system.tag.getConfiguration -> valid JSON object

sherman · March 28, 2025, 6:53pm

I want to export my tag configuration as a valid json object so I can mutate it by script. When I try to run the following, it inevitably bounces off of some custom class objects that come out of the configuration. Is there a "full string" valid JSON mechanism for extracting this information? I can go through the effort of "repairing" the object with some aggressive recursive string casting but if there is a first-party mechanism for this I would prefer it. The script console clearly has some extra decoration to handle these things gracefully but I want to edit the configuration externally.'

conf = system.tag.getConfiguration("[HMI]myProject", True)
myJson = json.dumps(conf) # this inevitably bounces off something like Boolean or TagPath etc.

pturmel · March 28, 2025, 7:21pm

Deep copy to get pure python/jython dictionaries is required.
Use system.util.jsonEncode(), not python's stdlib.

sherman · March 28, 2025, 7:24pm

Thanks! Thats the kind of thing I was hoping to have exist.

myJson = system.util.jsonEncode(system.tag.getConfiguration("[HMI]", True))
>>> Traceback (most recent call last):
  File "<input>", line 68 in <module>
RuntimeError: maximum recursion depth exceeded (Java StackOverflowError)

but uh oh -- it's bricked my script console.

I've tried shrinking the depth on that configuration and it does not work at what I would consider to be an exceptionally reasonably sized configuration.

Kevin.Herron · March 28, 2025, 7:45pm

What about system.tag.exportTags instead?

pturmel · March 28, 2025, 7:54pm

Oh, I've seen that. Some kind of circular reference.

Try my Integration Toolkit's system.util.orderedcopy(). It tracks references and copies the loops correctly.

(But exportTags is almost certainly better.)

sherman · March 28, 2025, 8:25pm

That sounds like something I'd want! Thanks.

I tried it:

>>> conf = system.tag.getConfiguration("[HMI]", True) 
>>> system.tag.exportTags(None, conf, True)
Java Traceback:
Traceback (most recent call last):
  File "<input>", line 68, in <module>
	at com.inductiveautomation.ignition.common.script.builtin.AbstractTagUtilities.exportTags(AbstractTagUtilities.java:571)

	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.ClassCastException: java.lang.ClassCastException: class com.inductiveautomation.ignition.common.config.PyTagDictionary cannot be cast to class java.lang.String (com.inductiveautomation.ignition.common.config.PyTagDictionary is in unnamed module of loader java.net.URLClassLoader @1adaa42b; java.lang.String is in module java.base of loader 'bootstrap')


	at org.python.core.Py.JavaError(Py.java:545)

	at org.python.core.Py.JavaError(Py.java:536)

	at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:192)

	at com.inductiveautomation.ignition.common.script.ScriptManager$ReflectedInstanceFunction.__call__(ScriptManager.java:553)

	at org.python.core.PyObject.__call__(PyObject.java:494)

	at org.python.core.PyObject.__call__(PyObject.java:498)

	at org.python.pycode._pyx405.f$0(<input>:68)

	at org.python.pycode._pyx405.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:1703)

	at org.python.core.Py.exec(Py.java:1747)

	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:628)

	at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:616)

	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.ClassCastException: class com.inductiveautomation.ignition.common.config.PyTagDictionary cannot be cast to class java.lang.String (com.inductiveautomation.ignition.common.config.PyTagDictionary is in unnamed module of loader java.net.URLClassLoader @1adaa42b; java.lang.String is in module java.base of loader 'bootstrap')

	at com.inductiveautomation.ignition.common.script.builtin.AbstractTagUtilities.exportTags(AbstractTagUtilities.java:571)

	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)

	... 19 more

Traceback (most recent call last):
  File "<input>", line 68, in <module>
	at com.inductiveautomation.ignition.common.script.builtin.AbstractTagUtilities.exportTags(AbstractTagUtilities.java:571)

	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.ClassCastException: java.lang.ClassCastException: class com.inductiveautomation.ignition.common.config.PyTagDictionary cannot be cast to class java.lang.String (com.inductiveautomation.ignition.common.config.PyTagDictionary is in unnamed module of loader java.net.URLClassLoader @1adaa42b; java.lang.String is in module java.base of loader 'bootstrap')
>>>

Kevin.Herron · March 28, 2025, 8:29pm

second argument is not whatever you get from getConfiguration...

sherman · March 28, 2025, 8:39pm

Ah that's true, it needs to be a list of paths. Lets try again!

myJson = system.tag.exportTags(None, ["[HMI]"], True)

It works! At least it returns an object that I can write to a file myself; trying to write directly takes my linux path (running containerized) and seems to have flipped it to a C:\{my path with / -> \} path without my consent. i.e.

>>> print(system.tag.exportTags("/myFileSystem/tags.json", ["[HMI]"], True)) 
C:\myFileSystem\tags.json

I'm guessing that method hasn't been updated to support containerized/linux environments?

(Addional QOL: please consider adjusting all of the scripting functions that take lists of things to auto-list a single non-list argument) if not isinstance(arg, list): arg = list(arg))

Kevin.Herron · March 28, 2025, 8:44pm

You're running this in the Designer Script console, so I'm not sure your containerized environment is relevant. You're on Windows, so you get a Windows path. It wrote to a file on the host running the Designer.

Kevin.Herron · March 28, 2025, 8:47pm

Also this seems to be poorly documented and only inferred from an example, but if you omit the filePath parameter it'll just return the export contents:

# Exports the entire tag provider named "default" as a string, and
# returns the string to a "tags" variable.
tags = system.tag.exportTags(tagPaths = ["[default]"])

sherman · March 28, 2025, 9:24pm

Ah yes my old Achilles heel. My gateway message helpers that I use to write files managed to have me forget about this for awhile. I used the non-pathed option to get the data and write it to my real filesystem using that, but spaced on the direct write.