solved A robust method to query the environment in JavaScript/JXA script filters

[chrillek]

The currently proposed (https://www.deanishe.net/post/2018/10/workflow/environment-variables-in-alfred/#javascript-jxa) method to query an environment variable relies on the getenv function from stdlib. Unfortunately, this approach will crash the script if the variable is not set. I suggest a more robust approach:

 

ObjC.import('Foundation'); // statt ObjC.import('stdlib');
const env = $.NSProcessInfo.processInfo.environment.js; // env is a JavaScript object containing NSStrings
const envVar = (env.foo && env.foo.js) || 'default';

 

This is fine for a single variable. If you need to inquire several, use a function like so:

 

ObjC.import('Foundation'); // statt ObjC.import('stdlib');
function getenv(variableName, defaultValue) {
  const env = $.NSProcessInfo.processInfo.environment.js; // env is a JavaScript object containing NSStrings
  return (env[variableName] && env[variableName].js) ||defaultValue; // .js converts the NSString to a JavaScript one
}

const foo = getenv('foo', 'default');

This variant is robust, i.e. it does not crash the script if the environment variable is not defined.

 

As this is not a question, the post might be better suited for the "advanced workflow tips" section, but I can't post there.

 

Edited November 12, 2022 by chrillek

[vitor]

The official support page covers that method, with an explanation.

[chrillek]

I saw that after my post, when I discovered this official page. Which is not exactly easy, given that there's no index and no table of contents for the documentation.

[pontus]

The second alternative in the official documentation lacks quotation marks around "myvariable"

[vitor]

Good spot, @pontus. Will be fixing that.