Hi Keith,
I'm "resurrecting" this old thread in an attept to see if we can use Groovy as
the next scritpting language in jAlbum. What I'd really want to achive is to
supply a number of default star imports. This is expecially important as Groovy
sadly doesn't remember imports between script invocations.
I looked at your code suggetion below and tried to fit it to JSR-223
(javax.script API) but it fails as the GroovyScriptEngineImpl class I get from
that API doesn't extend the GroovyScriptEngine class. It's only the
GroovyScriptEngine class that supplies the important setConfig method.
Could you revise the JSR-223 implementation so it isn't unnecessary crippled
compared to the GroovyShell API, at very least add the setConfig method to the
GroovyScriptEngineImpl class? If we're to use the GroovyShell API, then we need
to introduce our own abstraction layer in order to continue supporting multiple
scripting languages in jAlbum.
Regards
/David, jAlbum founder
> On 10 Feb 2018, at 21:25, Keith Suderman <suder...@anc.org> wrote:
>
> Import statements are really just shortcuts to tell the compiler how to
> resolve class names so there is nothing to "remember" between invocations,
> that is, nothing gets added to the Binding.
>
> I am not familiar with the javax.script API, but I suspect that you will have
> to provide your own ScriptEngine implementation as you will need to modify
> the CompilerConfiguration object the GroovyShell is using to compile the
> Groovy code. For example:
>
> CompilerConfiguration configuration = new CompilerConfiguration()
> GroovyShell compiler = new GroovyShell(configuration)
> println compiler.evaluate('json=\'{"foo":"bar"}\'')
> println compiler.evaluate("groovy.json.JsonOutput.prettyPrint(json)")
>
> /* Fails: MissingPropertyException */
> /* println compiler.evaluate("JsonOutput.prettyPrint(json)") */
>
> ImportCustomizer imports = new ImportCustomizer()
> imports.addStarImports("groovy.json")
> configuration.addCompilationCustomizers(imports)
> // Works, the compiler can now resolve groovy.json.JsonOutput
> println compiler.evaluate("JsonOutput.prettyPrint(json)")
>
> The difficult part will be "hooking" into the compiler to know when an import
> statement is used so you can update your CompilerConfiguration object. I am
> sure the really clever programmers here could come up with some sort of AST
> transform that would do this. However, depending on what you are allowed to
> do one option would be to tell your users that you have a "Groovy DSL" and
> then implement an "include" method that users would use to "import" Java
> packages.
>
> println eval('json=\'{"foo":"bar"}\'')
> println eval('include "groovy.json"')
> println eval('JsonOutput.prettyPrint(json)')
>
> Object eval(String code) {
> Script script = compiler.parse(code)
> ExpandoMetaClass metaClass = new ExpandoMetaClass(script.class, false)
> metaClass.include = { String name ->
> ImportCustomizer includes = new ImportCustomizer()
> includes.addStarImports(name)
> configuration.addCompilationCustomizers(includes)
> "Imported $name"
> }
> metaClass.initialize()
> script.metaClass = metaClass
> script.run()
> }
>
> Hopefully that gives you some ideas.
>
> Cheers,
> Keith
>
>> On Feb 8, 2018, at 3:47 PM, David Ekholm <da...@jalbum.net
>> <mailto:da...@jalbum.net>> wrote:
>>
>> How do I do that via the javax.script API?
>>
>> Even if this is possible via the javax.script API, chances are that a user
>> wishes to ad-hoc add another import, but as they are forgotten between
>> script invocations, it makes it hard to use Groovy to interactively create,
>> say a Swing or JavaFX UI one line at a time. With BeanShell, the user can
>> add the needed imports, execute that "script" and then continue to refer to
>> the imported classes in the following script invocations. Making Groovy
>> remember imports would make it behave in as nice fashion as the new JShell
>> tool in Java 9. JShell unfortunately cannot run embedded via the
>> javax.script API :-(
>>
>> Regards
>> /David
>>
>>> On 8 Feb 2018, at 21:34, eric.mil...@thomsonreuters.com
>>> <mailto:eric.mil...@thomsonreuters.com> wrote:
>>>
>>> You can add all the imports you want to your compiler configuration and
>>> they will be consistently available for all scripts.
>>>
>>> From: David Ekholm [mailto:da...@jalbum.net <mailto:da...@jalbum.net>]
>>> Sent: Thursday, February 08, 2018 2:12 PM
>>> To: dev@groovy.apache.org <mailto:dev@groovy.apache.org>
>>> Subject: Remembering imports between script invocations
>>>
>>> We're considering supporting Groovy as an additional scripting language to
>>> our web gallery software jAlbum (http://jalbum.net
>>> <https://urldefense.proofpoint.com/v2/url?u=http-3A__jalbum.net&d=DwMFAg&c=4ZIZThykDLcoWk-GVjSLmy8-1Cr1I4FWIvbLFebwKgY&r=tPJuIuL_GkTEazjQW7vvl7mNWVGXn3yJD5LGBHYYHww&m=39n_uU4e7-n_s_WwrNC_8tQYLfhWKgmT_dDWwJw8ctA&s=jGwsu2zf5Pm3kG3GKLFFxalyi30aoXq_-izsMrEy_iQ&e=>),
>>> but one aspect bugs me: It doesn't seem like import statements are
>>> remembered between script invocations. This makes it far harder to use
>>> Groovy to prototype UIs within jAlbum's scripting console than for instance
>>> BeanShell (using the javax.script API). We currently support the slow
>>> BeanShell scripting language and JavaScript. BeanShell behaves well in this
>>> regard, remembering earlier imported packages between script invocations.
>>> Can this be added to Groovy or is there some API flag we can set?
>>>
>>> Regards
>>> /David, jAlbum founder and client lead developer.
>>
>
> ----------------------
> Keith Suderman
> Research Associate
> Department of Computer Science
> Vassar College, Poughkeepsie NY
> suder...@cs.vassar.edu <mailto:suder...@cs.vassar.edu>
>
>
>
>
