml to have the following:

  - org.fusesource.scalate -> scalate-core 1.5.2-scala_2.8.1:
      transitive: false
  - org.fusesource.scalate -> scalate-util 1.5.2-scala_2.8.1:
      transitive: false

Unfortunately, this release breaks Scalate's CoffeeScript support because it wraps the code with illegal comments. This has been fixed in the latest snapshot, but no new release has been cut. However, even if it did work, it's not quite what I'm looking for. The 1.5.2 release allows for compiling inline CoffeeScript on-the-fly, but I'd rather store my .coffee files external to the page.

To try and figure out how to do this, I sent a message to the Scalate Google Group asking Does Scalate allow for referencing (and compiling) CoffeeScript files like the plugin for Play? My email prompted the Scalate Team to do some modifications that seemed to do exactly what I was looking for.

FWIW I've just checked in a couple of coffeescript examples. To run it, grab the code & do a local build...

http://scalate.fusesource.org/source.html
http://scalate.fusesource.org/building.html

then run this...
cd samples/scalate-example 
mvn jetty:run
then open http://localhost:8080/coffee/index

there are 2 sample jade files which use embedded coffee or a separate coffee file (using the .js extension in the <script src attribute>

https://github.com/scalate/scalate/tree/master/samples/scalate-exampl...

e.g. here's a jade file references a separate .js file for a coffee script which gets converted to .js on the server...

https://github.com/scalate/scalate/blob/master/samples/scalate-exampl...

To try out the improved CoffeeScript support, I checked out the source and fumbled with Git branches for a bit before I got latest version of Scalate to build. Unfortunately, it didn't work because Play doesn't know how to process the .js and .css files.

@67o8fflce 
Application.foo.js action not found 
Action not found 
Action Application.foo.js could not be found. Error raised is 
Controller controllers.Application.foo not found 
play.exceptions.ActionNotFoundException: Action Application.foo.js not 
found 
        at play.mvc.ActionInvoker.getActionMethod(ActionInvoker.java: 
588) 
        at play.mvc.ActionInvoker.resolve(ActionInvoker.java:85) 
        at Invocation.HTTP Request(Play!) 
Caused by: java.lang.Exception: Controller controllers.Application.foo 
not found 
        ... 3 more 
08:20:21,133 ERROR ~

Based on this error, I assumed I needed a Controller to do receive the .js and .css requests and compile them accordingly with Scalate. I changed my Jade template to have the following:

script(src="/assets/foo.js" type="text/javascript") 

Then I added a new route to my Play application:

  GET     /                           Application.index
  GET     /assets/{template}          ScalateResource.process

My ScalateResource.scala class is as follows:

package controllers 

import play.mvc._ 

object ScalateResource extends Controller { 

  def process(args: (Symbol, Any)*) = { 
    var template = params.get("template") 
    // replace .js with .coffee 
    template = template.replace(".js", ".coffee") 
    // replace .css with .scss 
    template = template.replace(".css", ".scss") 
    ScalateTemplate(template).render(); 
  } 
} 

Unfortunately, when I tried to access http://localhost:9000/assets/foo.js, I received the following error:

TemplateException occured : Not a template file extension (md | markdown | ssp | scaml | mustache | jade), you requested: coffee

At this point, I still haven't figured out how to solve this. I can only assume that the reason this works in the example application is because it uses a TemplateEngineFilter that's mapped to /*.

As I see it, I have a few choices if I want to continue using CoffeeScript and Scalate in my application:

  1. Revert to an older build of Scalate that uses the in-browser CoffeeScript compiler.
  2. Try to get a new version released that fixes the comment bug and use inline CoffeeScript.
  3. Keep trying to figure out how to get external files compiled by Scalate.

Obviously, I'd like to do #3 the most, but with the lack of responses from the Scalate group, this seems like the most challenging. Since #1 is the easiest (and I can complete without anyone's help), I'll be going that route for now. With any luck, the 2nd and third solutions will surface as options before my talk in November.

