Google's HTML (and XML) Compressor for Play Framework 2


Installation

In your project/Build.scala:

libraryDependencies ++= Seq(
  "com.mohiva" %% "play-html-compressor" % "0.6.0"
)

History

• For Play Framework 2.5 use version 0.6.0
• For Play Framework 2.4 use version 0.5.0
• For Play Framework 2.3 use version 0.3.1
• For Play Framework 2.2 use version 0.2.1
• For Play Framework 2.1 use version 0.1-SNAPSHOT

How to use

The filter comes with built-in HtmlCompressor and XmlCompressor configurations, but it can also be used with user-defined configurations. The following two examples shows how to define the filters with the default and the user-defined configurations.

To provide the filters for your application you must define it as described in the Play Documentation (Scala, Java).

Provide filters

For Scala users

import javax.inject.Inject

import com.mohiva.play.htmlcompressor.HTMLCompressorFilter
import com.mohiva.play.xmlcompressor.XMLCompressorFilter
import play.api.http.HttpFilters
import play.api.mvc.EssentialFilter

class Filters @Inject() (
  htmlCompressorFilter: HTMLCompressorFilter, 
  xmlCompressorFilter: XMLCompressorFilter) 
  extends HttpFilters {
  
  override def filters: Seq[EssentialFilter] = Seq(
    htmlCompressorFilter, 
    xmlCompressorFilter
  )
}

For Java users

import com.mohiva.play.htmlcompressor.HTMLCompressorFilter;
import com.mohiva.play.xmlcompressor.XMLCompressorFilter;
import play.api.mvc.EssentialFilter;
import play.http.HttpFilters;

import javax.inject.Inject;

public class DefaultFilter implements HttpFilters {

    private HTMLCompressorFilter htmlCompressorFilter;
    private XMLCompressorFilter xmlCompressorFilter;

    @Inject
    public DefaultFilter(
        HTMLCompressorFilter htmlCompressorFilter, 
        XMLCompressorFilter xmlCompressorFilter) {
        
        this.htmlCompressorFilter = htmlCompressorFilter;
        this.xmlCompressorFilter = xmlCompressorFilter;
    }

    @Override
    public EssentialFilter[] filters() {
        return new EssentialFilter[] {
            htmlCompressorFilter, 
            xmlCompressorFilter
        };
    }
}

Default filter

For the default filters we provide DI modules which will be automatically enabled if you pull in the dependency. You must only provide your instance of HttpFilters as described above.

User-defined filter

For user defined filters there is a little bit mor to do. First you must create your instances of the filter. As next you must provide your instance of HttpFilters as described above. At last you must provide the bindings for you created filter and disable the default DI modules.

Implement filters

For Scala users

import javax.inject.Inject

import akka.stream.Materializer
import com.googlecode.htmlcompressor.compressor.HtmlCompressor
import com.mohiva.play.htmlcompressor.HTMLCompressorFilter
import play.api.{Configuration, Environment, Mode}

class CustomHTMLCompressorFilter @Inject() (
  val configuration: Configuration, environment: Environment, val mat: Materializer)
  extends HTMLCompressorFilter {

  override val compressor: HtmlCompressor = {
    val c = new HtmlCompressor()
    if (environment.mode == Mode.Dev) {
      c.setPreserveLineBreaks(true)
    }

    c.setRemoveComments(true)
    c.setRemoveIntertagSpaces(false)
    c.setRemoveHttpProtocol(true)
    c.setRemoveHttpsProtocol(true)
    c
  }
}

For Java users

import akka.stream.Materializer;
import com.googlecode.htmlcompressor.compressor.HtmlCompressor;
import com.mohiva.play.htmlcompressor.HTMLCompressorFilter;
import play.Environment;
import play.Mode;
import play.api.Configuration;

import javax.inject.Inject;

public class CustomHTMLCompressorFilter extends HTMLCompressorFilter {

    private Configuration configuration;
    private Environment environment;
    private Materializer mat;

    @Inject
    public CustomHTMLCompressorFilter(
        Configuration configuration, Environment environment, Materializer mat) {
        
        this.configuration = configuration;
        this.environment = environment;
        this.mat = mat;
    }

    @Override
    public Configuration configuration() {
        return configuration;
    }

    @Override
    public HtmlCompressor compressor() {
        HtmlCompressor compressor = new HtmlCompressor();
        if (environment.mode() == Mode.DEV) {
            compressor.setPreserveLineBreaks(true);
        }

        compressor.setRemoveComments(true);
        compressor.setRemoveIntertagSpaces(true);
        compressor.setRemoveHttpProtocol(true);
        compressor.setRemoveHttpsProtocol(true);

        return compressor;
    }
    
    @Override
    public Materializer mat() {
        return mat;
    }
        
}

Provide bindings

To provide your bindings for your user defined filter you must either create a new module or you can add the binding to your default DI module. This process is detailed documented for Scala and Java users. So please refer to this documentation.

Disable default modules

To disable the default modules you must append the modules to the play.modules.disabled property in application.conf:

play.modules.disabled += "com.mohiva.play.htmlcompressor.HTMLCompressorFilterModule"
play.modules.disabled += "com.mohiva.play.xmlcompressor.XMLCompressorFilterModule"