OK, I use now your proposal.

But I have another problem, with code you proposed I think:

I have in index.htt at line number 359 this code:

<ja:if test="<%= jAlbumVersion > 23 %>">
<%
usingFallback()  {
  import net.jalbum.*;
  ImageRenderer renderer = currentObject.getRenderer();
  if (ImageRenderer.getTypical(renderer.getCloseupRenditions()).getFormat() == OutputFormat.WEBP) {
    return false;
  }
  for (Rendition r :  renderer.getCloseupRenditions()) {
    if (r.getFormat() == OutputFormat.WEBP) {
      return true;
    }
  }
  return false;
}
 useFallback = usingFallback() ; %>
</ja:if>

In Groovy I get this:

Making "FB_JustifiedGallery_Simple_groovy" (Changes)
se.datadosen.util.ScriptException: org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Script715.groovy: 3: Unexpected input: 'usingFallback()  {\r\n  import' in index.htt at line number 359 at column number 3
	at se.datadosen.util.ScriptException.of(ScriptException.java:59)
	at se.datadosen.jalbum.ast.ScriptletNode.doEval(ScriptletNode.java:99

How should I solve this?

Edit:

I moved

import net.jalbum.*;

to init.Groovy, but then I get this error:

 se.datadosen.util.ScriptException: groovy.lang.MissingMethodException: No signature of method: net.jalbum.script.GroovierScriptEngine.usingFallback() is applicable for argument types: (Script1009$_run_closure1) values: [Script1009$_run_closure1@767eb245] in index.htt at line number 359
	at se.datadosen.util.ScriptException.of(ScriptException.java:59)

Edited by: AndreWolff on 3 Nov 2022, 10:53

This is the solution:

<ja:if test="<%= jAlbumVersion > 23 %>">
<%
private usingFallback()  {

Edited by: AndreWolff on 3 Nov 2022, 11:14

Well both private and boolean are accepted in Groovy.

BeanShell:

String newString = originalString.substring(0, index + 1) 
                           + stringToBeInserted 
                           + originalString.substring(index + 1); 

Groovy:

String newString = originalString.substring(0, index + 1)  + stringToBeInserted   + originalString.substring(index + 1); 

No, if you Google this problem, you will see dat a + sign in front of a string on a new line is not accepted in Groovy, the + sign is only accepted after a string.

This is also accepted:

 String newString = originalString.substring(0, index + 1)  +
                            stringToBeInserted  +
                            originalString.substring(index + 1);