Templates in maps loaded via STGroupFile do not use registered ObjectModelAdaptors

Given ST4 4.1 on the JVM and the following code, I would expect that the View would be dumped out identically both times. However, the following is produced:

before template = View(regularName=HIP! HIP!,special_name=HUZZAH!) and after map template = View(regularName=HIP! HIP!,special_name=)

It seems that the templates in the map create a new group based on the file they appear in but this new group does not inherit the model adaptor registrations from the original group. Much confusion ensues.

import org.stringtemplate.v4.*
import org.stringtemplate.v4.misc.*
import java.nio.charset.StandardCharsets

class Adaptor : ObjectModelAdaptor() {
    override fun getProperty(interp: Interpreter, self: ST, o: Any, property: Any?, propertyName: String): Any? =
        if (propertyName == "special_name")
            "HUZZAH!"
        else
            super.getProperty(interp, self, o, property, propertyName)
}

class View(val regularName: String)

fun main(args: Array<String>) {
    val group = STGroupFile(View::class.java.getResource("/strepl/main.stg"), StandardCharsets.UTF_8.name(), '$', '$')
    group.registerModelAdaptor(Object::class.java, Adaptor())
    val st = group.getInstanceOf("main")
    st.add("view", View("HIP! HIP!"))
    println(st.render())
}

/strepl/main:

import "other.stg"

main(view) ::= "$other_main(view)$"

/strepl/other:

delimiters "$", "$"

other_main(view) ::= "before template = $dump(view)$ and after $map.(\"simple\")$"
map ::= [
    "simple": <%map template = $dump(view)$%>
]
dump(view) ::= "View(regularName=$view.regularName$,special_name=$view.special_name$)"

For anyone that finds this, the workaround I am using is to just store template names in the map and use double indirection to invoke them:

... $(map.(\"simple\"))()$ ...

and

map ::= [
    "simple": "simple_template"
]

simple_template() ::= "map template = $dump(view)$"

It is slightly more verbose, but not so terrible as workarounds go :)

hi. is this Kotlin? Might matter. E.g., what if an object gets wrapped and no longer a java object? Maybe the registration no longer works?

It is Kotlin. The registrations work, just not after "passing through" a mapped template in a loaded group file.

I will provide a Java repro after the weekend.

Thanks.

ok, yeah, Maybe there's something about parameter handoff or dynamic scoping that is screwing something up here.

Here is the Java 11 repro (using the same template files above):

package test;

import org.stringtemplate.v4.Interpreter;
import org.stringtemplate.v4.ST;
import org.stringtemplate.v4.STGroupFile;
import org.stringtemplate.v4.misc.ObjectModelAdaptor;

import java.nio.charset.StandardCharsets;

public class ST4BugReplJava {
    static class Adaptor extends ObjectModelAdaptor {
        @Override
        public Object getProperty(Interpreter interp, ST self, Object o, Object property, String propertyName) {
            if (propertyName.equals("special_name"))
                return "HUZZAH!";
            return super.getProperty(interp, self, o, property, propertyName);
        }
    }

    static class View {
        public String regularName;

        public View(String regularName) {
            this.regularName = regularName;
        }
    }

    static public void main(String[] args) {
        var group = new STGroupFile(View.class.getResource("/strepl/main.stg"), StandardCharsets.UTF_8.name(), '$', '$');
        group.registerModelAdaptor(Object.class, new Adaptor());
        var st = group.getInstanceOf("main");
        st.add("view", new View("HIP! HIP!"));
        System.out.println(st.render());
    }
}

Navigation Menu

Repository navigation

Templates in maps loaded via STGroupFile do not use registered ObjectModelAdaptors #223

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Templates in maps loaded via STGroupFile do not use registered ObjectModelAdaptors #223

Description

Activity

Aethon commented on Oct 2, 2019

parrt commented on Oct 5, 2019

Aethon commented on Oct 5, 2019

parrt commented on Oct 5, 2019

Aethon commented on Oct 6, 2019

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions