TemplateModel _getAsTemplateModel(Environment env) throws TemplateException 
{
        TemplateModel model = target.getAsTemplateModel(env);
        Expression sourceExpr = null;
        String id = "anonymous_interpreted";
        if(model instanceof TemplateSequenceModel)
        {
            sourceExpr = ((Expression)new DynamicKeyName(target, new NumberLiteral(new Integer(0))).copyLocationFrom(target));
            if(((TemplateSequenceModel)model).size()  > 1)
            {
                id = ((Expression)new DynamicKeyName(target, new NumberLiteral(new Integer(1))).copyLocationFrom(target)).getStringValue(env);
            }
        }
        else if (model instanceof TemplateScalarModel)
        {
            sourceExpr = target;
        }
        else
        {
            throw invalidTypeException(model, target, env, "sequence or string");
        }
        String templateSource = sourceExpr.getStringValue(env);
        Template parentTemplate = env.getTemplate();
        try
        {
            Template template = new Template(parentTemplate.getName() + "$" + id, new StringReader(templateSource), parentTemplate.getConfiguration());
            template.setLocale(env.getLocale());
            return new TemplateProcessorModel(template);
        }
        catch(IOException e)
        {
            throw new TemplateException("", e, env);
        }
}

Constructs a template on-the-fly and returns it embedded in a TemplateTransformModel .

The built-in has two arguments: the arguments passed to the method. It can receive at least one and at most two arguments, both must evaluate to a scalar. The first scalar is interpreted as a template source code and a template is built from it. The second (optional) is used to give the generated template a name.