# IndexException whenever using PyArgParser

**URL:** <https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692>\
**Category:** Module Development\
**Created:** [August 4, 2022, 6:05pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692 "2022-08-04T18:05:10Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![kgamble](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kgamble/32/8019_2.png) [@kgamble](https://forum.inductiveautomation.com/u/kgamble)\
**Post date:** [August 4, 2022, 6:05pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/1 "2022-08-04T18:05:10Z")

</div>

I am trying to create a scripting function using `PyArgParser.getParser` and following a few other postings with it, however no matter what I do I keep running into the same exception whenever I pass any args or kwargs into the function.

### My Implementation

```python
@Override
@ScriptFunction(docBundlePrefix = "ConfigScripts")
@KeywordArgs(names={"configPath"}, types={String.class})
public PyObject getConfig(PyObject[] pyArgs, String[] keywords) throws ProjectInvalidException, JSONException {
    PyArgParser args = PyArgParser.parseArgs(pyArgs, keywords, new String[] {"configPath"}, new Class[] {String.class}, "getConfig");

    String configPath = args.getString("configPath").orElse(null);

    if (configPath == null) {
        throw new IllegalArgumentException("configPath is a required keyword or positional argument");
    }

    return getConfigImpl(configPath);
}

```

I have also tried using the `PyArgParser.parseArgs(pyArgs, keywords, ConfigScriptModule.class, "getConfig")` variant to get the parser, and no matter what I do I run into the same `ArrayIndexOutOfBoundsException`. Note, line 42 is the line with the `PyArgParser.parseArgs` call.

```python
Caused by: java.lang.ArrayIndexOutOfBoundsException: Index -2 out of bounds for length 0
	at com.inductiveautomation.ignition.common.script.PyArgParser.<init>(PyArgParser.java:153)
	at com.inductiveautomation.ignition.common.script.PyArgParser.parseArgs(PyArgParser.java:55)
	at com.bwdesigngroup.ignition.configmanager.common.scripting.ConfigScriptModule.getConfig(ConfigScriptModule.java:42)

