Use .JSON as a module config value?

[drippyer]

Hey there!

I am trying to automate a super small part of my MagicMirror which involves the MMM-PlexNowPlaying module.

Basically, I’m trying to take a JSON file from the filesystem, read it to a JS Object, then use that Object as the value for the userNameFilter key within the config Object.

---

Code

This is the code I’ve made and added to my config.js to avoid writing an entire module lol:

if (typeof module !== "undefined") {
    var plexUsers = require('/home/pi/mmConfig/user_list.json');

        let obj = config.modules.find((o, i) => {
                if (o.module === "MMM-PlexNowPlaying") {
                        config.modules[i].config.userNameFilter = plexUsers;
                        return true; // stop searching
                }
        });

        let test = config.modules.find(o => o.module === "MMM-PlexNowPlaying");
        console.log(test);
}

It’s located between var config = {}; and
if (typeof module !== "undefined") {module.exports = config;}

---

Confusion

The two scenarios I have compared against each other are

1. running the code above without
2. commenting out let obj = {}; and hardcoding the Object (the normal way)

And in both cases the output of test is the exact same. Yet the behavior of the Mirror doesn’t seem to reflect that. The standard usage of 2 works as expected, yet 1 does

Any and all help would be greatly appreciated!

[drippyer]

@sdetweil Thanks for the info!

Ok, I see. That could definitely work.

I went ahead and scrapped the code from above and converted it to a bash script that is executed before the cd ./MagicMirror (pretty sure I’ve had this setup running since before installers/mm.sh was actually provided lol). I admit the bash script is suuuper rough and was written with my symlinked config files in mind but it gets the job done!

1. makes an intermediate copy of config.js
2. grabs the content of the of the json
3. declares variable containing config variable to be replaced
4. prepends the variable string to the json content
5. uses perl/regex to search for the variable in the intermediate file and replace it
6. makes a backup of config.js just in case
7. moves intermediate copy to working version

#!/bin/bash

cp /home/pi/mmConfig/config.js /home/pi/mmConfig/config.inter

mapfile < /home/pi/mmConfig/user_list.json

variableName="userNameFilter"

replace="${variableName}: ${MAPFILE[@]}"

perl -0777 -pi -e "s/${variableName}: {((.|\n)*?)}/${replace}/g" /home/pi/mmConfig/config.inter

mv --backup=numbered /home/pi/mmConfig/config.js /home/pi/mmConfig/config_backups

mv /home/pi/mmConfig/config.inter /home/pi/mmConfig/config.js

And that successfully allows for the data to be read in! Thank you!

Sadly, it did break pm2 watching config (which kinda makes sense to avoid a loop) and if I’m modifying the config I’m already in the command line and a pm2 restart mm isn’t too bad I suppose ¯\_(ツ)_/¯

Edit: I’m realizing I should add a check to make sure it doesn’t perform either mv if the file is the same. New to-do lol!

[sdetweil]

@drippyer I don’t know about putting the code IN config.js,but you can add another step to the script that starts mm and create the updated config.js

installers/mm.sh is the normal start script

it does

#!/bin/bash
# This file is still here to keep PM2 working on older installations.
cd ~/MagicMirror
# add your script here
node xxx.js
DISPLAY=:0 npm start

make your original config.js config.model
and merge your user info to get config.js

[drippyer]

@sdetweil Thanks for the info!

Ok, I see. That could definitely work.

I went ahead and scrapped the code from above and converted it to a bash script that is executed before the cd ./MagicMirror (pretty sure I’ve had this setup running since before installers/mm.sh was actually provided lol). I admit the bash script is suuuper rough and was written with my symlinked config files in mind but it gets the job done!

1. makes an intermediate copy of config.js
2. grabs the content of the of the json
3. declares variable containing config variable to be replaced
4. prepends the variable string to the json content
5. uses perl/regex to search for the variable in the intermediate file and replace it
6. makes a backup of config.js just in case
7. moves intermediate copy to working version

#!/bin/bash

cp /home/pi/mmConfig/config.js /home/pi/mmConfig/config.inter

mapfile < /home/pi/mmConfig/user_list.json

variableName="userNameFilter"

replace="${variableName}: ${MAPFILE[@]}"

perl -0777 -pi -e "s/${variableName}: {((.|\n)*?)}/${replace}/g" /home/pi/mmConfig/config.inter

mv --backup=numbered /home/pi/mmConfig/config.js /home/pi/mmConfig/config_backups

mv /home/pi/mmConfig/config.inter /home/pi/mmConfig/config.js

And that successfully allows for the data to be read in! Thank you!

Sadly, it did break pm2 watching config (which kinda makes sense to avoid a loop) and if I’m modifying the config I’m already in the command line and a pm2 restart mm isn’t too bad I suppose ¯\_(ツ)_/¯

Edit: I’m realizing I should add a check to make sure it doesn’t perform either mv if the file is the same. New to-do lol!

[sdetweil]

@drippyer you could change the pm2 setup to not watch config.js
…

[drippyer]

@sdetweil I might have been a bit unclear haha. The break was pm2 no longer watching config.js, not a loop. My bad about that misunderstanding.

[sdetweil]

@drippyer got it…