Identifying when patch uses older version of plugin?

Hello! I’m updating a module to fix some backward-incompatibilities between older versions.

When loading older patches, an entry like this is added to the log file by VCV Rack:

[13.514 info src/engine/Module.cpp:167 fromJson] Patch created with voxglitch v1.32.0, currently using v2.21.1.

Is there any way that I can access this information from within the code? In other words, is there any function or callback which will alert me when an older version of my modules is being loaded?

I’d like to write code that says something like:

If a patch using voxglitch version less than 2.20.1 is being loaded, then...


as far as I know, there is no way to do it other than to think of it ahead of time. At least that’s been my painful experience.

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Thank you, I appreciate the information. I should add some type of version number to the JSON save files that I can reference in the future. :+1:

If you already save your own json you are cool. read it back - if the schema number isn’t there, then it’s the OG 1.0 versions. Then for new stuff, just write back “schema”: 2 or something and your are cool.

If you just use params you can do the same thing, but there you need a params “schema” that is set to 1.0 from the get-to.

Unfortunately, the schema remained the same. The only difference was that the JSON value changed from an integer to a float. So, what I ended up doing, is checking if the value was greater than “1”, and if so, mapped it to the desired range from 0 to 1.0. This works great… unless the original integer is exactly 1, which is luckily unlikely.

Anyhow, my solution should work, but I was looking for something a bit more elegant. :slight_smile:

well, I certainly learned my lesson from the pain - first param I make is SCHEMA_PARAM.


I saw that in a previous post when I was looking for a strategy for dealing with this. I’ll follow your lead. :man_bowing:

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