Script helper

It is possible to use a script helper in scripts. A script helper allows to define helper methods associated with your application. Note that these methods can also be defined in the script context, but it is clearer to define a specific class for them.

It there is a script helper, it is available through the helper field in your script. For example:

   public void apply() {
      helper.doSomeComputation();
   }

Adding a script Helper

If you want to have a script helper, you must use a custom script context and implement the ScriptContext.getHelper() method.

For example for the CustomContext class:

   public class CustomContext extends DefaultScriptContext {
     private final CustomHelper helper;

     public CustomContext() {
       helper = new CustomHelper(this);
     }

     public ScriptHelper getHelper() {
       return helper;
     }
   }

And for the CustomHelper class:

   public class CustomHelper implements ScriptHelper {
     private final ScriptContext context;

     public CustomHelper(ScriptContext context) {
       this.context = context;
     }

     public double doSomeComputation(double angle) {
       return Math.sin(angle);
     }

We can perform in a Script:

   public void apply() {
     double result = helper.doSomeComputation(1.2d);
     context.echo(result);
   }

Default script Helper

The DefaultScriptHelper class is a basic default script helper which implements the ScriptContext.getHelper() method.



For example for the previous example:

   public class CustomHelper extends DefaultScriptHelper {
     public double doSomeComputation(double angle) {
       return Math.sin(angle);
     }
   }

Helper API

By default the helper has only one method:

• ScriptHelper.getContext(): Return the script context