```

> **Full Traceback**
>
> ```python
> Jython 2.7.2 (uncontrolled:000000000000, Jan 25 2022, 14:39:15)
> [OpenJDK 64-Bit Server VM (Azul Systems, Inc.)] on java11.0.15
> 
> >>> 
> Java Traceback:
> Traceback (most recent call last):
> File "<input>", line 1, in <module>
> at com.sun.proxy.$Proxy57.getConfig(Unknown Source)
> at com.bwdesigngroup.ignition.configmanager.client.scripting.ClientScriptModule.getConfigImpl(ClientScriptModule.java:37)
> at com.bwdesigngroup.ignition.configmanager.common.scripting.ConfigScriptModule.getConfig(ConfigScriptModule.java:50)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
> at java.base/java.lang.reflect.Method.invoke(Unknown Source)
> java.lang.reflect.UndeclaredThrowableException: java.lang.reflect.UndeclaredThrowableException
> 
> at org.python.core.Py.JavaError(Py.java:547)
> at org.python.core.Py.JavaError(Py.java:538)
> at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:192)
> at com.inductiveautomation.ignition.common.script.ScriptManager$ReflectedInstanceFunction. __call__ (ScriptManager.java:549)
> at org.python.core.PyObject. __call__ (PyObject.java:400)
> at org.python.pycode._pyx11.f$0(<input>:1)
> at org.python.pycode._pyx11.call_function(<input>)
> at org.python.core.PyTableCode.call(PyTableCode.java:173)
> at org.python.core.PyCode.call(PyCode.java:18)
> at org.python.core.Py.runCode(Py.java:1687)
> at org.python.core.Py.exec(Py.java:1731)
> at org.python.util.PythonInterpreter.exec(PythonInterpreter.java:277)
> at org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter.java:130)
> at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:611)
> at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:599)
> at java.desktop/javax.swing.SwingWorker$1.call(Unknown Source)
> at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
> at java.desktop/javax.swing.SwingWorker.run(Unknown Source)
> at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
> at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
> at java.base/java.lang.Thread.run(Unknown Source)
> Caused by: java.lang.reflect.UndeclaredThrowableException
> at com.sun.proxy.$Proxy57.getConfig(Unknown Source)
> at com.bwdesigngroup.ignition.configmanager.client.scripting.ClientScriptModule.getConfigImpl(ClientScriptModule.java:37)
> at com.bwdesigngroup.ignition.configmanager.common.scripting.ConfigScriptModule.getConfig(ConfigScriptModule.java:50)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
> at java.base/java.lang.reflect.Method.invoke(Unknown Source)
> at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:190)
> ... 18 more
> Caused by: com.inductiveautomation.ignition.client.gateway_interface.GatewayException: Index -2 out of bounds for length 0
> at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.newGatewayException(GatewayInterface.java:351)
> at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.sendMessage(GatewayInterface.java:325)
> at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.sendMessage(GatewayInterface.java:278)
> at com.inductiveautomation.ignition.client.gateway_interface.GatewayInterface.moduleInvokeSafe(GatewayInterface.java:917)
> at com.inductiveautomation.ignition.client.gateway_interface.ModuleRPCFactory$DynamicRPCHandler.invoke(ModuleRPCFactory.java:53)
> ... 26 more
> Caused by: java.lang.ArrayIndexOutOfBoundsException: Index -2 out of bounds for length 0
> at com.inductiveautomation.ignition.common.script.PyArgParser.<init>(PyArgParser.java:153)
> at com.inductiveautomation.ignition.common.script.PyArgParser.parseArgs(PyArgParser.java:55)
> at com.bwdesigngroup.ignition.configmanager.common.scripting.ConfigScriptModule.getConfig(ConfigScriptModule.java:42)
> at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(null)
> at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(null)
> at java.lang.reflect.Method.invoke(null)
> at com.inductiveautomation.ignition.gateway.servlets.gateway.functions.ModuleInvoke.invoke(ModuleInvoke.java:167)
> at com.inductiveautomation.ignition.gateway.servlets.Gateway.doPost(Gateway.java:431)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
> at com.inductiveautomation.ignition.gateway.bootstrap.MapServlet.service(MapServlet.java:86)
> at org.eclipse.jetty.servlet.ServletHolder$NotAsync.service(ServletHolder.java:1450)
> at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
> at org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1631)
> at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:548)
> at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
> at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:600)
> at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
> at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
> at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
> at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
> at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440)
> at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
> at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:501)
> at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
> at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
> at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355)
> at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
> at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
> at com.inductiveautomation.catapult.handlers.RemoteHostNameLookupHandler.handle(RemoteHostNameLookupHandler.java:121)
> at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
> at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:322)
> at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:59)
> at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:146)
> at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
> at org.eclipse.jetty.server.Server.handle(Server.java:516)
> at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487)
> at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732)
> at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479)
> at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
> at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
> at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
> at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
> at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
> at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
> at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
> at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131)
> at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409)
> at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
> at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
> at java.lang.Thread.run(null)
> Traceback (most recent call last):
> File "<input>", line 1, in <module>
> at com.sun.proxy.$Proxy57.getConfig(Unknown Source)
> at com.bwdesigngroup.ignition.configmanager.client.scripting.ClientScriptModule.getConfigImpl(ClientScriptModule.java:37)
> at com.bwdesigngroup.ignition.configmanager.common.scripting.ConfigScriptModule.getConfig(ConfigScriptModule.java:50)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
> at java.base/java.lang.reflect.Method.invoke(Unknown Source)
> java.lang.reflect.UndeclaredThrowableException: java.lang.reflect.UndeclaredThrowableException
> >>> 
> 
> ```

I appreciate any ideas, I really am just aiming for this to be a one positional arg (or keyword arg) function.

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [August 4, 2022, 8:05pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/2 "2022-08-04T20:05:57Z")

</div>

I think things are getting confused over the RPC bridge. Are you sure your signatures line up throughout? Are you trying to directly call a method that accepts `PyObject[]/String[]` from Java code?

As an aside, you can simplify your first snippet by using `orElseThrow()` on the `Optional<String>`:  
`String configPath = args.getString("configPath").orElseThrow(new IllegalArgumentException("configPath is a required keyword or positional argument"));`

---

<div class="post-metadata">

**Author:** ![bmusson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmusson/32/87530_2.png) [@bmusson](https://forum.inductiveautomation.com/u/bmusson)\
**Post date:** [August 4, 2022, 8:12pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/3 "2022-08-04T20:12:02Z")

</div>

Ever simpler:

```auto
String configPath = args.requireString("configPath")

```

---

<div class="post-metadata">

**Author:** ![kgamble](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kgamble/32/8019_2.png) [@kgamble](https://forum.inductiveautomation.com/u/kgamble)\
**Post date:** [August 4, 2022, 8:16pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/4 "2022-08-04T20:16:47Z")

</div>

> [@paul-griffith](#):
>
> I think things are getting confused over the RPC bridge. Are you sure your signatures line up throughout? Are you trying to directly call a method that accepts `PyObject[]/String[]` from Java code?

I stepped through all of them to make sure I had the right types, I only take the `PyObject[]/String[]` from the script interface and the abstract script module.

