# Correct invocation of runScript? **URL:** \ **Category:** General Discussion\ **Tags:** ignition81, scripting, perspective\ **Created:** [May 13, 2022, 9:38pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561 "2022-05-13T21:38:39Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@peter](https://forum.inductiveautomation.com/u/peter)\ **Post date:** [May 13, 2022, 9:38pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/1 "2022-05-13T21:38:39Z")
OK I admit it, I'm getting confused over how to specify the script to run during the Startup event on an object. I have a View that has: - a script attached to the root object called "testMethod" (with no parameters) - A Startup event on the root object that attempts to call testMethod In the startup event I try to invoke it like > runScript("self.testMethod",0) But I am getting a jython exception of "NameError" I don't think that I am doing anything wrong, or misspelling anything. My complete scripts are: ```auto def runAction(self): """ Method that will run whenever the selected event fires. Arguments: self: A reference to the component that is invoking this function. """ #import java.lang.Exception try: myEvent = "onStartUp" myMethod = "self.testMethod" runScript(myMethod,0) except: print "### except: " + myEvent + " Failed to run " + myMethod print "### except: " + str(sys.exc_info()[0]) ``` and ```auto def testMethod(self): """ Custom method that can be invoked directly on this component. Arguments: self: A reference to the component that is invoking this function. """ print "### testMethod()" ``` and the wrapper log entry is simply ```auto INFO | jvm 1 | 2022/05/13 15:37:06 | ### except: onStartUp Failed to run self.testMethod INFO | jvm 1 | 2022/05/13 15:37:06 | ### except: ``` What am I doing wrong?!?!? ---
**Author:** ![andrews](https://avatars.discourse-cdn.com/v4/letter/a/898d66/32.png) [@andrews](https://forum.inductiveautomation.com/u/andrews)\ **Post date:** [May 13, 2022, 10:04pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/2 "2022-05-13T22:04:26Z")
What kind of object are you doing this on? ---
**Author:** ![peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@peter](https://forum.inductiveautomation.com/u/peter)\ **Post date:** [May 13, 2022, 10:05pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/3 "2022-05-13T22:05:16Z")
It is on the co-ordinate root container of a perspective View ---
**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:** [May 13, 2022, 10:06pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/4 "2022-05-13T22:06:20Z")
> [@peter](#): > > A Startup event on the root object that attempts to call testMethod Is there a reason you're doing this via an expression and runscript, vs just invoking your custom method directly? ~~I'm not sure the expression context automatically brings `self` into scope; maybe try `this`?~~ Nevermind, looks like `self` _should_ be correct. ---
**Author:** ![peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@peter](https://forum.inductiveautomation.com/u/peter)\ **Post date:** [May 13, 2022, 10:11pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/5 "2022-05-13T22:11:14Z")
Based on [this](https://forum.inductiveautomation.com/t/how-best-to-optimize-for-real-time-jog-buttons/59518/14) I need to resolve the server and path of a tag from its pathname in order to invoke system.opc.writeValue . As this should be constant over the life of a session I should only need to look the info up once and locally cache it. I was trying to do this in the object where the info was needed. I was choosing to do the work in a separate function than the startup event in order to better organize my code. And what do you mean by? > [@](#): > > Is there a reason you’re doing this via an expression and runscript, vs just invoking your custom method directly? can I invoke testMethod() directly from the Startup event? ---
**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:** [May 13, 2022, 10:19pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/6 "2022-05-13T22:19:00Z")
Oh, okay, nevermind. We're _both_ confused 🙂 `runScript` is an _expression_ function - it's designed as a bridge/escape hatch from the limited capabilities of expressions to the power of Jython: [https://docs.inductiveautomation.com/display/DOC81/runScript](https://docs.inductiveautomation.com/display/DOC81/runScript) If you have a script _action_ already (`def runAction` above) - you can just call your custom method directly: ```auto try: self.testMethod() except: print "### except: " + "onStartup" + " Failed to run " + "testMethod" print "### except: " + str(sys.exc_info()[0]) ``` If you _really_ want to make things dynamic, then you would use `getattr` on `self`: ```auto def runAction(self): """ Method that will run whenever the selected event fires. Arguments: self: A reference to the component that is invoking this function. """ #import java.lang.Exception try: myEvent = "onStartUp" myMethod = "self.testMethod" getattr(self, myMethod)() #second parens to invoke except: print "### except: " + myEvent + " Failed to run " + myMethod print "### except: " + str(sys.exc_info()[0]) ``` > [@peter](#): > > I was choosing to do the work in a separate function than the startup event in order to better organize my code. That part definitely makes sense - you may also want to consider moving your logic into project level shared scripts so that you can re-use these scripts across multiple views/components more easily. ---
**Author:** ![peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@peter](https://forum.inductiveautomation.com/u/peter)\ **Post date:** [May 13, 2022, 10:41pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/7 "2022-05-13T22:41:13Z")
OK .. that worked!!! I now better understand the use of runScript! But that leads me to a question. If I have a hierarchy like ```auto View +--root--+ | |--ScriptB | +--Object1 | +--Object2----+ |--EventA |--ScriptA ``` And I have event EventA on Object2 that uses a runScript to call a function ScriptA on Object2, from within ScriptA, can I now invoke ScriptB via something like: > self.parent.ScriptB() ?? > [@](#): > > you may also want to consider moving your logic into project level shared scripts so that you can re-use these scripts across multiple views/components more easily. I've already partitioned my objects across a handful of mutually exclusive functionality, so while your suggestion is something to keep in mind, it's going to be more complicated to come up with a simple library that encompasses all the functional that I want. ---
**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:** [May 13, 2022, 10:46pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/8 "2022-05-13T22:46:38Z")
> [@peter](#): > > self.parent.ScriptB() I _think_ this should work, yes. ---
**Author:** ![peter](https://avatars.discourse-cdn.com/v4/letter/p/278dde/32.png) [@peter](https://forum.inductiveautomation.com/u/peter)\ **Post date:** [May 13, 2022, 11:08pm UTC](https://forum.inductiveautomation.com/t/correct-invocation-of-runscript/59561/9 "2022-05-13T23:08:21Z")
I just tested it and it _did_ work!