Update Oct 4, 2011: I was able to get external CoffeeScript files working! It was rather simple actually. I just tried the Play CoffeeScript module again, using Scalate's {uri("/path")} helper. For example, in a Jade template:

script(type="text/javascript" src={uri("/public/javascripts/script.coffee")})

This compiles the CoffeeScript file on the server and returns JavaScript. Sweet!

Posted in Java at Sep 27 2011, 01:59:18 PM MDT 3 Comments

Integrating Scalate and Jade with Play 1.2.3

At the beginning of this year, I decided I wanted to learn Scala. Since I'm a Web Frameworks Aficionado, I figured the best way to do that would be to learn Lift. I entered these two items on my todo list and let them lie for a couple months. After attending TSSJS 2011 and having a conversation with James Strachan, I added a couple more technologies to my learning list. James had great things to say about both CoffeeScript and Jade and I decided to learn those as well.

In May, Devoxx announced their Call For Papers and I started reminiscing about how awesome last year's trip was. I decided I'd try to get accepted again and started brainstorming about talks I'd like to give. I came up with "Comparing Scala Web Frameworks" and "HTML5 with Play Scala, CoffeeScript and Jade". The reason I chose Play over Lift for the latter talk is because I think it fits a lot more with the MVC mindset I have and the easy-to-learn nature of web frameworks I enjoy using. Both topics sounded very interesting to me, and I figured they'd also inspire me to learn the technologies in a brute-force fashion; where I was under a time constraint and would be embarrassed in front of a large audience if I didn't succeed.

In mid-July, I got an email from Stephan inviting me to speak again at the 10th edition of Devoxx. I smile splashed across my face and I quickly realized I had a lot to learn. Since I was still in vacation mode after summer vacation in Montana, I decided to wait until I returned from Cape Cod to start studying. While on my 2nd summer vacation, I received an email from Devoxx stating that they'd like me present "HTML5 with Play/Scala, CoffeeScript and Jade".

To learn all these technologies, I decided on an In Anger approach - where I would study minimally and learn mostly by doing. I ordered CoffeeScript on August 8th and Programming in Scala, 2nd Edition the following week (August 17th). I started reading both books while traveling the following week (I found CoffeeScript and Scala to be very similar, so I don't know if I'd recommend learning them at the same time). That same week, I started integrating Scalate (Jade) into a new Play Scala application.

Scalate advertises on their homepage that it works with Play via the play-scalate module. They neglect to mention that this module hasn't been updated in over a year or what version of Play it works with. I tried to use the scalate-0.7.2 version and quickly ran into issues. I posted a message to the Scalate Google Group explaining my compilation issues and stacktraces. The response? Crickets.

Next, I tried posting to the Play Google Group and got a much better response. Here's what they said:

Looking at the Scalate module code, I don't think it can work as is with Play Scala 0.9.1. The latest version is more than 1 year old, and we have made a lot of changes in the API.
...
The integration of Scalate is pretty difficult if you plan to get the same kind of experience than the native Play scala template regarding auto-reload and error reports.

You can try to port the module to 0.9.1, basically all it has to do is to provide a plugin that detect changes to scaml file, and recompile them. No special integration with the Play API is needed.

After learning that play-scalate was out-of-date, I contacted the project owner via GitHub and tried to get everything working with Play 1.2.3 and Scalate 1.5.1. I updated the dependencies in the project, fixed compilation issues and tried to build. No dice:

build: 
    [mkdir] Created dir: /Users/mraible/dev/play-scalate/tmp/classes 
   [scalac] Compiling 7 source files to /Users/mraible/dev/play-scalate/tmp/classes 
   [scalac] error: class file needed by Binding is missing. 
   [scalac] reference type Serializable of package scala refers to nonexisting symbol. 
   [scalac] one error found

I posted this error to the Play Group, discovered it was caused by Scalate 1.5.1 requiring Scala 2.9. I downgraded to Scalate 2.4.1 and got another nice cryptic error:

build: 
    [mkdir] Created dir: /Users/mraible/dev/play-scalate/tmp/classes 
   [scalac] Compiling 7 source files to /Users/mraible/dev/play-scalate/tmp/classes 
   [scalac] error: class file needed by ScalaController is missing. 
   [scalac] reference value dispatch of package <root> refers to nonexisting symbol. 
   [scalac] one error found

Apparently, this was caused by another Scala versioning issue and I was offered a much simpler solution for integrating Scalate. Below are the steps I performed to integrate Scalate 1.4.1 with Play 1.2.3.