My actual implemented function takes the `String configPath` parameter that comes out of the python params, so my client side implementation also only takes that, then when I make the RPC I am creating new objects. Maybe there is something wrong here?

```auto
@Override
    protected PyObject getConfigImpl(String configPath) throws ProjectInvalidException, JSONException {
        return rpc.getConfig(new PyObject[]{}, new String[]{"configPath", configPath});
        // return rpc.getConfig(configPath);
    }

```

> [@paul-griffith](#):
>
> As an aside, you can simplify your first snippet by using `orElseThrow()` on the `Optional<String>`:  
> `String configPath = args.getString("configPath").orElseThrow(new IllegalArgumentException("configPath is a required keyword or positional argument"));`

This looks much cleaner, however I am getting an issue with the parameter for `orElseThrow()`, do I need to be casting that argument?

```auto
The method orElseThrow(Supplier<? extends X>) in the type Optional<String> is not applicable for the arguments (IllegalArgumentException)Java(67108979)

```

EDIT: I like the `requireString()` even better, unless that doesn't work when the value gets passed as a positional, will have to try that out when I get the `PyArgParser` working...

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [August 4, 2022, 8:21pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/5 "2022-08-04T20:21:08Z")

</div>

> [@kgamble](#):
>
> My actual implemented function takes the `String configPath` parameter that comes out of the python params, so my client side implementation also only takes that, then when I make the RPC I am creating new objects. Maybe there is something wrong here?

I don't think you want to be passing `PyObject[]` or `String[]`s over RPC. Your RPC methods should just take the (direct) Java arguments they need, so in this case I would expect just a plain String parameter. You may want to use a more specific return type than PyObject for your return value, as well, depending on what it's supposed to act as.

> [@kgamble](#):
>
> This looks much cleaner, however I am getting an issue with the parameter for `orElseThrow()`, do I need to be casting that argument?

Oh, right. `orElseThrow()` takes a supplier (a functional interface), so you would construct a lambda:  
`String configPath = args.getString("configPath").orElseThrow(() -> new IllegalArgumentException("configPath is a required keyword or positional argument"));`

But Ben is correct that `requireX` is cleaner; it will throw a Jython TypeError instead of an IAE, making catching from Jython code a little more idiomatic.

---

<div class="post-metadata">

**Author:** ![kgamble](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kgamble/32/8019_2.png) [@kgamble](https://forum.inductiveautomation.com/u/kgamble)\
**Post date:** [August 4, 2022, 8:47pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/6 "2022-08-04T20:47:22Z")

</div>

> [@paul-griffith](#):
>
> You may want to use a more specific return type than PyObject for your return value, as well, depending on what it’s supposed to act as.

Essentially this method is calling `SystemUtilities.jsonDecode` on a Json string and returning that to the client, is there a more clear PyObject type to use in that case?

> [@paul-griffith](#):
>
> I don’t think you want to be passing `PyObject[]` or `String[]`s over RPC. Your RPC methods should just take the (direct) Java arguments they need, so in this case I would expect just a plain String parameter. You may want to use a more specific return type than PyObject for your return value, as well, depending on what it’s supposed to act as.

I think I understood this correctly, I got it working anyways. So to clarify:

### My Client Implementation calls a new method that takes java types

```python
@Override
protected PyObject getConfigImpl(String configPath) throws ProjectInvalidException, JSONException {
    return rpc.getConfigOverRPC(configPath);
}

```

### In my script module I added an @NoHint method that is accessed directly over RPC, that calls the same function as the hinted one, but without ever using python types

```python
@NoHint
public PyObject getConfigOverRPC(String configPath) throws ProjectInvalidException, JSONException {
    return getConfigImpl(configPath);
}

```

### My hinted function remains, and doesn't ever get called in the client scope, it just looks like it does visually to the user

```python
@Override
@ScriptFunction(docBundlePrefix = "ConfigScripts")
@KeywordArgs(names={"configPath"}, types={String.class})
public PyObject getConfig(PyObject[] pyArgs, String[] keywords) throws ProjectInvalidException, JSONException {
    PyArgParser args = PyArgParser.parseArgs(pyArgs, keywords, new String[] {"configPath"}, new Class[] {String.class}, "getConfig");

    String configPath = args.requireString("configPath");

    return getConfigImpl(configPath);
}

```

Did I get this correct? Or overcomplicate it somewhere?

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [August 4, 2022, 8:56pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/7 "2022-08-04T20:56:21Z")

</div>

> [@kgamble](#):
>
> Essentially this method is calling `SystemUtilities.jsonDecode` on a Json string and returning that to the client, is there a more clear PyObject type to use in that case?

If you know it's going to be a JsonObject, you could return a PyDictionary or PyStringMap. Or return the JSON string over RPC, and then deserialize it into Python object(s) on the client side.

> [@kgamble](#):
>
> Did I get this correct? Or overcomplicate it somewhere?

I think this approach is fine. Are you planning to make this script callable from gateway scope, as well? If so, you may want to (for simplicity) have something like this:

```auto
// common

abstract class ScriptModule {
	public PyObject getConfig(PyObject[], String[]) {
		// do arg handling
		String jsonBody = getConfigImpl(arg);
		return jsonDecode(jsonBody);
	}

	abstract String getConfigImpl(String arg) {}
}

// gateway

class GatewayScriptModule {
	GatewayScriptModule(RPC) {
		this.rpc = RPC;
	}

	String getConfigImpl(String arg) {
		return rpc.getConfigImpl(arg);
	}
}

// client

class ClientScriptModule {
	ClientScriptModule() {
		this.rpc = //obtain RPC reference
	}

	String getConfigImpl(String arg) {
		return rpc.getConfigImpl(arg);
	}
}

```

The idea being that you minimize how often things have to be defined. Your argument parsing can live in one place (in common); your RPC code can live in one place (in gateway), and thus you have to do the minimum amount of work to extend things down the road.

But if you've got it working, I definitely wouldn't sweat it too much.

---

<div class="post-metadata">

**Author:** ![bmusson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmusson/32/87530_2.png) [@bmusson](https://forum.inductiveautomation.com/u/bmusson)\
**Post date:** [August 4, 2022, 9:24pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/8 "2022-08-04T21:24:14Z")

</div>

I’d flip this so that the RPC method delegates to the `GatewayScriptModule`, instead of the other way around.

```auto
class ClientScriptModule {
	ClientScriptModule() {
		this.rpc = //obtain RPC reference
	}

	String getConfigImpl(String arg) {
		return rpc.getConfigImpl(arg);
	}
}

class GatewayScriptModule {
	String getConfigImpl(String arg) {
        String value = // Gateway stuff
		return value
	}
}

class ModuleRPC {

    ModuleRPC () {
        this.gatewayScriptModule = new GatewayScriptModule()
    }

    String getConfigImpl(String arg) {
        return this.gatewayScriptModule.getConfigImpl(arg)
    }
}

```

If you were in Kotlin-land, you could get fancy with Kotlin delegates and do:

```auto
class ClientScriptModule : ScriptModule by ModuleRPCFactory.create(MODULE_ID, ModuleRPC ::class.java) 

class ModuleRPC : ScriptModule by GatewayScriptModule(context)

```

---

<div class="post-metadata">

**Author:** ![kgamble](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kgamble/32/8019_2.png) [@kgamble](https://forum.inductiveautomation.com/u/kgamble)\
**Post date:** [August 4, 2022, 9:38pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/9 "2022-08-04T21:38:45Z")

</div>

So, per [another thread](https://forum.inductiveautomation.com/t/scriptcontext-through-client-scope-does-not-return-project-but-does-in-perspective/62604/22) on here I am actually providing a project name in the constructor of my `GatewayScriptModule`, because ultimately this script is return project level resources.

In both of these examples I lose that parameter in my constructor, so is there another way to get it other than pulling it out of python locals when the script managers are initialized?

> [@paul-griffith](#):
>
> If so, you may want to (for simplicity) have something like this:

And in regards to Pauls example, when in the concrete `getConfig` method, you call `getConfigImpl`, it will end up calling the implementation of it, which calls back to `rpc.getConfigImpl`, which ends up in an endless loop of implementation calls. At what point do I actually end up reading my project resource through the implemented function?

---

<div class="post-metadata">

**Author:** ![bmusson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmusson/32/87530_2.png) [@bmusson](https://forum.inductiveautomation.com/u/bmusson)\
**Post date:** [August 5, 2022, 7:29pm UTC](https://forum.inductiveautomation.com/t/indexexception-whenever-using-pyargparser/62692/10 "2022-08-05T19:29:37Z")

</div>

> [@ScriptContext through client scope does not return project, but does in Perspective](https://forum.inductiveautomation.com/t/scriptcontext-through-client-scope-does-not-return-project-but-does-in-perspective/62604/12):
>
> And no, your script module cannot be your RPC handler. That way lies madness.

This kind of use case is why having the ability to treat your RPC handler and your gateway script module separately is important.

To modify my previous example to take the `projectName`:

```auto
class GatewayScriptModule {

	GatewayScriptModule(String projectName) {
		this.projectName = projectName
	}

	String getConfigImpl(String arg) {
        String value = // Gateway stuff using this.projectName
		return value
	}
}

class ModuleRPC {

    ModuleRPC(ClientReqSession session, String projectName) {
		this.session = session
		this.projectName = projectName
        this.gatewayScriptModule = new GatewayScriptModule(projectName)
    }

    String getConfigImpl(String arg) {
        return this.gatewayScriptModule.getConfigImpl(arg)
    }
}

```