  1. Updated dependencies.yml to references Scala and Scalate dependencies.
    require:
        - play
        - play -> scala 0.9.1
        - org.fusesource.scalate -> scalate-core 1.4.1:
            transitive: false
        - org.fusesource.scalate -> scalate-util 1.4.1:
            transitive: false
    
  2. Added Scalate configuration elements to application.conf.
    scalate=jade
    jvm.memory=-Xmx256M
    
  3. Created a ScalateTemplate class to contain the Scalate Engine and render the template.
    package controllers
    
    import play.Play
    
    object ScalateTemplate {
    
      import org.fusesource.scalate._
      import org.fusesource.scalate.util._
    
      lazy val scalateEngine = {
        val engine = new TemplateEngine
        engine.resourceLoader = new FileResourceLoader(Some(Play.getFile("/app/views")))
        engine.classpath = Play.getFile("/tmp/classes").getAbsolutePath
        engine.workingDirectory = Play.getFile("tmp")
        engine.combinedClassPath = true
        engine.classLoader = Play.classloader
        engine
      }
    
      case class Template(name: String) {
        val scalateType = "." + Play.configuration.get("scalate");
    
        def render(args: (Symbol, Any)*) = {
          scalateEngine.layout(name + scalateType, args.map {
            case (k, v) => k.name -> v
          } toMap)
        }
      }
    
      def apply(template: String) = Template(template)
    }
    
  4. Created a Scalate trait to override the render() method in Play's Controller class.
    package controllers
    
    import play.mvc.Http
    
    trait Scalate {
    
      def render(args: (Symbol, Any)*) = {
        def defaultTemplate = Http.Request.current().action.replace(".", "/")
        ScalateTemplate(defaultTemplate).render(args: _*);
      }
    }
    
  5. Created an Application.scala controller with a default index method.
    package controllers
    
    import play.mvc._
    import models._
    
    object Application extends Controller with Scalate {
    
      def index = {
        render('user -> User("Raible"))
      }
    }
    
    The models/User.scala class is very simple:
    package models
    
    case class User(name:String)
    
  6. Lastly, I created an index.jade file in views/Application.
    -@ var user: models.User
    p Hi #{user.name},
    - for(i <- 1 to 3)
      p= i
    p See, I can count!
    

After getting all this working, I decided it was time to get it into production. As luck would have it, Heroku had just announced Play support a few days earlier. I heard through the grapevine that Play Scala would work, so I gave it a try. It was amazingly easy. All I had to do was create an account, create a "Procfile" in my application's root directory and run a heroku command followed by a git push. It all looked great until Play tried to compile my Jade templates as Groovy templates:

Cannot start in PROD mode with errors 
Template compilation error (In /app/views/Application/index.jade around line 2) 
The template /app/views/Application/index.jade does not compile : #{user.name} is not closed. 
play.exceptions.TemplateCompilationException: #{user.name} is not closed. 
       at play.templates.TemplateCompiler.generate(TemplateCompiler.java:102) 
       at play.templates.TemplateCompiler.compile(TemplateCompiler.java:15) 
       at play.templates.GroovyTemplateCompiler.compile(GroovyTemplateCompiler.java:4 1)

The solution from Guillaume was simple enough and I renamed my "views" directory to "templates" and updated ScalateTemplate.scala accordingly. You can see the deployed application at http://play-more.herokuapp.com.

The next steps in my Play Scala adventure will be trying to get the CoffeeScript module to work. I also hope to integrate HTML5 Boilerplate with Jade and Scalate Layouts. I'll be doing this with the mindset that HTML and JavaScript aren't that bad. I expect a lot from CoffeeScript and Jade and hope I enjoy them as much as Strachan. ;-)

In the meantime, here's some interesting links I've seen recently encountered that discuss Scala and/or Play. I dig the passion and activity that exists in these communities.

Posted in Java at Sep 07 2011, 01:21:41 PM MDT 10 Comments